Recondition Battery Guide

EZ Battery Reconditioning Method

EZ Battery Reconditioning is a program that teach users how to bring back to life their dead batteries of all kinds. The program is authored by Tom Ericson, previously an employee of golf cart enterprise. He learnt the strategies of converting old batteries to the level of brand new ones and want to share. The program is workable for many types of batteries such as phone batteries, rechargeable batteries, laptop batteries, alternative energy batteries, AA batteries, AAA batteries, solar system batteries, and wind system batteries among many others. Apart from providing you with written instructions, the program also offer photos, diagrams and videos that make the entire process easy to comprehend. In addition to the reconditioning guide, you will also be availed with information on how you can get old batteries for free. You can then apply the strategies covered in the guide to recondition them freely. Reviving batteries save money. Better still, you can sell these batteries for profits. Evidently, this program can help you in a significant way. Give it a try and you will never regret. Read more here...

EZ Battery Reconditioning Method Summary

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Contents: Ebook
Author: Tom Ericson
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My EZ Battery Reconditioning Method Review

Highly Recommended

The writer has done a thorough research even about the obscure and minor details related to the subject area. And also facts weren’t just dumped, but presented in an interesting manner.

Purchasing this e-book was one of the best decisions I have made, since it is worth every penny I invested on it. I highly recommend this to everyone out there.

Ultima Nicad Battery Charger

Ultima Electronics1 new low-cost UL-100 battery charger can recharge up to 4 nicad Two convenient LED Indicator lights monitor battery pairs In each charging compartment to determine proper charging. A third LED indicates single 9-V battery status. Indicator lights that fail to go on warn the user to check battery polarity for loose contacts.

Rechargeable Battery

Here's a great deal on new 12 vol 9 amp hour rechargeable lead acid batteries. These batteries were recently man-ufaolured and prepped lor use jn a product which hasnl yei come to market. The OEM didn't want to hold Lhem in Stocky so we gol lhem at a greatly reduced price. They arc 5.9 x 2,55 x 4.42 high and have a strip of foam padding stuck to one side. They have standard 1 4 quick-connect solder terminals. Weight. 6 lbs. Sealed gel cell batteries can be used in any position and can be recharged or trickle charged for long periods

Battery Chargers

C. lighting service in their homes who use a storage battery on their set, should own a battery charger. The chargers come in two different styles, the mechanical vibrator and the bulb rectifier types. Both are safe to use in the home and charge the battery equally well. The rectifier using the bulb is more silent in its operation than the mechanical vibrater type. The bulb type also is less apt to get out of order. The bulb rectifier may take a little longer to charge a battery than the vibrator type due to the fact that it rectifies only one side of the 60 cycle current. Bulb rectifiers come in two sizes, one giving 2 amperes at 6 volts and the other 6 amperes at 6 to 8 volts. The larger size charges the battery three times as fast as the smaller type. With either charger, about 10 cents' worth of current is required to charge a storage battery.

Approximate Output Voltage Vs Load Current For A Pea Dynamotor

The three wires now coming out of the dynamotor are identified as follows The smaller wire is the positive high voltage. The heavy wire leaving the same grommet is positive 6 volts and negative high voltage. The single heavy wire leaving the other grommet is negative 6 volts. Whether the car is positive or negative ground, negative high voltage can be taken as car-frame ground. With the negative of the car battery grounded, the plate current can return through the car battery and the armature winding. This simply puts the 6 volts in series with the 500 volts and gives 6 extra volts plate voltage.

Low Battery Software Control

To further extend card reader usability with a set of old batteries, software controls power use by pulsing the motor. When the batteries approach the low-battery state, software begins to turn olf the motor for short periods of time to lower the motor duty cycle and decrease power consumption, giving the batteries more time to recover between pulses. As the battery voltage drops lower and lower the motor off time increases. Even though he motor is being turned off for short periods as the card goes through, it is easily possible to have a correcl read, and the difference may even be imperceptible to ihe user. The 82104A verifies a good read on every card by computing a checksum during each card pass and comparing it lo the sum recorded in the last 28 bits of information on the data track. To tell ihe user what is happening, the message LOW HAT is displayed at the end of any read in which the motor has been turned off, whether the read was good or bad. Many good reads may be possible...

Single Tube Regenerative

In receiving, the first operation is the adjustment of the vacuum tube. The rheostat is advanced until a hissing sound is heard in the phones, and then backed off until this sound just disappears. It will not be necessary to change this again except to compensate for changes in battery voltage.

High Power Surveillance Ir Scope

This Infra-Red scope was designed specifically for long range surveillance use. The built-in, totally invisible, 5 0 watt halogen lamp iK source is coupled with a premium grade type 6032 image converter tube, 265 mm f4 .2 lens, and 16 power military spec color corrected eyepiece make this an ideal unit for viewing of clandestine activities or animals. The scope is capable of detection at more than 30 0 feet, recognition at 30 0 feet and positive facial identification at 150 feet. It runs on 1 2 VDC which makes it ideal for mobile use. It comes with a remove-able hand grip which allows for tripod mounting, 2 power cords for cigarette lighter or battery terminals, instructions and a 90 day Warranty. Listed below are accessories which make this a very versatile instalment. The scope and accessories are new and guaranteed functional. Net wt. 5-1 4 Lbs,

Circle On Reader Service Card

I thought about using the ICL7660 and four A A batteries to power the setup as had for the digital ammeter on my boat (see Penny Pincher s Digital Ammeter 73, May 1998). That approach would not power the meter dow n. hut four AA batteries w ould have more capacity or I could use rechargeable batteries, That would work, but the arrangement would he bulky arid I would have to strap the butteries to the back of the meter. Not a verv neat or easily portable solution.

The Nature Of Electricity

The electricity that is produced by a dry cell or storage battery differs in that it moves or flows very rapidly through the wire connected to the battery. Such electricity is called dynamic electricity (meaning moving electrically. The movement of electricity through a wire is called an electric current. All electricity used for commercial purposes is in the form of electric currents. It is the electric current flowing through an electric lamp which causes the lamp to give off light, just as it is the electric current flowing through the motors that causes a street car to move along so rapidly. We want to bear in mind, then, that there are two kinds of electricity, static and dynamic, and that it is dynamic electricity in the form of electric currents which is used so extensively commercially. Electric currents can be produced by means of dry oells or storage batteries, and in larger quantities by means of machines called electric generators or dynamos.

Automatic Sideband Selection

Operates on 12 14 VDC for mobile or storage battery use. For 117 VAC use, an external supply is required. FULL ACCESSORY LINE. Model 217 500 Hz CW filter 55, Model 219 200 Hz CW filter 60, Model 218 1.8 kHz SSB filter 55. Model 243 Remote VFO 139, Model 255 Power Supply Speaker 169, Model 280 Power Supply 139, Model 645 Dual Paddle Keyer 85r Model 670 Single Paddle Keyer 34,50, Model 234 214 Speech Processor & Condenser Microphone 163, Mode) 247 Antenna Tuner 69, All in matching color

Down East Microwave

We had 16 very old NiCds on hand for learning to use the zap pen Eight of these were more than 20 years old, a good set to see just what the zapper would really do, AH of these NiCds measured 0.000 volts, and obviously had internal shorts. We tried all eight NiCds for an hour or so without any signs of recovery. Additionally, we zapped all of them with the automobile battery technique, without success. The automobile battery technique had never failed before it pui quite a large jolt of current through the cells. These NiCds were more than dead

Circle Ok Reader Service Card

Walkies usually have fuses between the DC input and the rest of the rig. These sometimes look fike tiny glass resistors, while other times they look exactly like regular resistors, What they don't look like, of course, are fuses With the power and battery disconnected, a simple ohmmeter check will teil you if there's any connection from one side to the other fve seen these tiny fuses blow with no provocation. As with the battery packs, it's important that you replace the fuse, rather than just jumpering across it

Please Call Or Write For Our Complete Free Catalog

Notice one other difference in this circuit The LM3914 measures voltage relative to its ground, But in a mi ti-battery pack only one battery has its cathode at the system ground. To measure the other batteries* the ground lead of the LM3914 is actually at the potential of the battery cell below it. This causes a small additional current to flow through this eel J, but I have set R3 in my PFA so that its total cuftchi is only about 10 mA. This current does not disturb the system and the PFA has no problem getting accurate readings of all cells. It is also why I used a manual switch for SW2 instead of connecting it to U2,

Alinco offers four great choices

Alinco's top of the line Intelligent Receiver tunes from 100 KHz -2.15 GHz with excellent sensitivity and a triple conversion front end. Receives WFM, NFM, AM, USB, L5E3r CW and FM stereo*, 2000 memory channels with alpha-numeric labeling, download free computer control software from the Alinco web site. Flash Tune' locks onto and monitors strong local signals On board Help feature, digital recorder, frequency counter, CTCSS search & decode, Channel Scope spectrum activity display, Ni-Cd battery & quick charger included. BNC antenna port with new, wide-range ducky antenna included.

Write For Club Discounts

* No more dead batteries due to t was just about to give my FT-207R away, when decided to give it one last chance, and i ordered the BS-l battery saver kit. Well, it made ati the difference in the world, I canTt believe it is the same rig. I used to carry around an extra battery pack all day, but now my batteries last about twice as long. 1 no longer have to worry about dead batteries. I used to worry about turning the memory off to conserve power, but with the BS-1 it doesn't matter any more. The audio has improved and reaiJy like my rig again,1'

Available In Kit Form Also

Results have been very satisfactory when using this charger in a variety of ways including trickle charging. All battery types have responded well when recommended charging rates and duty cycles as recommended by the battery manufacturers have been adhered to. The only variable results experienced were when attempts were made to recharge the lowly carbon zinc cell.2 Apparently rejuvenation of these cells is quite dependent upon the duty cycle and age of the cell.

Gregory Electronics Corp

The TR-22 is about half the size of the smallest mobile units, and includes virtually all the performance features of the big rigs while retaining that elusive ingredient caiied portability. The unit has 6 channels, independent squelch and volume controls, and a panel meter to indicate the capacity of the integral batteries. The unit is pov ered from an internal battery pack, external auto battery, or 115V ac. In addition to the front-mounted telescopic whip, the unit has a conventional UHF connector on the rear to facilitate operation as a mobiie or base station. As a mobile unit, the TR-22 fits easily under the dash of even the most compact car. it connects directiy to the car battery and an external antenna. The speaker is splash-proof, and the unit can be removed from the case without tools two unique push dips hold the unit in its one-piece housing. As a mobile, the unit can be connected under the dash. A standard UHF connector is provided on the rear panel of the chassis along...

Vlf Metal Detector Circuit

C1972 Transistor Transmitter Schematic

The actual specs furnished say total dissipation, 3 watts7 ThaCs for each transistor You're out of the dry cell class then, but the Globe Co. has remarkable non-spill-able lead oxide storage batteries that wili surprise you, for portable and emergency work. So here are the details. Recently, needing maximum power in a minimum package (always an interesting idea ) 1 kept pushing the 50 MHz oscillator power up and up until there was over a watt going into it and over l 2W coming out, which was driving the final in great style. Remembering the old trick of putting a pilot light bulb in series with the crystal, I soldered in a No. 48 bulb, as can be seen in Fig. 1, and sure enough, it lit up. Just a dull red glow, but checking with the Amateur's milliwatt-meter 1 found between 10 and 25 mW, depending on the tuning and output loading, as well as the battery voltage. This can also tell you interesting things about the oscillator such as how much of the generated power is being devoted to...

Circuit Considerations

In this instrument the precision 11 -volt reference is derived from a zener diode reference supply (Fig. 5). Since the instrument operates on battery power, an oven for the zener diode was not used. To eliminate the effect of environmental change on the reference voltage, a technique was developed to adjust the dc temperature coefficient of the 11-volt reference to below 1 ppm per degree C, over the range +20 to 30 C. Over the complete temperature range +10 to 40 C, the temperature coefficient is below 2 ppm per degree C. Another factor in assuring high stability is the ability of the total circuit to remain stable from full battery voltage of 31 volts to a minimum of 24 volts. Over this range, the 11 -volt reference changes less than 1 part per million.

Hamtronics TA Exciter

Things had been going well in gen eral, hut over die lasi lew hunts we'd had problems* Three of the last five hunts had to be called off or modified because our fox transmitters had failed during ihe hums, In one case c were using an old thumbwheel-t pe handheld as the fox. Apparent the thumbwheel contacts were dirty, cans-ing (he transmitter to jump channels imermittently. his made the transmitter mysteriously drop off the air at strange intervals, and caused some trouble for the packet channel the rig was suddenly transmitting on. One of the group then buill up a little postage stamp-sized transmitter. This worked OK, but ihe frequency began to drift as the batter) voltage dropped. The hunters with the synthesized rigs were able to follow the transmitter down the band, but (hose of us with rock-bound rigs were left on the wayside. As a last resort, one of the guvs donated an old mobile rig, matched up with a car battery. It was still putting out about twenty watts, so he hid the...

Communications Electronics

Frequency range 148-1 4 MHz continuous coverage Will also work 134-148 MHz. with reduced performance. The RELM RSP500B-A is our most popular programmableS watt 20 channel handheld transceiver, You can scan 20 channels at up to 40 channels per second. It includes CTCSS tone and digital coded squelch Snap on batteries gtve yon plenty of power Additional features such as time-out timer, husychannel lockout, cloning, plug-in programming and I8M PC compatabriity are standard tt is F.C.C type dCCepted for data transmission and D.O.C approved We recommend also ordering the 8C45 rapid charge 1 Vj hour desk battery charger for S99 95 a deluxe leather case LC45 *0r 4S 95 and an external speaker microphone with clip SM45 for S59 35 Since this radio IS programmed with an external programmer, be sure to also order one PM45 at 74 95 for your radio system CEI understands that all agencies want excellent communications capability, bul most departments are strapped for funds. To help, CEI now offers a...

F I ash a new Strobotac electronic stroboscope

Stroboscope Block Diagram

The new Strobotac and optional accessories. Next to the Strobotoc, in leather case, are battery and charger. Above right are battery power cable and extension lamp. The Strobotac itself sits on the high-intensity- The new high-speed Strobotac electronic stroboscope described in this issue extends the speed range for stroboscopic viewing and speed measurement to over 1,000,000 rpm. In addition, the versatility of the stroboscope is enhanced by three optional accessories a rechargeable battery for operation independent of ac power lines, a plug-in High-lntensity-Flash Capacitor for extra-bright flashes for photographic applications, and an extension lamp for access to hard-to-reach areas. it is useful. The newest member of GR's Strobotac family of stroboscopes follows the tradition. Its ability to flash 150,000 times a minute means that it can be used for speed measurement and stroboscopic observation of the fastest existing motors and machines, even those in the million-rpm class,...

Testing The Comcraft

The power supply is built in for 117V ac operation, plus the usual 12V dc power cord for mobile use, A little battery test button on the front panel iets you check the battery condition. This test button may not be of great interest for mobile applications, but if the unit is used in conjunction with the accessory CBP-12 Comcraft battery pack, it will tell you how things are going. This battery pack is automatically recharged by the ac supply, by the way.

Meter Announced By Dynascan

Dynascan Model 177 Vtvm

The B&K Precision model 820 comes with a 26-page detailed manual. Optional accessories include the BP-28 rechargeable battery pack, the BC-28 Charger, and the LC-26 carrying case. The 820 is now available for immediate delivery at local B&K Precision distributors, For additional information, contact B&K Precision, Sales Departmentt 6460 West Cortland Street. Chicago IL 60635( (312)*889-9087. Reader Service number B45

Tempo Channel Handheld Transceiver

The amazing pocket-sized Tempo S1 SYNCOM offers the firsl fully-synthesized 800-channel 2 meter miniature amateur hand held Iransceiver, Other units which are larger, heavier, and similarly priced (by the time you add crystals, bat teries, chargers, and antennas) can offer only 6 channels. The SVs price of 349 includes the battery pack, charger, telescoping antenna and 800 channels

Cobra Radar Detectors

Excludes 823.9975-549,0125 and 868.9375-094.0125 MHz. The Bearcat 200XLT sets a ftflw standard for handheld scanners in performance and dependability. This full featured unil has 200 prog ra mmabchan nels wth 10 sea n ni ng banks a nd 12 ba nd coverage. If you want a very similar modei without the 80Q MHz. band and 100 channels, order the BC1OQXLT-B for only St 79.95, Includes antenna, carrying case bert Focp. ni-ced battery pack. AC adapter and earphone. Order your scanner from CEI today. BP70 B Ni-Cad battery pack for BC70XLT scanner ,. 39.95 BC142XL-B Searcat 10 channel 10 band scanner +, SB4H95 BC147XLT-B Bearcat 16 channel 10 band scanner 94,95 BC172XL-B Searcat 20 channel 11 band scanner 124,95 BC177XLT-B Bearcat 16 channel 71 band scanner 129,95 BC590XLT-B Bearcat 100 channel 11 band scanners 194.95 BC760XLT B Bearcai 100 channel 12 band scanner 254,95 BP205 B Ni-Cad battery pack for BC20CV100XLT 39.95

E M Signaling Measurements

Barrier Connection Diagram

Several types of signaling are in common use The 3779A B Is designed to interlace with the most common form, called e & M signaling This form is a teletype-like signal based on two states on input and output sink or source current) and off (input and output open circuit) Since a lot of signaling equipment is buill with relays, the voltage level used Is the full exchange battery voliage (about 50V). The battery voltage can be positive or negative, depending on the system, and the on state may be asserted either by pulling the M input of the multiplex to ground, known as ground signaling, or pulling the M input to the battery voliage known as battery signaling. Likewise the E output of the multiplex may go to battery or ground potential, depending on the system In use A simplified E & M system is shown in Fig. 1 When the M input of Exchange 1 is connected to the battery voltage (battery signaling), the signaling bits in the PCM send link for thai channel are set. These bus are decoded...

Pa Nordwaeger Gunnar Svemssn

Monitoring is only half of ihe bird-tracking task. Once heard, signals must be positively identified for the data to be useful. Most animal transmitters don't send any station ID, To provide maximum battery life, the transmitters simply blip about once a sccond. That pulsed signal you hear on your receiver might be an owl tag, but it could be on a completely different animal.

Commodore Ham Programs

BATTERY PACK RE UJLDiNG Don't pilch II Mail It for FAST PROFESSIONAL REBUILDING' Satisfaction guaranteed' ICOM BP2 BP3 S19 95. BPS S25 95. BP7 BP& 6P70 32 95 ENWOOD P821 15 95. PB21H 521 95, P 25 25Hi26 24 95 YAE-SU FNB9 S 19.95. FNB10 23.95, FNB4 4A 36.95, Ten-Tec S24.95. ' U DO-IT INSERTS ICOM BP3 16-95. BPS 22 95, BP7flfl 27 50 KEN WO PS21 S1295. PB24 25 25 S 19 95. TEMPO Sl-Sl5 22 95. YAESU FNB4 4A 32 95. FNB10 18 95, AZDEN 3005t9.95. ' NEW PACKS ICOM BPS 43.95, BPS (BASE CHG ONLY) t39.95r YAESU FNB2 1 9 95, FNB V FNB14 S44 95. 5ANTEC M3 120 S22.95 TELEPHON E P AG E R COMPUTER t COMMERCIAL PACKS FR E CATALOG Add S3 ShrppmiV order PA + 6 i ViSVM C add t2 CUNARD. R D 6 Box 104, Bedford PA 15522 (014) 623-7000, BNB931

An Improved Audio Oscillator

Tuning Fork Oscillator

The best frequency stability and the lowest harmonic content are obtained when the amplitude of fork vibration is small, corresponding to a driving battery voltage not greater than 4 volts. Maximum power output consistent with these conditions is obtained with a total output battery voltage of 6 to 8 volts.

Write For Free Catalog

The lightest transceiver of the lot, with easily a couple of hundred milliwatts of rf power output (though it's rated for 100 mW). Extremely sensitive receiver. It does a great job where a good repeater is within range. Very tiny (fits into the pocket). Expensive also no mercury or alkaline battery replacement is available.

Startek International

A 1 ppm TCXOtime base is standard, with provisions for an optional ultra-high-stability TCXO. A factory-installed internal NiCd battery pack and 110 VAC adapter charger are also standard. Although small enough to fit in a shirt pocket, these bar graph counters out-perlorm many larger, much more expensive models.

Zeus Asp-1000 Generator

Ancien Fusible Electriques Ronds

Model CUT, Iran sis tunzed, built in battery or car battery through BS-9 adapter. CUT converts 2 meters to broadcast band. Can covcr from 108-1 74 mc. Model CLT same as CHT except converts any ham band from 2-54 mc down to the broadcast band or any other i-f output. Model SNL squelch & noice limiter, 6 or 12 vdc. SNLT all transistor. CLT or CTIT . . 35.95. BS-9 . . 2,95. SNL . 17,75. SNLT . . 19,95.

By Bernard E Musch and Robert B Taggart

Tors, mechanical adding machines provided output on paper tape. What is new in the HP-91 is the thermal printing technology that provides a small quiet printer with 5.7-cm-wide tape, the desk-top-sized keyboard for ease of touch entry, and a large, easy-to-read display all in a 23x20x6-cm package that fits easily into a standard attache case and weighs only 1.13 kg including a self-contained battery pack.

E B Battery Eliminator

Ux213 Rectifier

In order that an alternating current, such as that obtained from the ordinary AC lighting circuit, may be available for supplying the B battery power for a radio receiver it must first be rectified, that is, made unidirectional in character. One method of doing this consists of utilizing the limited one way conducting power of the rectifier tube. If this tube is operated as a single wave rectifier one-half of each cycle is suppressed so that, with a sixty cycle AC source, sixty unidirectional pulses of current are passed through the tube per second. Between every two of these pulses there exists a dead interval approximately one-half a cycle or 1 120 of a second long during which no current flows through the tube. A new tube of great interest to all owners of storage battery sets has been announced by the Radio Corporation. It is the 200A detector tube. This tube is said to have all the good qualities of the old type 200 without its high current demand and sensitivity to plate voltage...

Battery Monitor and Charger Controller

Many hams have a 12-volt automobile battery under the operating table for a variety of uses. There is a continuing need to know the batter voltage and to keep it Thiv unit displays the battery voltage on a 10-segmenl bar LED in increments of 0,5 volts over the range of 10.0 10 14.5 volts. When ihe batten voltage drops to 12.0 volts the unit automatically enables the 110 V AC line to the charger and begins charging the batten. As the batters voltage rises io 14.0 volts, the unit disables the 1 10 VAC line, turning off ihe charger. A discrete LED provides a visual indication ol the on-ofT state of the charger. I he 110 VAC line control is all solid state, eliminating mechanical relays and the ine liable pitting and dim relay contacts. The circuit automatically switches to the Charge condition upon application of 12 VDC to the unit when the input is 14.5 volts. Thus, the various LEDs light following the battery voltage as it discharges and is recharged. The bar LFD provides the battery...

Telephone Line Test Handset

AT&T 206A2 These rugged line test handsets were originally designed for Use wltfi AT&T's Craft Access computer. They can be used like any other line tes handset, but they have special features which may or may not be usefui. In addition to the touch'tone keypad, talk monitor switch, alligator ctip leads, 4 conductor modular jack and tool helt clip, these units have a LCD screen and function button joystick for use with AT&T's Craft Access computer. For the average user the extra features mainly allow you to adjust the volume and program in phone hurn-bers. The main drawback to these units is that they contain batteries that require recharging, and the test set should be recharged when not in use. The size of the unit Is 12.5,h long X 4.5 wide. Brand new, in the box. They include 2 ni-ead battery packs, a charger and instructions.

Innovators In Digital Communication

(found the Nicad Conditioner article by W2KPt 73, April, 1981) quite interesting, having previously constructed a similar device T he nicad conditioner discharges a battery pack each time before then recharging it, I recently needed to construct another tor the local security force which was in terested in cycling its batteries Since they already had a battery charger set up to rapid-charge batteries. I decided to build only W2KPt's simple discharger (shown in hts Fig 1, repro-dut ed here Several problems immediately developed with hi* simple circuit First, i would not stop thf discharge at the desired cut A single nicad cell may be safely and fully discharged by merely placing a suitable load resistor across it (Fig 3) and waiting for the voltage to go to zero. This, however, is not suitable for discharging nicad battery packs If we let the nicad pack discharge to zero, a than 1 volt per cell (10 to 12 V for a 12-cell, 15-volt battery pack). 1) When the battery reaches the point of...

Penny Pinchers Digital Ammeter

Because 1 do a lot of mobile ham operating, bauery usage is very important to me. During the past few years, when cruising on my boat I have often found my battery voltage becoming lower than ii should be. As a consequence, 1 have been told hy the Waterway Radio and Cruising Club net controller that I was FMing, check your batteries. (The Waterway Radio and Cruising Cluh meets daily at 0745 Eastern time For about an hour and is dedicated to helping and passing traffic for marine mobile amateurs primarily along the east coast of the US and in the Bahamas*)

Tiie Icom Icwa Dual Band Handheld

No matter which rig I happened to have at any given moment, all the action seemed to be on another band If I had my 2 meter HT, I would miss my normal commuting skeds on 440 MHz. Yet whenever 1 had my 440 MHz HT with me, 1 would always find some need to get on the more heavily populated 2 meter band. The thought of carrying around the extra weight of two full-size handie-talkies and a couple of heavy-duty battery packs was not an appealing one. The ICOM IC*W2A is a full-featured dualband handheld measuring only 6.7 high, 2.1 wide, and 1.4 thick. The rig weighs in at only 1.2 lbs. As delivered, frequency coverage is 140-150 MHz and 440-450 MHz transmit, 136-174 MHz and 440-450 MHz receive. Despite its small size, the W2A offers a full 5 watts output (at 13 volts) on both bands, four scanning modes, 60 memories (30 per band)t simultaneous receive on both bands, fuill crossband duplex operation, and a host of other functions. Unlike many other HTsh the W2A comes equipped...

Simple Qrp Transmitter

Simple Qrp Radio

This article will describe a two transistor transmitter that is not difficult to build, and can supply up to one watt rf output for the QRP or portable sportsmen. The transistors are not excessively priced and are very reliable even though operated beyond their ratings. The use of an unusual type of keying provides chirpiess keying with a negligible backwave. The transmitter operates from a I 2 volt source making a car battery or iantern batteries ideal for portable use. With this configuration, tuning is not critical and the transmitter is completely stable. The output tank circuit is relatively inefficient but provides good selectivity and is simple to tune and construct.

By Michael D Wilson and David M George

Two options are available a temperature-compensated crystal oscillator (TCXO) and a battery pack. The battery is automatically switched in and will power the instrument for about eight hours any time ac power is not present. The battery pack and charging scheme used in the 5314A are similar to (but simpler than) those of the 5315A Universal Counter, as described in the accompanying article. high current level or a very high float voltage level. The required current level exceeded the power limitations of both the power transformer and the instrument package. The high float voltage would severely reduce the life of the battery in standby applications. While the constant-current technique would provide recharge times suitable for once-a-day cycling at a moderate current level, problems exist in sensing end-of-charge reliably at that current level. This could result in reduced battery life due to overcharging and or less than optimum performance in standby applications. The charging...

Instruction Book For Mab Or

MINIATURE VIBRATOR PACK FOR MAB OR DAV, eliminates nuisance and expense of dry batteries. Operates from miniature fi volt storage battery, net supplied, available from many surplus dealers. With Instruction Book, Shpg. wt. 5 lbs. UNUSED. EACH 7.95 Here's the chance to build your own real compact, lightweight hand-held Wslky-Talkyl Designed to transmit and receive on one (cmtal-controlled) frfcuency between 3.0 and G.Q mc,r any real TLirn could revamp the coils for operation on higher frequency amateur phone bands. This will result In iner ascd antenna power output and longer distance transmission. By building your own case for this chassis, with space fur larger batteries and increased E voltageH further increased power and longer service from batteries will result. These chassis are NEW, unused, complete with telescoping antenna hut less tubes, coils, or crystals. Tubes reuired 1--1R5, 1 IS5, 1 1T4, and 2 3S4. 2 miniature plug-in coils required

Circle Oh Reader Service Card

1990, p. 9.) You can provide reliable communications at a moment's notice from any weird location , . . with this innovative project. tkThe BackPacket consists of a PacComm Micropower-2 TNC, an Epson PX-8 laptop, a Yaesu FT-203 HT, a 7 amp-hour sealed lead-acid battery all encased in a sturdy Ensolite laminate in a Jansport daypack. Portable Packet Digipeater for Emergency Service, (by John Neeley K6YDW, June 1993, p. 16.) Build this highly portable, battery powered digipeater. Parts list, schematics, and PC board design are all included.

Portable Two Meter Quad

A new collapsible antenna has been introduced by Palomar Engineers. Jt extends the range of low-power two-meter transceivers by providing the gain and front-to-back discrimination of a two-element quad, It is idea for boating, backpacking, moun-taintopping, and other portable applications since it gives the gain of a linear amplifier but does not require additional battery power.

Top Quality Frequency Counters At Pace Setting Prices

Note Model K-7000 is available KIT FORM only, other models factory assembled only. Model K-7000 requires AC-70 Adapter ( 4.95) for 115VAC Operation, AC Adapters are included with the other models. See chart below for NI-CAD Battery Pack Option, etc. Note Model K-7000 is available KIT FORM only, other models factory assembled only. Model K-7000 requires AC-70 Adapter ( 4.95) for 115VAC Operation, AC Adapters are included with the other models. See chart below for NI-CAD Battery Pack Option, etc.

Handheld Countertimer

A high-contrast .43-Inch LCD display oiler* 8-digit precision for fast and accurate readings LCD annunciators indicate overflow. gate-open, and low battery conditions With a simple flick o a switch, the display-storage mode will maintain the last wading n the display indefinitely.

Custom Leather Radio Cases

THE ORIGJNAL HAM SACK, Deluxe soft padded case for all popular hand-helds with battery packs. Three zippered compartments for radio, antenna, and accessories including spare battery pack Belt loops and detachable shoulder strap. Tough Dupont Cordura nylon. We are hams and we know you will like this case. Full refund guarantee. 12.50 includes shipping.

Compact Digital Cassette Drive for Low Cost Mass Storage

82161 Cassette Drive

THE HP 82161A Digital Cassette Drive (Fig. 1) is a portable, programmable, mass storage peripheral for the Hewlett-Packard Interface Loop (HP-IL).1 The storage medium is a removable minicassette that can store up to 128K bytes of information. Portability is achieved by the use of a four-cell nickel-cadmium battery pack, recharger, and power supply system similar to that used in other portable HP products. The 82161A is styled to fit in a family of compact peripheral devices such as the 82143A and 82162A Printer Plotters, and to fit nicely in a system controlled by an HP-41 Handheld Computer or an HP-75 Portable Computer, The 82181A makes use of much of the package design of the 82143A Printer Plotter,3 producing a unit 178 mtn wide by 133 mm deep by 57 mm high. Replacing the 82143A's printer mechanism on the top right side is a transport mechanism with a REWIND key and a door OPEN key located in front. To the left of these keys is the power switch and indicators POWER LOW BATTERY, and...

Testing Rechargeable Alkaline Batteriesand More

When we were first asked if the ARRL Lab could produce an article on rechargeable alkaline batteries, it looked so easy. We had previous testing experience with portable gel cells and lead-acid batteries and assumed the rechargeable alkaline products would follow nicely. For the most part, that turned out to be so. There were however, enough surprises, interesting results, and no small number of side roads in this project to provide good fodder for a QEX article. For a while it looked like the project was taking on the life of the Battery Bunny. (Or perhaps the cat with nine lives. Do you remember that frisky feline from late 50s TV commercial fame or are we dating ourselves a bit ) Here at last is the entire saga of the ARRL Lab's battery testing that kept going, and going, and Table 1 Typical Data for Rayovac Renewal Brand Rechargeable Batteries (Original Formulation) Table 1 Typical Data for Rayovac Renewal Brand Rechargeable Batteries (Original Formulation)

Easter In The Holyland

The peak of Ml, Tabor was crowned by a triband yagi and a station housed in a tern running off battery power. Here, 4X7T made close to 5.000 contacts under field-day-type conditions. Help from the nearby kibbutzim (collective farming villages) came in the form of food, accomodations and the charging of ihe lead-acid batteries used. The kit bitzirn Bet Keshet and Giv'ai Oz homes of the club stalions 4Z4SL and 4Z4SQ.

Convenient Top Controls

* Large LCD digital readout, Resdab e in direct sunlight l.v rtualfy no current dram) and in the dark ilamp switch). Shows receive and transmit frequencies and memory channel Arrow indicators show ON AIR MR* (memory recall), BATT (battery status), and 'LAMP switch on. Rubberized antenna with BNC connector, NiCd battery pack, AC charger, PTT and mic plugs, handstrap, and earphone included. PB-24 extra NrCd battery pack.

New Nls Touch Test

The 3Vz-digi1 Touch Test 20 measures 10 parameters and 20 functions and includes 44 ranges. Test parameters include ac and dc volts, ac and dc current. resistance, capacitance, temperature, continuity, conductance, and diode test. The package size is a smail 2.9 inches high by 6.4 inches wide by 8 inches deep. Weight is less than 3 pounds. Touch Test 20 may be purchased as a line powered unit or (optionally) comes equipped with rechargeable batteries for battery or line operation.

Other Radios And Accessories

XL156-EA Regency 10 channel scanner SALE . 129 95 UC102-EARegancyVHF2 cb.) Watt transceiver ,, 124.95 RH250B-EA Regency 10 ch. 25 Watt VHF trans. 329.95 RH800B-EA Regency 10 ch. 60 Watt VH F trans. 454.95 RU1 SO&-B.HRegency 10 channel UHFtransceiver, 449,95 P1405-EAflegency 5 amp regulated power supply 69.95 P1412-EA Regency 12 amp reg. power supply 164.95 MA256-EA Drop-in charger for HX10008, HX1200 . . 84 .95 MA257-EA Cigarette lighter cord (or HX1200 . 19.95 MA917-EA Ni-Cad battery pack for HX1200 , . 34.95 SMMX7Q00-EASVC. man. for MX7000& MX5000 19.95 SMMX3000-EA Service man. for Regency MX3OO0. . 19.95 B-4-EA 1.2 V AAA Ni-Cad batteries (set of four) . 59.95

The ARRL Experimenters Exchange

(2) A 12-volt battery pack and charger for emergency use. The battery is to consist of gelled-electrolyte cells (e.g., Gel Cells) sized to run a 10-W radio for about 8 hours (with an 80 squelched, 10 receive and 10 transmit duty cycle). The charger should be separate and operate from 115-V ac and fully charge the battery within

The Status of A Battery

The cost of a storage battery is, of course, many times less than that of such a filter would be. Ihis brings us to the trickle charger battery combinations, which, while not a battery substitute, do provide a reliable filament source from the alternating current line. The trickle charger is probably at present and likely to remain for some time the most satisfactory general purpose filament supply. The use of UX 199 tubes in series will, however, prove interesting to the experimenter and to the service man.

Interconnect Specialists

1990 Ham Radios

KA70SMns proposed system was very simple. The technology would be similar to that presently in use for animal tracking and research Only one or two frequencies would be needed. Transmitters would be low powered and pulsed al a low rate to conserve battery life and to allow multiple transmitters to be tracked simultaneously. Range would typically be one mile.

By Jack P Trautman and Lawrence A Des Jardin

The optional battery pack includes a rechargeable battery and charging circuitry to allow up to five hours of continuous portable measurements. For applications in the field, the 3468A and other battery-powered HP-IL devices can be set up to provide a completely portable measurement system. Electronic calibration. Complete calibration of the 3468A is done electronically- without anv internal man-

Quarter more current into the battery than is taken out

If the lamp burn brighter than usual, turn the battery around. From 32 volt farm lighting plants only one 24 volt B battery can be charged from one lamp. 48 volt B batteries must be charged half (12 cells) at a time. Use either a 10 watt or a 20 watt 32 volt lamp. A 10 watt lamp charges at .1 ampere -20 watt lamp charges at .2 ampere. From 110 volt power lines, one, two or three 34 volt batteries can be charged from one lamp by connecting them in series (positive ot one battery to the negative of the next). For one battery, 24 volts, use a 25 watt lamp. For two-batteries, 48 volts, use a 40 watt lamp. For three batteries, 72 volts, use a 60 watt lamp. The charging rate in each case will be about .2 ampere. A radio or automobile batteries can also be charged from direct current lines which include many small town and all farm lighting plants of 32, 65 and 110 -volts. The same hook up is used as on the B battery except more and larger wattage lamps...

Voltage with the test bridge

Avoid a reduction in bridge supply voltage resulting from the impedance of the battery in series with the supply. A rectifier-filter combination with a liigh-capacitance condenser in the filter output will obviate the need for the condenser as will also a storage battery, which usually has a high equivalent capacitance. The condenser should always be used with dry batteries.

American Reliance

Also new from Alinco is the DJ-100T 2 meter handheld tranceiv-er. It has 10 memories, LCD display, dip switch programmadl sub-tones, built-in converter, muF tiple battery packs, 16-butfon DTMF pad, BNC connector, and it has easily expandable frequency coverage. Price, 299. Write or calt Alinco Electronicst Inc.,

Packetradio Satellites Status Report

DO-17 transmits packets for approximately 2.5 minutes followed by an off period of approximately 30 seconds. As is true with each of the Microsats, the telemetry offers 59 telemetry points and the AMSAT Software Exchange has programs available that translate the data points into more easily recognizable information, ie, battery voltage, solar cell current, etc.

Vacuum Tube Principles

An electric current can be caused to flow through other media than a metallic conductor. One such medium is an ionized solution, such as the sulfuric acid electrolyte in a storage battery. This type of current flow is called electrolytic conduction. Further, it was shown at about the turn of the century that an electric current can be carried by a stream of free electrons in an evacuated chamber. The flow of a current in such a manner is said to take place by electronic conduction. The study of electron tubes (also called vacuum tubes, or valves) is actually the study of the control and use of electronic currents within an evacuated or partially evacuated chamber.

Hustler Announces New Tribano Beam Fixed Station Antenna

The Mark II is small enough to carry in your shirt pocket with aboul half of it sticking oul. It comes with crystals for 146.52 installed in channel A. It has six channels, A through F. There are separate receive and transmit crystals for each channel. Rejection of adjacent channel signals is excellent. The receive crystals must be netted along with the transmit crystals. There is a warning in the manual to avoid high rf fields, since they may cause damage to the receiver. The Mark II should not be used in close proximity to a base station antenna or closet than twenty Inches from another unit. Transmission without the antenna can cause damage to the transmitter. My 25 85 repeater is here at my house running 100 Watts out. but it hasn t hurt the HT yet. My Mark lit does an admirable job in this high-rf environment. The adjacent channel rejection it has is amazing, and you must do a good 30b of netting the receive crystals to get full performance. The Mark II uses a small 10,8 volt...

Indiana Quick Charge Qc Charger

When used with the supplied wall transformer, the charger typically supplies 300 mA to the battery pack, gradually tapering down to 40 mA In about 4 hours, Extensive filtering of the charging current will allow normal operation with most equipment while the charging unit is In operation When used with the mobile cigarette-lighter cord, the charging unit will allow operation of the user's radio equip ment while in motion. Models are in stock for most popular hand-held units and the GC500 is readily adaptable to virtually an nicad-powered device with a 4- to 9-ceil battery pack.

Edi Ted By Linoa Reneau Kaukm

Byonics Balloon Telemetry Ideas

1-watt. 2-meter FM beacon on 144 34 MHz, sending down a tone sequence indicating altitude, in out temperatures, and battery voltage. Unfortunately, a small hole developed in the balloon just before liftoff which caused ft to rip apart at 2600 feet. After a brief five-minute flight, the payload landed in woods 2.5 miles away and was recovered by the chase team-At least now the chase team has a successful recovery lo their credit. They plan another flight to 100,000 feet in about six weeks.

Communications Batterjes

Exact Replacement Packs Vaesu FNB2 Wilson BP4 522.95, Santec 142 1200(3 pin) 23 95 Commercial Packs-All Types Call Replacement Battery Inserts tCOM BP2 CM2 18 95. BP3 CM3 16 95. BP5 CM5 24.95, BP7 BP9 Rap 29.95 Kenwood PB21 S13 95, P824 321 95, PB25 25H 26 25 95r Azden 300 21.95, Standard BP1 C118 Pace MX-BT2 25.95, Tempo ST 270 23.95. S1H2,4,5, 450 23.95, S15 24 95f Yaesu FNB9 14.95, FNfB4 4A 33 95. Ten Tec 2991 24.95 Sanlec KTBP SI8.95 KTBP2 23.95. KTBPH 24 95, Rebuilding Add 4 to tnsed price for factory rebuilding, or send pack gr quote S A S E catalog. tnPA aod M C VISA add S2 order.

By Lewis W Masters Karl M Blankenship and Michael J Ward

The 5315A B is a moderately priced universal counter that accepts signals from dc to 100 MHz on both input channels. Its basic time interval resolution is 100 nanoseconds, but this may be improved on repetitive signals to less than a nanosecond through the use of averaging. The 5315A (Fig. 1) comes in a rugged plastic case that is suitable for bench use and can be equipped with an optional internal battery pack for portable and field applications. The 5315B is the same instrument housed in a standard HP metal package. The 5315B is useful for system applications or where superior EMI (electromagnetic interference) performance is required. Either instrument may be ordered with a temperature-compensated oscillator for applications where higher accuracy is necessary.

Low Cost Graphics Terminal

An optional battery pack provides 8 hours operation on an overnight charging. Batteries also charge when the Model 283 is used on a 110 V ac line. The B&K PRECISION multimeter weighs 3 pounds and measures only 9 x 7 k 3.6 inches. With battery pack, its weight is 6 pounds The Model 2S3 and accessories jre available from B&K-PREClSiON distributors.

The Bears Hunt the

The Fox Team was given a 15-minute head stan. They used a dual-band HT for 2 meters and 220 MHz and a variety of antennas, from stubby ducks to a full-waver They also had extra battery packs. The BEARS maintain the local 224.32 MHz repeater, so we were able to use 220 MHz as a backup and to coordinate events behind the scenes in case any problem cropped tip. The 224,32 repeater has an autopatch, so we would be able to contact parents or emergency services if necessary.

An Eight Digit Mainframe for the Measuring System

Model 5300B, a new eight-digit mainframe for the 5300 Measuring System, is compatible with all eight 5300-serles timer, counter, and multimeter snap-on modules, and with all three in-between modules including the battery pack. It was developed in response to the needs of many users for more resolution at a glance that Is, more digits in the display and more power supply capacity to handle existing snap-on modules under more severe environmental conditions and to allow more power for new modules, such as the 5305A 1100MHz Counter and the 5308A Universal Timer Counter.

Direct Current Amplifiers

In the circuit of Fig. 24 C, an increase in the B battery voltage does three things. It increases the B and the C voltages and also heats the filament hotter. If the various resistors are properly chosen, these three changes cancel each other and the d.c. balance remains constant. wherein the extra grid of the tube serves to compensate for changes in the plate, filament, and grid voltages when the battery voltage changes. 24.3 Multistage D.C. Amplifiers. It is also possible to amplify d.c. voltages with multistage amplifiers, as in Fig. 24 E. In the Loftin-White circuit of Fig. 24E(d), a common battery is used for the plate and grid voltages. The filaments of the two tubes are at different voltages and require care in insulation from the ground. In all multistage d.c. amplifiers, the voltage available for the power supply must be comparatively great.

Circle Ii On Reader Service Card

The Quantum Ham Battery may be the last rechargeable battery youll purchase. Its 12 volt 2.1 amp hour capacity packs up to six times the power of H-T nicad packs. A simple coiled cord connects Quantum's power to your H-T, If you buy another H-T just get another cord without the additional cost of new batteries and chargers. The Ham Battery wilf power all sorts of 12 volt gear past, present and future.

An Unprecedented Dsi Value

No longer do you have to settle for smalj readouts short battery life, a kit with a bag of parts, a black box with 20 Resistors that need adjustment every Ume you need to recalibrate, because you only budgeted 100.00 or 150.00 for a DMM. Resistor Networks to provide maximum accuracy, resuming in long time periods between recafibration and a simple two adjustment calibration procedure. The LC 5000 incorporates a fused input circuit to help prevent damage to the DMM. The large .5 inch LCD Readouts are easy to read even in the brightest sunlight and allows for very low battery drain, normally only two battery changes a year is required. The LC 5000 is the perfect lab quality instrument on the bench or in the field you can depend on DSI LC 5000 to meet all your needs. Buy Quality Buy Performance Buy Reliability Buy DSL

An Enhancement Mode PHEMTfor Single Supply Power Amplifiers

However, GaAs MESFETs (metal-semiconductor field effect transistors) or PHEMTs (pseudomorphic high-electron-mobility transistors) capable of meeting this need have also required an additional negative voltage supply for proper biasing. Alternatively, a manufacturer could choose a single-supply amplifier using silicon bipolar junction transistors, GaAs heterojunction bipolar transistors, or silicon MOSFETs (metal-oxide-semiconductor field effect transistors). These devices typically require a supply voltage around 4.8V, and to use them the manufacturer would have to raise the battery voltage or use a dc-to-de converter. All of these approaches have efficiency, size, complexity, or cost trade-offs that manufacturers would prefer not to accept if a better device technology were available.

Auto Charger For Cordless Soldering Iron

The increased portability is welcomed. Cordless soldering irons in themselves are great. What else are you going to use when soldering a connection at the top of a tower Everything has been tried, from a torch to a match, but expectedly a soldering iron works best. The only trouble is when you get to that remote repeater site and you suddenly remember that the iron is still in the shack where you plugged it in the flight before so it would get a good charge. For 4.95 you can get this adaptor that will let you keep that iron ready in the car where it be* tongs, of course) An overnight charge will restore dead batteries to a full charge with negligible drain on the automobile system. The -7585 Auto Charger Plug Assembly is available from What Clipper Corp 2902 Locust St., Sterling IL 67081

RF Technology Tradeoffs for Wireless Data Applications

The applications listed above are made possible through high-performance RF semiconductor components. These applications range in frequency front several hundred megahertz to C GHz and above and require several w atts of power output in some cases. These requirements need to be satisfied along with aggressive cost goals, achieved by means of low-cost, surface mount plastic packaging. The RF semiconductor technologies on which these components are based currently include gallium arsenide (GaAs) and silicon bipolar and will increasingly include CMOS in the future. Some specific examples of end-product benefits that RF component technologies can affect on a first-order basis include tiie cost, size, weight, and battery life of the wireless data terminal. Lower-weight systems have emerged because RF component manufacturers have been able to reduce their supply voltages, thus enabling operation from fewer battery cells. The battery is the heaviest component in many battery-powered...

Arrl Sanctioned Hamfest

The rechargeable buttery business is booming today, Willi the wideranging market in amateur radio and business-band portable transceivers HTs). the portable miniature cellular phone explosion* and now portable laptop and notebook computer systems, rechargeable batteries are found in many more areas of life than e er before, t' nderstanding something about these batteries and their technology has also become increasing ) important. so here's a hriei primer in eas Mo-understand terms. For decades, the only practical rechargeable batten was the lead-acid battery, primarily used in automobiles, boats and airplanes as a storage medium for electrica power. The vehicle's engine, when running, can drive a generator or alternator for recharging the lead-acid battery. Then, about 30 years ago, nickel-cadmium reehargeables came onto the scene and took up some of ilie market share for portable electronic devices of the time (larger wet NiCds were also used in stationary battery back-up...

Now You Can Have Your Packet

* Open Squelch DCD circuitry for faster more reiiable performance * Compact size * Attaches to your belt handie-talkie or handheld computer * Rugged construction wiih superb RF shielding (no birdies in your radio) * Standard battery pack provides over 12 hours o' operation * Advanced Personal MaiE Box & KISS mode included * 32 k-bytes of RAM * Complete with belt cfip, cables- battery pack & charger, comprehensive manuai * 30 day money-back One year warranty parts 8, labor

Superior Receiver Ano Transmitter Specifically Designed For Repeater Service


Practical Application Of The Cathoderay Oscillograph

The use of a biasing battery in the vertical or horizontal deflection plate circuit is quite in order. The battery is connected into the free deflection plate lead. However, this battery can be utilized only if direct connection to the plates is possible. If a blocking condenser is used in the circuit, the battery biasing arrangement cannot be employed. The amount of voltage required for the battery is dependent upon the amount of spot position shift desired. The battery voltage may be controlled with a potentiometer. The complete biasing voltage source in series with a 3.0 or 5.0 megohm resistor may be connected between the free deflecting plate and the ground plate. The signal voltage to be observed or applied across the same set of plates, then is applied to the cathode-ray tube in normal fashion. The high resistance in series with the battery serves to maintain the input impedance of the biased set of plates at a reasonably high value. The circuit which supplies the signal voltage...

Custom Microprocessor

The processor used in the earlier HP-71B Handheld Computer1 was an excellent starting point for the design this processor already met the low-power and interconnect requirements, but it would not run at 3V (the minimum battery voltage . By porting the design into the newer, smaller CMOSG process, the part price and the power supply requirements were reduced and the speed was increased. At the same time, new instructions were added to improve data manipulation and the interrupt structure was enhanced.

Printer Drive Circuits

To maintain a uniform print contrast, the thin-film head resistors must develop approximately the same temperature each time they are energized. The same temperature must be attainable even with changes in battery voltage. A constant resistor temperature profile requires an applied voltage with a constant rms value. The print intensity control, or power regulator, generates the required voltage by varying the duty cycle of a fixed frequency signal in a nonlinear manner in response to changes in the battery voltage (see Fig. 5). Generation of the signal is by analog computation. The duty cycle for constant rms value VRMS with battery voltage VB can be computed as follows. Fig. 6. Simplified diagram of the circuit that monitors the battery voltage and varies the duty cycle of the print signal to stabilize its energy content.

It Started With the CRT

Optional battery pack mounts entirely within oscilloscope with only two screws and one connector. No modification of scope's circuits are required battery can be added or removed at any time. Fig. 4. Optional battery pack mounts entirely within oscilloscope with only two screws and one connector. No modification of scope's circuits are required battery can be added or removed at any time.

Circle On Reaoer Service Card

These chargers are simply unregulated constant current supplies. On the other hand. Fast Charger is controlled by the Maxium Products MAX7I2 or MAX713 integrated circuits, allowing a fas* high current charge without damage to the batteries. The MAX712 part is used to recharge NiMH batteries. The MAX713 is used to recharge NiCd batteries. The only difference between the pans is the way the part detects the end of a fast charge cycle. The MAX712 detects the end of a fast charge cycle when the battery voltage plateaus the MAX713 detects the end of a fast charge cycle when the battery voltage starts to decline. When the MAX712 3 senses these output voltage behaviors, it automatically switches to trickle charge. Trickle charge is also reached when the MAX712 3 determines that a maximum expected recharge time interval has elapsed. The MAX chip contains circuitry that docs most of the work. A voltage regulator regulates the output voltage to recharge the batteries, a current-sensing...

Circle Ou Reader Service Card

SOLAR POWERED HA WIS The Sunswitch is a charge controller to protect your batteries iroim over charge. Power MOSFETs are used, no reJaysl Assembled tuned and tested. Now with Wall Mount Case, 55.00 plus 3.00 shipping, SUNLIGHT ENERGY SYSTEMS, 2225 Mayflower NW, Massillon OH 44647. SNB774

The NiCd Health Maintenance

* The NiCd Health and Fitness Center (Photo A) will let you pre-condition and recharge your battery packs correctly. It * The NiC d Personal Fitness Advisor will help you identify weak or aging cells w ithin a battery pack, so you can match like cells for maximum life or discard worn-out cells, Insert your batteries, set sw itch i SW1) to analyse and turn on the power The built-in voltmeter will show the battery voltage from 3.4 volts (.85 per cell) to 5.60 volts (1.4 per cell in ID steps. You can remove and use them, or you can decide to recondition them by either just charging them or discharging and then automatically recharging them. To charge yi ur batteries move SW i to Fast Charge and the charging IC will begin to charge the batteries m 250 mAt which is about one third of ihe capacity of AA NiCds called a C 3 charge rate). When the charge cycle is done (three to four hours) the H&FC will switch to a trickle charge mode (CY16). Notice that this trickle rate is much less than the...

Circle On Reaoer Service Caro

To help lame the tangled disorder of a temporary transceiver and amplifier setup within the family wagon, look no further than the junk box or the local Radio Shack store. It is possible to run a 12 volt lead directly from the automobile battery and terminate this run to an enclosure thar organizes the various 12 olt connection schemes. This will give ou a means to readily obtain power to suppl 12 volt DC to different types of ham gear.

Circle On Reader Service Carp

I don't want to write about NiCds anymore. As I've said before, the onty ones which have worked fairly well for me are those made by Sanyo. They seem to hold a charge much longer while sitting idle, and that may have something to do with it. Hopefully, the new nickel-metal-hydride cells or some other new kind of battery technology, such as the up-anti-com rng rechargeable lithium cells, will obsolete the old stuff once and for afL End of topic. Please.

All Oscilloscopes Include Probes

Ideal tgr fiefd lwnch appJicatrors ihis SCOpe can dispfyiy up lo T5 oiqnaLs interna battery pack Hows up r. 2 riourr. operation on a single charge Fc-tiurns ir.clufJi- h dl-Tfi baiiery Chflfger 5X h r vonljl magnihcfltlon tngh bnghlness CRT * 'ron( paT tj 1 rotator * hnicfi i iech, rgi-ijhie battery pack

Revolutionary Wiring Tool

The AD-1 comes with a four-pin microphone connector and a short length of coiled cable. Depending on the rig, it may be interfaced between the microphone and transceiver or hooked to an accessory socket. The push-to-talk method involves acoustical coupling. This is a bil more awkward, but involves no permanent connec-Irons other than a 12-volt supply An internal potentiometer allows user adjustment of the output level. If you are oniy interested in acoustical coupling, then the AD-lP might be a good choice. It is identical to the AD-1. except for the fact that it has only a speaker for output and contains a rechargeable battery.

To High Voltage Circuits

Continuous service at the peak voltage encountered, Just to play it safe use a capacitor rated for at least 200 v dc on a 115 v ac circuit, The rectifier P1V rating is a bit more involved so long as a battery is connected and drawing current the rectifier diodes are subjected only to potentials not much greater than the battery voltage. In other word5 the battery and the conducting diode (s) hold down the voltage across the non-conducting diode(s), The situation is drastically different if the charger is operated without load. Under this condition there is no current drawn, and the reverse voltage applied to the diode s may approach the peak of the ac iine voltage. So we have a situation rather the reverse of ihat usually encountered these circuits are not harmed by normal loads, and are not harmed by operating into a dead short-circuit, but if low-voltage rectifiers are used they can be ruined by being operated with no load, The solution is obvious either use high-voltage diodes or...

Standard New High Flying

Standard Communications, the world's largest manufacturer of VHF marine equipment, has developed a professional quality VHF FM 2 meter transceiver especially for amateur use. The 826 is so compact that it makes mobile installations practical in almost any airplane, boat or car, and it becomes fully portable with Standard's battery pack. When used in conjunction with the AC power accessory, it also makes an ideal, low cost base station unit. Enjoy the fun of amateur radio communication wherever you go for just 339.95.

Amp Model Circuit Breaker

After filling, let the cell sit for a while, and then top off with more electrolyte to replace that absorbed by the separators. Carefully wipe any spilled electrolyte from the polystyrene case. Charging of the small size cells, with a less than 25 Amp maximum discharge rate, can be readily done with the dc pqwer supply and battery charger whose circuit is shown in Fig, 1, If the supply is to be used only for battery charging, the filter capacitor can be omitted. Batteries can readily be assembled from individual cells by placing them in series. Room temperature open circuit voltage for charged cells is typically 1.86 volts. The normal voltage spread is such that six cells are used for a 9 volt battery, and 8 or 9 for a 12 volt battery. Charging current should be limited to between 7 and 10 of the rated cell discharge capacity. This value is generally found as part of the identification number printed on the cell. For example, a Yardney HR-5 series means that the cell is designed for...

Volt Transceiver Battery

Between one and two mA to flow through the zener. The input to comparator A is connected to the battery voltage keeping its output high and resetting the flip-flop. As long as the input to comparator B is higher than 3V both flip-flop inputs are high, and the output at pin 3 is low (ground). When the battery voltage drops below the threshold set by R1 and R2 (12V, in this case), comparator B output goes to ground setting the flip-flop and causing the output at pin 3 to go high. This output stage consists of two transistors in a totem pole configuration so that the device can supply high current as well as sinking current to ground. One of these transistors (only one) will be conducting at all times, and the chip is capable of supplying or sinking up to 200 mA. In this case it was found convenient to supply current to a load. The static current drain (light off) is about 12 mA. Since the battery voltage will show the biggest drop during transmit periods, the monitor should be connected...

Nickelcadmium Battery For Portable Fm

The nickei-cadmium battery pack described in this article was designed to match my two meter transceiver. This home brew project was undertaken to equip the transceiver for portable operalion in the field away from the car or ac power. The construction mainly involves cutting and bending sheet aluminum. The entire project can be completed in about three or four evenings. Photo 1, Bottom view of transceiver and nickel-cadmium battery pack. Photo 2. NickeJ-cadmium battery pack with front panel open to show individual cells in their plastic 4'egg crate ' Photo 3. Nickel-cadmium battery pack front panel showing 6-pin Jones receptacle and guide pin. supply with voltage and current meters can do a nice job of charging nickel-cadmium batteries. Or, a small battery charger could be built from available parts.

Volt Nickel Cadmium Battery

Alkaline storage battery sintered plate. Flat voltage curve during discharge. Will hold charge for long period of time. High discharge rate up to 50 amps, Stili-proof, may be used in any position. Approx. 6-ampere-hour capacity. Dimensions 6 high 2 wide l 2 thick. Approx. wt 6 oz. Uses potassium hydroxide (30 Electrolite).

Capacitance And Inductance

Mapping Equipotential Conductor Plates

Figure 3 B shows a source of electricity at E (the battery), connected by two metal wires to two metal plates, A and B. The two plates together with the insulating air between them, are called a condenser. Let Q be the amount of electricity on plate A, which is also equal numerically to the opposite charge on plate B. It is found that Q will be larger, and in direct proportion, if the battery voltage E is larger. This fact can be expressed by the equation Q CE, where C is a constant, called the capacitance of the condenser. Imagine a 3 Bj A sim

Linear And Nonlinear Circuit Elements

The circuit diagram of an audio frequency, double-ended Class B amplifier (Fig. 231) is the same as that of a push-pull amplifier. The C-battery voltage is adjusted so that the tubes operate at, or slightly above, cutoff. Sharp cutoff tubes are used. Figure 23 J shows the action taking place in tube number 1. This curve is redrawn in Fig. 23 K, together with a similar but inverted curve for tube 2.

Other Opteons You Think Of Some

Make the Box smaller and would probably run it a reasonable time, but you can find the D cells at just about any hardware store. Without the battery access panel, you have Io dig up a screwdriver and take it apart in order to change the batteries* This latter feature is designed to keep Junior from doing it himself Of course. you can customize this project to suit your wishes. If you want, you may use AA or even AAA batteries and expect reasonable life from the batteries thanks to the rela lively low current drain and lhe auto turn-off feature.

More Products

Recondition Battery Guide