Radio Amateur 10-1961

Field Strength Meter Circuit Diagram

Save those transformers from old rotor control units. You'll find uses for them. One is a transistor power supply- With a bridge rectifier, you can get 30 volts plus at more than 30 ma. plus. , . . K0VQY UHF TV is gone for a lot of areas. There are UHF converters and probably old TV boosters also. A majority of these contain a transformer that delivers 6-3 volts and 125 volts at 30 ma-, that is isolated from the line. Preamps, bias supplies, small set supply and a load of test gear you can...

Cityzonestate

1 t I I I I 1 I I I I I I I I 1 I I I I I I A Versatile Automatic Keyer From Surplus Numerous amateur applications exist for an automatic CW keyer that will, on activation, send a predetermined transmission at a preset rate of speed. Just such a device was developed for use aboard military aircraft and was designed to automatically transmit a distress message from the normal aircraft transmitter. The complete equipment is nomen-clatured Control Keyer Group, AN ARA-26, and consists of Keyer,...

Cornelldubilier

CORNElL DLiaiUER ELECTRONICS, DIV OF FEDERAL PACIFIC ELECTRIC CO., 118 E. JONES ST., FUQUAY SPRINGS. N. C. 920v from our transformers we were only able to get approximately 870 volts, In order to attain sufficient secondary voltage it wfas necessary to use a spare 12,6 volt winding on the filament transformer Tl as a line boost transformer in the primary of our plate transformer. The bias voltage is secured from transformer Ti- which is a filament transformer hooked up backwards and securing...

Oscilloscope

5 PUSH PULL OSCILLOSCOPE 425 Kit 44.95 Wired 79,35 TESTER 666 Kit 69.95 Wired 109.95 EICO, 3300 N. Blvd., LLC, 1, N, Y, Send free Catalog amp name of Name neighborhood distributor. 1 Send free Short Course for Ariiirpct Novice License 1 Send 7 oaress 36-page STEREO HI-FI GUIDE 25c enclosed for postage City ENGINEERS Excellent career opportunities in creative electronics design. Write to the Chief Engineer. c o Ampere Electronic Corporation Hicksville New York HOW would you like to raise the...

Tickler Winding

It's a physical impossibility at the current state of the art. Characteristics of the best available resonators include these extremely high Q suitable impedance level for the circuits resonant fieqaeney which is not affected by time, temperature, or other uncontrollable variables and lack of undesired resonances. Since everything connected to the resonator becomes, in effect, part of the resonator also, we must keep the resonator as isolated as possible from the rest of the circuit. This means...

Attach This Couponi To Your Order For Shipment Via St Class Mail At No Extra Cost

TERMS All items subject 1o prior sole and changc of price without notice. Ail crystol orders must b accompanied by check, cash or M O. wiih PAYMENT IN FULL. Dept. G 101, variations, mention must be made of General Electrics Lighthouse Larry ' who helped pioneer the rebirth of the High-C Colpitis by using it as the VFO in his popular 150-watt single-band contest transmitter. Since the GE circuit is similar to the three discussed here, we haven't shown it separately. We said earlier that...

Contact Your Distributor Or Gam Direct

As frequently installed in mobile and fixed station , Would you like to improve the sensitivity and the stability of your receiver If you would, and don't mind delving underneath the chassis a bit, one of the quickest routes is to modify front-end circuitry. The technical article, Up Front ' in our March issue contained a rather complete collection of improved front-end circuits. However, here's one which escaped attention when the article was prepared and which has escaped almost everyone's...

Heliwhip Antennas

Mark HELiWHIP Plastic Covered Fibre Glass Antennas noticeably improve mobile communications over long whips and base loaded antennas Mark Mobile's exclusive Static Sheath plastic covering reduces precipitation static improves reception signal noise ratio up to OB High radiation efficiency. Broadband with excellent VSWR-Mark HELIWHIPS are available in 4' to 8' lengths depending upon frequency, with models for all hands, 6 through 160 2 meters with CVS-2144, 2.5DB gain H wave whip. 50 ohm...

Specialists En Compact Antennas

A block diagram of this breakdown is shown in 1. To examine it more closely, let's The amplifier is actually the heart of the oscillator, for without it, the circuit could not function. However, it is just a conventional amplifier circuit, regardless of the overall circuit complications- Only two design choices are possible so far as thv amplifier is concerned i may be operated in Class A for maximum frequency stability due to minimum harmonic output, or it may be operated Class C for...

R W Elect Ronics

2430 S, Michigan Avenue Dept. 73 Phone CAIumet 5-1281 Chicago 16, Illinois General Coverage BC 34mc Bandspread on Amateur Bands General Coverage BC 34mc Bandspread on Amateur Bands 1125 MICHIGAN ST. MICHIGAN CITY INDIANA ,HAM HEADQUARTERS, U S A 1 Last month, we explored the field of crystal > oscillators in some detail, and promised you a similar study of VFO circuits in a later article. This is it. Almost every ham who graduates from the Novice license looks forward to the day when he is...

Laboratories

Entire tuning operation the input signal should be constantly monitored to keep the grid current just at zero grid current. Typical operating conditions for maximum power output with good linearity when the amplifier is driven by an exciter that is 100 modulated with a sine wave signal is as follows AVG Load Power Output * ,90 watts Peak Load Power Output 360 watts Power Gain 15.6 db Id O ma lc2 26 ma Ib 412 ma It zero signal 150 ma As an AM linear amplifier satisfactory operation in the 50-54...

For Your Heath

170.00 DX-35 200.00 DX4 280.00 DX-100 330.00 TX-1 'For original Factory-wired equipment, delivered here in good operating condition, toward a new GSB-100. For others, regardless of make, model, and condition, 1 will still allow you a lot more than it's worth I Here's my 10 deposit (returnable at any time) to reserve a Gonset GSB-100, so I won't be disappointed. What is your extra-high allowance for the gear J describe on the attached sheet Fred Haines W2RWJ 123 Roberta Drive Liverpool* Hew...

Sosurplus Radio Conversion Manual Volume

This book give circuit diagrams, photos of most equipment, end rather good and complete conversion instruction for the following BO 221, BC-342, BC-312, amp C-348, BC 412, BC-645, BC-946 amp , SCR-274N 453A series receivers conversion to 10 meter receivers, SCR-274N 457A series transmitter conversion to VFO , 5CR-522 BC 624 and amp C-625 conversion to 2 meters , TBY to 10 and 6 meters, PE-103A, BC-1D6BA 1161A receiver to 2 meters, Surplus tube index, cross index of A N...

Art Coliins

Transmitter, removed from aircraft, channel auto-tune or manual. 2-I& .I Me. tor Ham Rig with 813 final. Output 60-100 W, CW or modulated. Cry -calibrated for VFO. Excellent Condition Only S33.37 RT91 ARC-2 TRANSCEIVER Airborne AM, CW, MCW, Output 40 W. fmput 500MW Freq. Ranfle 2000 to 9050 KC In oiflht channels Input 2G.5 volt DC* nd. hip. wt. 00 lbs., w eontrol All item* FOB Burbankf Califiuhfcct f* prior jffllfl. In Calif+ add 4Min. order 3.73* 509 No, Victory Blvd., Burbank, Coliff,...

Radio Communications To Get Ahead

This 6-volume pictured-text course covers the fundamentals and circuitry of radio communications. While it stresses fundamentals, it does not neglect the practical it puts these fundamental principles to work. You will be able to read schematics recognize circuits used in radio equipment. You will understand electricity and magnetism. Following the study of electricity, magnetism, circuit components, vacuum tubes, power supplies, oscillators and amplifiers- the various circuits are put to work...

Electronic Supply

In a previous issue of 73, transistor symbols were given. One important thing to add for newcomers to transistors who et mixed up on polar it v and ruin a unit or two is to remember this. The middle letter, i.e., NPN or PNP will tell you the polarity that goes to the collector, ne , or pos. . . . K0VQY Enough readers sent in votes for us to get a fairly vague idea of which article was held in least disdain. The Nuvistor converter article won, just as Nuvistor articles almost invariably win....

Radio Bookshop

1379 East 15th Street, Brooklyn 30r N. Y Enclosed is 9-95, Please send me one of your 3-D maps immediately, U.S. World- Name Address Please include at no charge with this order a one year (new) (renew) subscription to 73 starting with the issue. Send order to 73 Magazine, 1379 E. 15th St., A popular method of clickless, spark-free keying using a combination of clamp tube and VR tube is shown in Fig. 1, By going a step further and using an additional VR tube and a potentiometer one can obtain a...

Complete Meter Station

ARC-3 2-Meter Transmitter, uses 2 832 A's in final. Automatic tuning assembly, aligns itself automatically both transmitter and ARC-3 Receiver can be used on 2 Meters with hardly any changes. Complete with tubes* Just unpacked Transmitter 14,73 Receiver SI4.73 Both for 24 73 5 'Scope with 22 lubes such as 6SN7, 6SL7, & H6, etc. Compact easily converted for oscilloscope use or ponadapter. Complete with all tubes don't faintl a smashing 73 Special at only 5.73 100 WATTS ON 80, 40 & 20 813...

Ham Shack Novelty

Authentic-looking, two-color certificate claiming tongue' m-cheek ownership of an acre on the Moon's surface Ideal gift or conversation piece for shack, bar, den or office, (See Pg 119 Jan. 61. CQ.) With gold seal and name and call inscribed only 1,00 each* Six for 5t00+ Send check or M.O, BOX DXG, 1738 201 St Bayside 60, N. Y. vantages differs from project to project, but it's safest to use conventional sockets anywhere above about 7 mc. Your choice of transformers will probably be determined...

Ez Way Towers

Put your Tribander at 41' in 70 mph wind 135 mph cranked down to 24' . Tilfi over for E-Z access to array. Mounts Ham-M Rotor inside tower head. Top radial bushing - vertical thrust bearing. Safety rest locks gt tower at desired height. No weight on cables. E LA. R5-222 specs. Heavy wall structural steel tube legs, solid steel rod diagonal amp horizontal bracing arc welded, get J by Top Flight Distributors

Meter Band

B-20-6 K6CT Polarized Diversity Beam, 6 element. 1W O.D. Center Sections 1 O.D. A W O.D. adjustable end sections. Boom 2 O.D, 24' long, J25 .19 Spacing. Forward gain 12 D.B. Front Back ratio 44 44 lbs PREPAID SHIPMENT LL5.A.-DIRECT INQUIRIES TO 1076 E. WALNUT ST., PASADENA, CALIFORNIA been published in at least three different versions, They're shown as circuits A, B, and C in Fig. 8. While this circuit is definitely a two-terminal affair and so might be classed as a negative-resistance...

J J Glass Co

MAIN STREET LOS ANGELES 15, CALIF. Ham TV is no longer a complicated or expensive hobby- It is quite simple to pul a signal on I he air when you know what you are doing. This book tells you how. 1 fsed TV receivers are available very reasonable ihese days , . , find out how to convert these old sets for Ham TV, This book is light on Lheory, presenting just enough so you'll have a good idea of what you are doing. Ham TV is inexpensive and just about the most fun you can have in ham...

Designed For Halfton Antennas

We've designed our HAM-M antenna rotors to support a dead weight of 1000 lbs. Your antenna probably weighs a small fraction of that, so see for yourself the kind of safety margin the HAIVt-M gives you But there's more A positive electromechanical locking mechanism provides 3500 inch-pounds of resistance to the side thrust and whipping action of hurricane-force winds. And its bell-shaped, high tensile strength aluminum alloy housing is completely waterproof, assures brilliant performance even...

Ground Screw

Solved in the manner shown in the accompanying illustrations which are self explanatory-Parts readily available in the station junk box were used. Obviously, other parts of similar style may be substituted from what you may have on hand or purchased to suit the builder's taste. For example, the writer used an Ohmite Model 111-5, non-shorting power tap switch as it was available- Although this is a 5 point switch, only three taps were used as will be obvious from the accompanying illustration...

The V Audio Limiter Is Actually An Improved Clipper

It employs a triode with biased clipping diodes in its plate circuit. The clipped wave is applied back to the grid as inverse feedback to lower the distortion. A neon indicator begins to flash with 3 db of clipping. Additional clipping can be obtained by advancing the speech level control calibrated in db. 200V TRANSMITTER AUDIO LIMITER & INDICATOR CIRCUIT 200V TRANSMITTER AUDIO LIMITER & INDICATOR CIRCUIT HOW DO YOU ADJUST THE 200V AUDIO LIMITER Simply advance the speech level control...

Geareo Slow Motion Drive

For Amateur Radio amp Communications high grade assembly, flywheel loaded, manufactured to fine lolerances, provides a smoolh positive drive with a reduction ratio of 110 1. The vernier with its 100 divisions rotates 5 times for one pointer traverse, giving 500 divisions with positive reset readings. A cam adjustment on the vernier assures correct zero setting. A spring loaded jockey arm maintains tension of the pointer drive. Overall dimensions x 5W Stratto C o' l Id E ddystone 16.50 NET 1833...

Ham Microphone

Sharp Cutoff Below 300 and Above 3000 cps Minimizes Splatter, Reduces Unwanted Sideband. Klimination of resonant peaks permits higher average power more audio punch* Shaped frequency response Superb Intelligibility Naturalness of voice. Trouble-Free Controlled-Ma netic Design Hi-Output 52,5 db Extraordinarily Rugged No humidity problems. Complete with Crip-to Talk Switch* Desk Stand, 2-Conductor Shielded Cable. Will operate VOX and Grip-to-Talk. Complete with stand, grip-to-talk switch, 7 ft....

Miniaturized

New end loading principle to maintain effective radiation. No rente* laoding employed* Weight, H fbf. Light enough far TV Rotor. Feed line, RG5BAU or equiv. SWR. lest than 1,5 1. Model 8-24 Amateur Net 54,95 Write for fifora uro and fhe nernitf of your nemejt MINI-PRODUCTS diitnbutor T 0 01 West 18th Street Erie, Pennsylvania Patents Pending f )nler direct from factory or your favorite distributor. T 0 01 West 18th Street Erie, Pennsylvania Patents Pending f )nler direct from factory or your...

Craftromics

Santa Clara, California no output, no voltage is applied to the lamp. With no voltage, resistance drops from the balance value and the bridge is unbalanced. With the bridge unbalanced, feedback is reestablished an 1 oscillation resumes. It builds up until the bridge is balanced. With the bridge balanced . , - and off we go again. That's the picture theoretically. In practice, the thermal time constant of the lamp filament is long enough that operation settles down within a...

Day Trial After Purchase

We guarantee you must be satisfied with performance or you may return the equipment within 10 days for refund. guarantee your investment 90 days by our Same as New 90 day warranty on all parts. BONUS FEATURE Full 90 day return credit WRL offers a 90 day return privilege whereby you can trade back equipment for full credit subject to equipment not damaged) on any of our NEW equipment of higher value. All transactions F O B. WRL, WRITE FOR LATEST RECONDITIONED EQPT. LiSTf

Short Path

LOCAL TIME 00 01 02 03 04 05 06 07 08 09 O II 12 (3 4 15 16 17 18 19 20 21 22 23 LOCAL TIME 00 01 02 03 04 05 06 07 08 09 O II 12 (3 4 15 16 17 18 19 20 21 22 23 Howard S. Pyle W70E 3434 74th Avenue, S> E. Mercer Island, Washington A large number of hams prefer to use the same antenna for both transmission and reception- In the more advanced ham stations, such change-over is accomplished either by means of a relay of some magnetic type, often co-axial and of late, an 'electronic' type, vacuum...

Seco Tube Testers

GRID CIRCUIT AND TUBE MERIT TESTER ful J TV tu be coverage M odel 78 69,50 net COMPLETE TUBE TESTER tests Dynamic Mutual Conductance, Cathode Emission and Tube Merit rrcludes Grid Circuit Test MODEL 107 139.50 net Mode J 500 wired and factor, tested 29.95 Net Mode J 500 wired and factor, tested 29.95 Net Complete with all necessary cables a nd adaptors rVTodef 510- 46.95 Net Complete with all necessary cables a nd adaptors rVTodef 510- 46.95 Net Comp, with instructions Model 520 42.95 Net Comp,...

New Power Converter

TYPE C650E FOR 6VDC INPUT t35 12VDC to 250VDC uj) to 150MA TYP CI225E 30 C625E f r 6VDC nnut 30 Lvrce JVflviW Charger 5yir mi St LT A ft Silicon R eMfi r Direct Replacement Hon-Aging Hermetically Seated SELENIUM F.W. BRIDGE RECTIFIERS DC I8VAC 36V AC 72V AC 30V AC AMP 4VDC 2BVDC 54VDC I00VDC with order F.O.B. New York. Ten day fuarantee, price of mibe, only. Our J7th year, Vices jhow > oro rbjecf lo change,. 111KJ Liberty St., N. Y. 6t N. Y. RE 2-6245

Amateur Types

Frequency Ranges in Kcs. 3.500 to 4.000 (80M) 7.000 to 7,425 (40M) 8,000 to 8.222 (2M) 8.334 to 9,000 (6M). Rugged. Low drift, fundamental oscillators. High activity and power output. Stands up under maximum crystal currents. Stable, long-lasting 500 Net (All Z-2 Crystals calibrated with a load of 32 mmfd.) Hermetically sealed calibrated 2-1,000 t 24,666 and 25,000 to 27,000 Kc., 3 Kc. .050 Net direct v in 6-meter hand tier-to 54 iic., 15 Kc. .050 pins. Fifth overtone tor operating metically...