Bnb

Tube-lype amplifiers, large or small speakers, mixers, microphones, tubes, parts, etc. Especially Western Electric. Jensen. Marantz. Macintosh, JBL etc, 1-800-251-5454. BNB202 mahlon loomis, inventor of radio by Thomas Appleby Q1967) Second printing available from johan k.v. svanholm n3rfr SVANHOLM RESEARCH LABORATORIES, P.O. Bo* 81 Washington DC 20044. Please send 525,00 donation with S5.00 tor S& H 8NB420 break the cooe barrier A sell hypnosis tape ihat...

Cci

WS MilLitonc Drive Bciwrcmk, Ohio 454-Vl MO Mill Ltt-djy rti vpLKJ .ir m Spectrum Analyzers - Spectrum Display Monitors Satellite Receivers - Signal Sweep Noise Generators AVCOM's new SDM-42A Spectrum Display Monitor is denned for use as a panoramic signa display for VHF seamen and corrriunication receivers such as the COM R-7000 The SDM-42A dispiays ad sign is present n the receiver's iF on a 5* CRT so that the operator can monitor signal activity The operator can then quiche tune to signals...

Electromagnetic Measuring Tool

New TriField* Broadband Meter combines a broadband field strength meter with an AC magnetic & electric field meter in a single package RF field strength setting (vertical, 10-1000 V m tOO KHz -2 5 GHz) is kaeal for making near-field transmitter measurement finding RFI on a tine, testing leaky microwave ovens or finding hidden surveillance 'dugs' AC magnetic setting (0 2 -100 mllligauss 60 Hz, range 50 Hz 100 KHz. full 3-axis magnitude) tests for magnetic interference (a sometimes nasty cut...

Hams Uiith Clrss

Carole Perry WB2MGP Media Mentors Inc. RO. Box 131646 Staten Island NY 10313-0006 Several gt ears ago Lvnn A. Brcece K4LFV, Li. Col, LSAF Ret. , contacted me after reading several articles about my work with young people in ham radio and about my involvement with the space program. Lynn began sending unusual and beautiful wall posters of the spice shuttles to our classroom One day, something really special arrived in the mail for the children. Our friend had meticulously collected and assembled...

Rep Repeater

A microprocessor-controlled repeater with full autopatch and many versatile dtmf control features at less than you might pay for s bare-bones repeater or controller alonel factory assembled stiil only 1295 50-54,143-174, 213-233, 420-475 MHz. MHz slitjhil Nsher. FCC type accepted for cofinnnercial scrvic in 150 S 4 amp 0 MHz bands Digital Voice Recorder Option, Allows message up to 20 sec. to be remotely recorded off the air. Play back at user request by DTMF command, or as a periodical voice...

Build an Audio Multiplexer for

Count CTCSS tones without expensive commercial equipment gt Roland Burgan KB8XI RR1, Box 43 Hancock Mt 49930 rburgan up.net Tired of struggling with low-end audio frequency counter readings, but mil ready to shell out money for an e pcnsi e audio prcscalcr Here's n much cheaper alternative. Obtaining an accurate reading of repealer CTCSS iContinuous Tone Coded Squelch System or tone-burst audio tones can be very difficult If the counter's gaic time is set to read out to 0. i Ha then usually the...

What

Lists all tiles net currently selected GB7LAN in Lancaster for forwarding via his Satgate. This prevents undue delays occurring in NA traffic. 1 also run a Satgaie, the second in the UK, and mail ts split between us. This is how the mail is split GB7I AN serves the following ureas only North America NA NOAM Central American countries CEAM Caribbean area CARB South America S A SOAM and parts of Europe via REQSAT server only Iceland, Norway, Finland, Sweden, Denmark, Germany, Netherlands,...

Vaesu

Modifications exclusively for Yaesu equipmem and also shows the user how to set up a system. It comes complete with a disk and is a good value for ihe money in the UK. I don't know if it is available in ihe US, bui it would make a very nice present for any ham. One of my HF forwardees. who visited me m the late 1980s prior to setting up his own BBS in Moscow, is I eo Labutin UA3CR. I forward every day with Leo, and have a very reliable path to him. In Norfolk, UK, we have a yearly event on the...

Dspzx

Excellence in digital signal processing, Jim Kocsis WA9PYH 2217 Hidden Oaks Ct. South Bend IN 46628 Timewave Technology, Inc.'s new DSP-599ZX is an audio digital signal processor DSPi made to improve communications in many different modes by reducing noise and interference. It uses an A-to-D converter to digitize the incoming audio signal, runs the digitized data through software algorithms to eliminate all hut the desired signals, and then outputs the remaining digital data through a D-lo-A...

Like It Should

John Pivnichny N2DCH 3824 Pembrooke Lane Vestal NY 13650 NearU every receiver, transmitter, transceiver, or transverter contains at least one mixer, yet this is one of the least understood circuits and you will need to know about iheir operation it you want to build ham equipment, if you ask an old-timer how the mixer works, you ll probably get something about sum and difference frequencies, But what about the signal levels What should the gt be Hou can you...

Supporting Delta Loop

Delta Loop

So simple and perfect for apartment dwellers. Thomas M. Hart AD1B 54 Hermaine Ave. Dedham MA 02026 While sitting on the couch, reading the newspaper, and listening to some local 2m repealers on my handie-talkie, I decided my signal needed some additional punch. The handie-talkie with three-inch antenna was not producing anything near the desired dead full quieting on certain local machines when it was my turn to comment Buy an amp Resurrect that 5 8-wavelength whip Both of these were unalluring...

Ham Vacation

Toma Yu1ab

A six-week journey through Yugoslavia. George Pataki WB2AQC 84-47 Kendrick Place Jamaica NY 11432 In the summer of 1996, I visited man amateurs in Hungary and Yugoslav ia. I was ahle to sec many radio dubs and personal stations, w here 1 noticed the large number of YLs and XYLv as well as youngsters, participating in the hobby. Family Lies in eastern Europe may he stronger than those in the West. This can be attributed to tradition and education, and perhaps to the fact that there are fewer...

Info

And cutouts for knobs let you use it without taking it out of pouch. Fully-adjustabie webbed fabric carrying strap has snap hooks on both ends. Wear around waist or over shoulder Keep your analyzer safe and looking new MFJ-29, 19.95, no window or cutouts. MFJ-208 MFJ-208 2 Meter VHF 7 Q SWR Analyzer finds the SWR of any antenna from 38-156 MHz. Jack for external frequency counter. 7l x2l 2x2L 4 inches. For Commercial VHF Radio Same as MFJ-208 but for commercial VHF, MFJ-217, S79.95, covers...

Tm

Revolutionary new SWR Analyzer is the best investment you'll ever make Now you tan diagnose a wide range of antenna problems instantly with one easv-to-use instrument. MFJ-249 MFJ-249 HF VHF 2 1 ft SWR Analyzer- has all the features of MFJ-259 but less RF resistance meter. Includes 1.8-170 MHz continuous coverage, 10-digit LCD frequency counter and smooth vernier tuning. MET-209 MFJ-209 HF VHF S1 AQSS Analyzer is iU same as MFJ-259 without LCD frequency counter and RF resistance meter Has jack...

Free Constructors Catalog

T gt PnCF i mCt-UftF. bV fti.UTE S ifiTW i 'a - com. u ti . canada amp mexico b - fwr at wckhlcj MUKJ MFNi'LiN ftDt-UH DISCOUNT qhdehs jdq-634-345 fax 800-s51-2749 offjce 702-565-3j c fax 7qz-565-49 b tMC 21 Cc lYAFEJC eKDERSOfc hJ. b qhdehs jdq-634-345 fax 800-s51-2749 offjce 702-565-3j c fax 7qz-565-49 b tMC 21 Cc lYAFEJC eKDERSOfc hJ. b

TVVCR Tuner Applications

Part Two of three you may want to keep Part One, from last month s 73, handy. Hugh Wells W6WTU 1411 18th Street Manhattan Beach CA 90266-4025 Voltages developed for use with tuners must he regulated and heavily filtered to reducc noise and voltage variations. Noise and voltage variations can cause tuner frequency instability, since tuners are voltage-operated de ices. Regulators such us the 7S 2 and LM317 work well in tuner power supplies. The mixer and hand control circuits operate on 12...

Build a Half Square DX Antenna

Antenna Half Square

And it sure works f William Van TUburg KG8AN 5198 West Valley Circle Portage MJ 49002-1932 Fig. 2, Feeding ihe cable and wire through the pre-drilled holes will iock ii in place with nothing but the force of friction. The half-square antenna is a gain antenna, yet it is one of the easi-_ est, quickest types of antennas to build. This half-square configuration is a DX antenna that on 10m starts picking up signals from about 500 hundred miles out and gets...

Home Brew Transistor Diode Tester

Not just blinking lights and weird noises . Henry L Bowman Rt. Box A-190 Parsons TN 38363 Although Tm not a radio amateur, I enjoy reading each new issue of 73 Amateur Radio Today. Unlike other electronic magazines, which offer construction projects with silly blinking lights and weird noises. 7_i provides useful projects that are well worth the time and effort to build. I buiit J. Frank Brumbaugh's Capacity Meter March 1996 and have found il to be one of my most useful lest sets. I have always...

Voltmeter

Using a tunable filter ahead of an RF voltmeter convenience, an optional DPDT slide switch can he added to bypass the 11 iter Mount the whole thing in a small 3 x 2 x 1.5 aluminum box, using BNC connectors for input and output. You can mark frequency calibrations on the tunable filter dial by using a calibrated signal generator Feed a known frequency into the fitter and connect its output to the RF voltmeter. Tune the filler for maximum output and mark the frequency on the dial. Continue...