WA7KGX Ham Radio Blog

This counter needs a clean RF signal to get an accurate count. A bit of pink wire inside the shielded SWR sensor gets enough RF to run the counter.

Interfacing the Racal 1992 Counter with GPIB
E. F. Johnson Viking Ranger 160-10 meter CW/AM Transmitter
LEDs and Smarts for the CDE/Hy-Gain Rotator Controller
MODS for the MFJ-931 Artificial Ground
Rubidium Frequency Standard and GPS Disciplined Oscillator
New Life for my BUD (Big Ugly Dish)
Slower Speed CW (QRS)

Radio Daze -- Memories

My first memories of radio involve a ham who lived across the street. He had his station in the attic of his parents' house. He could send code across the country. He could light a light bulb by placing it near the transmitter's tank circuit. That was incredible. I remember looking through a catalog and picking out a microphone for his transmitter. I don't know if he ever got that microphone, or if it would have worked with his station. I was about four then.

In early grade school I built a crystal radio from a kit and tuned in the local stations. I also had one of those rocket ship crystal radios.

By 6th or 7th grade I was converting old radios into transmitters by connecting the oscillator section of the tuning condenser to an antenna and applying audio to the cap of the 6A8 converter tube. An old radio with shortwave bands allowed me to listen to Radio Australia on 9580 in the mornings. I took over my folks' big Zenith console radio before I got into Hi-Fi. This radio had a 78 rpm changer, two 12 inch woofers and a treble speaker, biamped. I played LPs with a Columbia turntable with a pull-out tonearm. Back then Hi-Fi meant being able to play an entire side without the needle getting stuck.

By high school I had a Miracord changer, Eico 20 watt amp (built from the kit) and an Acoustic Research AR2 speaker. The Eico had trmendous bass response - I once connected a speaker to the phono input and another small speaker to the output. When I wiggled the input speaker, the output speaker would wiggle in response until its little magnet was demagnetized.

My high school broadcasting adventures are chronicled under Radio Free Moscow.

I made 6 meter transceivers out of some old tube type car radios and a few extra parts. The receiver used a super-regenerative detector which became a modulated oscillator for transmit. The pair of radios could communicate over a half mile using standard car antennas.

During high school I passed the code and got novice and technician licenses. I dumped my old W9SEX and W9QRM calls for WA9JGQ.

I converted a surplus VHF business band transmitter down to two meters, adding paper clips to the final tuned transmission line to obtain resonance in the two meter ham band. A turret type TV tuner was modified to convert two meters to HF. I shortened the elements on a channel 2 Yagi to make a wide spaced two meter beam. A Heathkit 55 watt hi-fi amp provided modulated B+ for the transmitter. A KnightKit R-100 receiver and Ameco Nuvistor 2m converter kit listened on two meters. There wasn't much 2 meter activity in the Wisconsin Northwoods back then, but I did manage to eke out a contact with a ham in Appleton, 110 miles away. The signals were very weak, and we could not identify each other. Some years later, both of use were studying electrical engineering at the University of Wisconsin, Madison. We found ourselves in the same circuits lab where we just happened to compare stories and determined that we had made that contact,

I studied a study manual for the FCC First Class Radiotelephone license my sophomore year in college. Over Thanksgiving vacation my roomates and I took all the FCC exams we could at the New York FCC office. This was the last chance to take these exams for free. Shortly afterwards my roomies received failure notices from the FCC, but I received nothing. Weeks later I received my First Class Radiotelephone license.

I got a job monitoring the transmitters at WISM and WISM-FM weekends using my FCC First Class Radiotelephone license.. Back then a First Phone had to be on duty to check the directional array antenna currents.

Over the summer I worked for WISC-TV substituting for engineers as they took their summer vacations. WISC-TV was the only VHF station in Madison. I built a TV camera from a kit and converted a military surplus TV transmitter to the 420 mHz ham band. I designed my own video modulator for this transmitter as the original modulator had a poor bandwidth. I also experimented with flying spot scanning using a small photovoltaic cell as detector.

The summer after graduation I worked at the Gisholt Machine company. I designed a silicon transistor servo amp that worked with a cheap motor to replace a $5000 unit with germanium transistors that required its own air conditioner. The heat test chamber was not hot enough to affect the new servo amp. The amp and motor were installed on a turret lathe. It worked perfectly for about a month, regulating the feed rate so precisely that the shavings were extraordinarily uniform. One afternoon the lathe was working on a 400 pound cylinder, taking an inch off the diameter and a 4 inch drill down the middle. The feed rate took off and the work piece came unchucked at 60 rpm, busting $200 worth of tooling and rolling across the floor. I had been asked to design a servo amp with one millivolt sensitivity but there was no mention it would be used in series with another servo system. The phase shift caused by connecting the two systems in series reduced the margin of stability to where the vibration caused by the aggressive metal cutting disrupted its operation. That taught me a lesson - don't just design to the specs you boss gives you. You must understand the entire system.

I married during graduate school and moved into an apartment. I built a cavity resonator out of a coffe can to pull out Chicago FM stations WFMT (98.7)and WEFM (99.5) in between strong local stations.

After moving to another apartment I built a 50 foot long Yagi antenna to receive Chicago's WFMT classical music station. It gave much better reception than a Radio Shack FM antenna, good enough to listen in FM multiplex stereo.

When I first started work at Tektronix I built a RTTY demodulator using a double peaked active filter and obsolete RTL logic parts. I developed an 1800/110 bps modem for Tek but it was not productized. I designed the vector generator and serial interface for the Tek T4002 graphics terminal. I was project engineer for the 4010, 4012, 4014, and 4081 terminals.

When I moved to a large houseboat in 1975 I dabbled in two meter FM and SSB.

I left Tektronix for a small company called Sidereal where I designed their early Micronet terminals. The first three models used a Motorola 6800 CPU. I designed boards for Telex, TWX/DDD, 1200 baud, BRPE paper tape, remote batch, CRT display, and floppy disk interface.

The river was not a good VHF location. I practiced code and passed the tests for an Advanced ham license. I got a Drake C line, Hustler vertical, Dentron amplifier, and some long wire tuners.

I gravitated to RTTY and made my own Terminal Unit from the Sidereal Micronet computers I had designed for work. I wrote my own terminal program called CTU (Chuck's Terminal Unit). The CTU program synced its idea of the time to the 60 kHz WWB signal using a background software phase locked loop. Much of the time CTU would operate on 3627.5 kHz autostart. Hams could address my station and get a RTTY distortion report. They could also forward a message to local two meter RTTY. That activity languished when I left Sidereal as the tools to support the CTU program were no longer available.

Memorable contacts include RTTY to Antartica and QRP to Alaska with a HW-7. I bought a Dentron MLA2500 linear amp primarily because the FCC was about to mandate removing the ten meter band from amps. I didn't use the amp much because the high power RF was more than my antennas could comfortably handle. The amp was useful on 10 meters to boost the Drake's anemic output to something reasonable.

I had an Eico 753 HF transceiver in my car for a brief time before it was stolen. I worked east coast on 75 and Japan on 20 mobile with the Eico.

I dabbled in VLF monitoring to detect solar flares using a strip chart recorder.

In 1995 I moved from the houseboat to Caddyshack. I miss the houseboat's metal roof which made a good counterpoise for verticals. I now monitor a number of VLF stations using Linux. I haven't been on the bands as much as before but my 30 year old Astron power supply and Butternut HF6V soldier on. My main rig is now an ICOM 756 Pro which recently blew its driver transistors. I also have a ladder fed multiband dipole and a Thunderbird TH5MK2 up 56 feet.

In April 2008 I fired up the 30 year old Micronet hardware, got a copy of Sidereal's old PDP-11 Unix running in my Linux server, and updated CTU for a Sidereal Reunion.

Caddyshack operating position with Supervisor. 756 Pro, 706mkiig, MFJ-993B tuner, Bendix MicroMatch, CDE rotor with Idiom controller, MFJ paddle, Yaesu HTs, office computer, Thunderbolt GPSDO. Homebrew audio interface can be seen under the 756 Pro. Astron RM-35M, RF Concepts rfc 2-317 2 meter amp/preamp. Not seen: ICOM R-9000 with replacement green CRT.

Below: Classic Astatic D-104 microphone bought at the Rickreall hamfest for $20. The original element was dead so I replaced it with a $2.99 Radio Shack electret element (270-0090). My junkbox contributed a few parts to interface the electret to the 756 Pro. I didn't have a spare four conductor mike cable, so I used an old S-video cable.
Some pictures of hy ham tower

ICBM N 45 35.689 W 122 52.420 Z 319'

160 Meter RFI from Panasonic Plasma TV as displayed by WSPR. The receiving antenna was about 130 feet from the TV. Signal to noise ratio improved 5 to 6 db when the Panasonic was turned off at 0558Z. This was taken on a summer evening when the natural noise level is high from numerous thunderstorms. The plasma TV would make more of a difference in winter when atmospheric noise is much lower.

Slide Show on VLF Monitoring for the May OTVARC Meeting (Powerpoint Translation)
Slide Show on WSPR and JT65 for the May OTVARC Meeting (Powerpoint Translation)

---

---

Part of Stan's incredible collection of Vintage Tektronix Scopes