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Direct mp3 download or play: Ham Jammers Early 1980s # 1
In the late 1970s and early 1980s, I became interested in receiving and recording different types of radio communications. One of the first radios I used was the Realistic Patrolman 4. I thought it was pretty good, because it even had a squelch control. I remember listening to the Contra Costa County Sheriff, Martinez Police, (155.880 MHz before they went to UHF) BART trains, and early mobile phones, (when they were analog and on VHF) and several paging companies. Unfortunately the reception was not good, because the selectivity on the VHF low and high bands is so wide that many signals overlap and become unlistenable.
The one exception was a very strong signal at 146.820 MHz. In addition there were no other strong signals near this frequency. The reception on 146.820 MHz was as good as listening to an FM broadcast channel like KPFA at 94.1 MHz. By the way, at my house in Martinez, California, there were only three VHF signals on my Patrolman 4 radio that were consistently good. Those would have KDFM in Walnut Creek at 92.1 MHz, KPFA in Berkeley, and an amateur radio repeater at 146.820 MHz. I later found out that the amateur station was located in the Berkeley Hills like KPFA, which is probably why the reception was so strong.
I listened to the amateur station regularly, and at first it seemed quite normal. The more I listened, the stranger it became. There was lots of joking, cursing, and playing recordings of other radio operators. They kept referring to “jamming.” This, of course, is the act of an operator deliberately transmitting or keying up their radio while someone else is talking. This would cause the conversation to become garbled, distorted, or completely blocked, depending on how strong the jamming signal was being received by the booster station or repeater. A repeater is actually a receiver and a transmitter working as one. In the case of this one, the amateur operators would transmit on 146.22 MHz, and the repeater would receive these signals and broadcast out at higher power on 146.82 MHz.
As you may have noticed, there is a difference of 600 KHz between what is known as the input and the output of a repeater. 600 KHz is a standard amount of separation for amateur repeaters, and is widely used throughout the United States. I decided to start recording this amateur station on a regular basis. I took the signal from the headphone jack on the Patrolman 4, (a10 ohm resistor across the output to simulate a load instead of headphones) and fed that into the line input on a Shure M67 mixer and then connected the output to the line in on my Superscope C-104 cassette recorder. This setup allowed a VU meter to monitor the recording.
Once I started recording these ham radio operators, known as “jammers,” I knew I was hooked. I regularly listened and recorded for years, and much of the stuff I got was absolutely outrageous. Negativland ultimately incorporated some of this material into their releases. “Jamcon84” and “A Big 10-8 Place” are notable examples of the use of ham radio jammers. There is a website here that appears to be where ham radio operators can talk about the times they had in the early 1980s, talking on the 146.82 repeater and more. There is also a ham radio club in the Los Angeles area, with a similar spirit to the group in the Bay Area. They have streaming audio of their repeater, and you can go here and here for more info. Go here to hear 147.435 live. Just one last thing, “amateur” and “ham” operators (as far as I know) are one in the same, with emphasis on the “ham” in the case of these guys.
Radio Shack Realistic Patrolman 4 multi-band receiver
Shure M67 Mixer
Superscope C-104 cassette recorder