Realistic (Radio Shack) TRC-409 Portable Citizens Band Radio
Cool Product Report

It has been a long time since I've had a citizens band (CB) radio in my car. Back in the 1970s when the CB craze was at its peak, with songs like C.W. McCall's "Convoy"* topping Casey Kasem's American Top 40 (AT40) charts, my high school compadres were all installing 23-channel CBs (standard at the time) in their cars and pickups. I joined in with a Radio Shack unit (don't recall the model number). In those days the FCC required operators to register and mail a check for a few bucks - same with radio control (R/C) systems for model airplanes also operating in the same 26-27 MHz radio band - in return for a "Citizens Radio Station License" document to carry in your wallet. Most CB channels were spaced at 10 kHz, but the R/C frequencies were in−between some CB channels spaced at 20 kHz. For instance, my 3-channel OS Digitron R/C system was at 27.195 MHz, which resided between CB channels 19 (27.185 MHz) and 20 (27.205 MHz). Some electronically savvy CBers would illegally modify their radios to include operation on those in−between frequencies (e.g. Ch 19A at 27.195 MHz), thereby creating a scenario where merely keying up the transmitter could "shoot down" a model airplane if close enough.

Here are some photos of my late 1980s vintage Archer (Radio Shack) model TRC−409 portable CB (40 channels). It is in like-new condition since it rarely got used. I also scanned and posted the user's manual below for the benefit of anyone looking for one. I see the TRC-409's for sale on eBay sometimes without the manual. People like to bash Radio Shack, but I got a lot of good stuff there over the years when ordering online was not an option.

You can see there are no integrated circuits in the RF and analog sections, with just a single IC for driving the LED display. I could not find a schematic for the TRC−409, but it looks from the back side of the PCB that there is no other DIP footprint that would indicate another IC. The large potted section appears to be the PLL circuit, where the bottom layer of the PCB being a ground plane.

At some point I'll post my Realistic TRC-474 40-channel CB radio stuff.

Realistic TRC-409 Portable CB Radio User's Manual 

*If you've never listened intently enough to pick up all the words, you can read the lyrics here... "Well, we shot the line and we went for broke With a thousand screaming trucks, and eleven long-haired friends of Jesus in a chartreuse microbus."

Posted February 4, 2021