This is Realistic's TRC-47, an entry level mobile AM/SSB radio. It featured 23 channels, Volume, Squelch, R.F. Gain, a Clarifier which shifted both receiver AND transmit frequency, and an amber colored modulation indicator. This model radio first appeared on Radio Shack's shelves in 1974, as a lower cost SSB alternative to their TRC-46. By most accounts, this was a "bare bones" SSB radio, lacking even normally expected features such as an "S" meter, switchable noise limiters and PA functions. Performance wise, this radio was made to conform to the older power regulations and, as such, had some trouble making the full 12 watts out on SSB. Receive performance was about average, and the clarifier could be made to "slide" by the addition of an inductor in series with the variable capacitor. There were a few '47's around in the local area, including Steve, who owned 2 at different times, Inchy, and myself. This radio model ended its reign in 1977 when a new 40 channel model would replace it.
I picked up mine in the early part of 1976, from another kid in my tech school electronics class. I paid a whole $50 for it, which was cheap for the time. But there was a catch, the radio was broken. The transmit final had blown, and in the process of trying to repair it, the other kid replaced the final without insulating the transistor case from ground. This effectively shorted the collector B+ voltage to ground, which took out the blocking choke, and a couple of resistors. I cleaned up the mess, and replaced the final again, this time using the proper insulators. The radio came to life, putting out about 10 watts on SSB and about 5 on AM. But all was not rosy as the AM modulation was real low, barely making 20%. I also noticed that the receive audio volume was somewhat lower than expected as well, as I had to advance the volume to about half way for a normal listening level (Most radios did not require much more than 1/4 of the travel). While this was unusual (And in retrospect, should have been the major red flag), I didn't pay that much attention to it at the time. While trying to determine the cause of the low AM modulation, I must have tested or replaced almost every active part in the audio chain (Luckily I had the SAMs manual), with no luck. I finally conceded failure, and resigned myself to using this radio for SSB only (Where it worked fine), and switching to another radio for AM talking.
Eventually, I traded the '47 for a Midland 13-885, which had been nailed by a lightning strike. My friend Rob, who ended up with the TRC-47, took it to another guy who had a whole shop full of test equipment. He was able to determine that the audio/modulation output transformer had been damaged (Most likely from the B+ short to ground) and had shorted windings on the modulation side. He replaced the transformer and the radio was once again fully functional. Rob (Channel Master) used the radio in his mobile for some time after, although I don't remember exactly what finally happened to it.