This is the Cobra 139 XLR. This was Cobra's "middle of the road" AM/SSB base station. This was the 40 channel version of the popular 23 channel Cobra 139. Features included Volume, Squelch, R.F. and Mike Gain controls, and a new FCC mandated receive-only Clarifier. Also included were 2 large meters, with modulation and SWR measuring capability, as well as the standard S/R.F. functions. Rounding out the list of features was a switchable ANL/NB, and a P.A. function. While physically resembling the older 23 channel radio, electrically they were nothing alike. This radio was a "first generation" 40 channel radio, coming out in late 1977 or '78. As such, this radio, or more accurately the chassis in the radio, (The Uniden uPD858 PLL) was one of my all time favorites for capabilities and modifications. PLL mods could net over 200 channels out of this PLL and VCO combination. The mic preamp circuitry had speech compression, and audio filters which could be tailored to suit individual tastes. SSB power out could reach 20+ watts. The clarifier could be unlocked and easily made to move up and down 5 Khz, to fill in any gaps in coverage. Performance wise, this radio faired pretty well. Adjacent channel rejection was fairly good, as were most 40 channel designs. Transmit audio was great, the radio has enough audio gain that an amplified mike was not always necessary. The Noise blanker was somewhat effective, although newer designs like the Cobra 148/2000 (MB8719 PLL chassis) seemed to do a bit better. There were a few of these radios in the local area, though no one in any of my groups ever ran one. Although there were a few who ran the Radio Shack equivalent TRC 457/TRC 458.
The radio pictured was purchased for a very cheap price, as it was not working. As it turns out, the relay was missing. Not being able to find a direct replacement, (Parts for this chassis are very scarce these days) I "adapted" another style. The radio is 100% functional, and mostly stock except for an unlocked clarifier. On a scale of 1 to 10, this radio earns about a 8. While other radios have shown better performance in one area or another, the sheer capabilities of this radio made it a tech's dream and a lot of fun to experiment on.