Description
After many years of searching for an NOS (New Old Stock) 6G8G tube as a reliable spare for my AWA 500 series receivers, I've finally found one....with the help of AI !
I have to tell you now....without the help of AI I don't think I would have ever found it ! They only had one left in stock, so I guess I got it ''just in time''.
This multi-role tube acts as a demodulator, an automatic gain control tube (AGC), an IF amplifier, and an audio driver, which drives the 6V6GT audio output tube, so it's a very versatile tube !
FINALLY: It IS possible to replace the 6G8G with a 6B8G tube and the radio will still work, but with some reduction in performance.. Also, if a 6B8G is used, realignment of the IF transformers is recommended.
It should be noted that this receiver (the 500 MY) does NOT employ a separate RF amplifier stage, and as a consequence, the sensitivity on reception is only in the vicinity of 10 to 50 μV.
As a comparison, a well designed communications receiver of that era had a much improved sensitivity of around 1 to 5 μV. (microvolts) due to the addition of a separate Radio Frequency Amplifier stage.
If you're located a long distance from the transmitter(s), the poor sensitivity of this receiver will result in ''background noise'' when you attempt to tune in the station....or...you may not even be able to hear the station !