[ARC5] Receiver Tube Substitution

[Richard Knoppow]

    I had assumed this was mistyping. I also said 6K8 but it is a 6L7, 
another noisy mixer.
    I have seen some seriously hacked Super-Pros. One had half the audio 
amp removed and a power supply tacked on the main chassis. Not 
restorable.  I did some experimenting with the RF stages on mine but all 
the modifications were done on plug in modules and I eventually restored 
the original circuit. I tried several different types of mixers and RF 
amps but found they made little difference, mostly for the worse. One 
mod that is worth wile is to add a 150V regulator to feed the plate of 
the oscillator and adding a TC cap across the oscillator section of the 
tuning cap. The TC cap was added by Hammarlund in the last model so its 
not really a mod. I used my BC-779 for SSB and did not have problems 
with low BFO injection, however, you can't run the RF gain at maximum.
>

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL