[Boatanchors] Boatanchors Digest, Vol 71, Issue 39

[Drew P.]

Glen Zook wrote:

"That is what happens on most, but not all, of the transmitters designed for the 6146 or the 6146A/8298.  I have run into like 3 transmitters of exactly the same model and with serial numbers within 10 of each other in which 1 of the transmitters worked fine with the 6146B/8298A and the other 2 were VERY unhappy!  Probably, the component tolerances added up "just right" on the transmitter that worked fine with the 6146B/8298A."

It would be interesting to perform an analysis to determine the cause behind 6146B instability.  ISTR seeing some designs a while back which neutralized 6146B's operating in the VHF Low Band by using a trimmer cap in the screen lead, thus forming a series resonant circuit to ground with the lead inductance.  Possibly there is some difference in the screening to account for the malperformance of 6146B and friends in radios not originally designed to accommodate them. Perhaps modification to screen bypassing would tame such cases.

Drew