[R-390] R-388 question?

[Martin Sole]

The 75A-4 modification detailing a change of both mixers to 
double-triode 6DJ8 tubes can be found on pages 42-44 of Ham Radio 
Magazine for April 1970. Article was written by Ray Rinaudo W6ZO.

Martin, HS0ZED



On 24/09/2022 01:59, John Gedde wrote:
> Hi folks,
>
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> Long time no post.  I hope I'm not crossing a line asking a R388 question, but if anyone knows the answer, it'd be this group!
>
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> I just acquired a Collins R388.  V102 has been changed from a 6BE6 to a 6DJ8.  It was a not a trivial change since the 6BE6 is a 7-pin tube and the 6DJ8 is 9-pins!!  Looking underneath, you can't tell it wasn't done by the factory (it wasn't.)  The workmanship of whomever made this mod is superb!
>
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> I have only found one reference alluding to this mod in a forum post from 1997.  The poster said he had documentation of the change so this mod must be a 'thing.'
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> Any ideas!
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> 73
>
> John AD2DK
>
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