[R-390] Unfamiliar R-390 variant on ebay overnight

[Bob Young]

Yes, serial number 5, that is strange.

Bob
kb1okl

________________________________
From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on behalf of Jacques Fortin <jacques.f at videotron.ca>
Sent: Saturday, April 25, 2020 11:11 AM
To: R-390 at mailman.qth.net <R-390 at mailman.qth.net>
Subject: Re: [R-390] Unfamiliar R-390 variant on ebay overnight

Hi all,

The new pictures added by the seller raises more questions than they give
answers.
The back panel looks like a homemade job, and not a good one either.
If this set was originally a normal production R-390, why the two connector
blocks had not been kept ?
Why also the signal level meter is on the left side when the related wiring
have to be at the right ??
Looking at the only underside picture provided, the PSU seems to be a
"normal" one, despite that the 26Z5s had been replaced by SS diodes (we can
even see one in the picture, thru the hole left by the tubes sockets
removal).
The filtering cap(s), however, are not the normal production one. Parts
replacement ??? Seems to show 5 - 1000VDC on the one that can be "read".
On the opposite corner, the C103 is an electrolytic, instead of the "normal"
oil-filled 10µF, 300V GE part.
The AF/regulator deck looks like a "normal" one, despite that one tube is
missing in the provided picture (have to be one of the two 5651).
But the three 10K to 600 ohms transformers are there, so what happened to
the LINE Output controls, meter/range switch and connections ???
The most puzzling for the end: despite that the "bottom" picture did not
have a good resolution, the serial number on the 70H-2 PTO can be read.
Are you seeing the same as I do that this number is only a 5 ???
So.... A basement hacking job, or a real pre-production item ?
Whoever will buy this one will have a chance to provide definitive
answers...

73, Jacques, VE2JFE

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