[AMPS] more...Tube identification

[Skip S Isaham]

Never Assume..

:After multiple layers of BS the bottom line is that it is most likely a
:standard production tube .

This much is prob true...

:Look at it ...if it looks like a 5894, 4CX250 series, etc  it probably
is. The real question :is the filament voltage but that is simple to
confirm.

For a lot of the tubes, yes. But not all. In the later "tube PA years" of
Motorola production, I saw some pretty wild stuff come out. They went
crazy with conduction cooled PA's using two or three different types of
tubes. 

The 450MHz Paging PA's came out with 4CX250's, then retro'd to 350's.
Special versions would come in that had the 26.5 volt heaters on on
board.

There were at least two 5894 "type" tubes I saw in service. 

The 800MHz Repeater PA (which work wells, mod'd to 910MHz) have two
different tubes based on power output. One was an Eimac, the other a
different brand (you explain it to me?).

Somewhere in my storage, I've got an HF Kilowatt Embassy Base Station
from Motorhead using big glass tube(s) like a 4-1000 and one using
3-500z's.

If the someone really needs the help, you can describe the equipment (you
think) the tube was used in. I go to the very large pile of Motorhead
Service Manuals I've stored and look up that tube to confirm the part
number for that amp. Then I check it against my list of known crosses.

:Motorola tried their best to hide info so their customers could get the
:maximum screw job. 

Your right about that one. It was very common to see the same part under
three or four part numbers which varied by the device where the part was
used.  As an example, It got to be a real pain when you'd see a simple
quad op-amp with a Motorhead part number ship in with the replacement
LM-324 part number still attached for $11 each.
The real pain was that it took a week unless you ordered it special
express.

I got to where I kept a list of part numbers and the known cross.

your results may vary

cheers
skipp   wv6f

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