[TenTec] Your success with Motorola transistors.

Katz Ajamas ajamas.rn at gmail.com
Fri May 26 13:58:14 EDT 2017


Thanks for posting this. I have a small stach of Motorola VHF transistors
for their mobile radios. I forget the PN at the moment. Wonder if you
reacall the PN of yours or the model Motorola they were removed from.


-Bob ah7i/w4

Message: 8
Date: Fri, 26 May 2017 01:38:19 +0000 (UTC)
From: Curt Benjamin <k8aicurt at yahoo.com>
To: "tentec at contesting.com" <tentec at contesting.com>
Subject: [TenTec] Substitute PA final transistor replacement test
Message-ID: <2093502255.166558.1495762699821 at mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8

I picked up a 546 Omni D, series B at Xenia that the seller said worked but
had a stuck PTO so I figured it might be an easy fix and maybe something I
could sell to a new ham who wants a starter rig for HF. I managed to clean
up the PTO so it's all greased up with Super Lube and working great but I
later found that the finals were bad.

I have been saving a pair of PA finals from a VHF, low band Motorola
Maxtrac for such an occasion to try out. Knowing that xistors that are
designed to operate class C would probably not operate well with bias
applied, I figured I'd try them anyway - heck, I suppose I could keep it a
CW-only rig until I find some suitable xistors.

Well, they are holding the correct bias current and it's transmitting 110W
out, and getting good audio reports on fone. Not too shabby for a set of
free finals salvaged from some old Motorola radios.
I still haven't checked it on a spectrum analyzer but I figure I'll take it
into work soon and check it out when I get a chance. I suppose the IMD
characteristics are inferior to devices that are designed for this
application but if it's reasonably clean and legal, what the heck.

Curt, K8AI

-do not look into LASER with remaining eye!

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