Thanks Bob & Greg! As one might imagine,
I really need one more project to do around here ;)
I had looked at the mod Kevin posted, and even
looked for the parts, but none were readily available.
After that, I started giving serious thought to a
wholesale change out to MASTR II radio gear...
I am getting my M2 stuff together, but I'll still
be left with the Hamtronics stuff with the crystals.
Thanks for the tips!
73,
Steve
----- Original Message -----
Sent: Wednesday, April 14, 2004 2:30
PM
Subject: RE: [Repeater-Builder]
Hamtronics exciter
I've done the
FM
PL mods to this type of
transmitter to get direct FM for CTCSS injection. The modulator on that
exciter will not handle CTCSS so the mod is required for a nice clean PL.
It's a rather simple mod with only a few parts and is documented on the
RepeaterBuilder website.
Gregg R. Lengling, W9DHI,
Retired Administrator http://www.milwaukeehdtv.org K2/100
S#3075 KX1 S# 57 Politics is the art of appearing candid and completely
open, while concealing as much as possible. -States: The Bene
Gesserit View
-----Original
Message----- From:
[EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, April 14, 2004 2:05
PM To:
Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder]
Hamtronics exciter
Does anyone think it would be
feasible or practical to modify the TA-51 to implement an LC phase
modulator? Just how easy or how difficult might that
be?
You could use a varicap, a
tunable inductor, and a capacitor to build a circuit that's resonant
at the crystal frequency, and that's fairly easy. But such a circuit also
generates an AM component that must be removed, so another transistor stage
is needed for isolation. That probably means you're up to a little
perf-board ('blob') addition to the exciter.
BTW, we think that the GE PM
exciter suffers from a little of the same insufficient isolation problem,
but that's another rainy-day investigation.
Incidentally, the
RC version of a phase modulator is sometimes
called a reactance modulator, and the LC version is called
a tuned circuit modulator.
Yahoo! Groups Links
|