You can use microphones for MaxTracs in your GM300 radios. I'm pretty sure they
will also work in the DeskTrac. EBay always has dozens for sale. It's just a
matter of whether you want new or used.
Some MaxTracs do drift. I've actually seen them go as much as 300 Hz off
frequency while transmitting, and it's not as if something heats up. The
microprocessor in the radio TELLS it to change frequency. Most annoying.
GM300s suffer from dirty contacts between the logic and RF boards. MaxTracs
could suffer from the same thing, but for some reason seem to be less prone to
it. The only fix is to remove both boards, clean the pins on the connector, and
reinstall everything. Not difficult, but you have to take just about the entire
radio apart. This might fix the 1 kHz error but the 300-500 Hz error is well
within the spec of the radio so there's not much you can do about it. Shouldn't
hurt anything on a 5 kHz channel.
Bob M.
======
--- On Sat, 9/20/08, Charles Scott <[EMAIL PROTECTED]> wrote:
> From: Charles Scott <[EMAIL PROTECTED]>
> Subject: [Repeater-Builder] Microphones for GM300s and a Desktrac Question
> To: Repeater-Builder@yahoogroups.com
> Date: Saturday, September 20, 2008, 2:52 PM
> All:
>
> Kind of off topic, but thought I'd ask. We have 3
> GM300's we got for
> our emergency communications trailer but we didn't get
> microphones. I
> have two desk mics that came with a couple repeaters we got
> a bit ago
> but we'd really like Hand mics for this application.
> I'd trade the
> desk mics (real clean) for hand mics (real clean) if anyone
> is
> interested. We are also a 501(c)(3), so donations welcome.
>
> Regarding the repeaters... We found two Desktrac repeaters
> that we're
> going to use at a museum ship here. They're all setup
> and ready to go.
> The one thing about them is that the TX frequency is all
> over the
> place for both of them. While warming up they can be more
> than 1 KHz
> off. They do drift in to about the correct frequency after
> warm-up,
> but still drift back and forth quite a bit (300-500 Hz). Is
> that
> normal for these things? (These have MaxTrac radios in
> them.)
>
> Chuck - N8DNX
