[HATS] Aural transmitter for ATV Repeater

[Mike Dees]

Eric,
I built the aural transmiter (443.750MHz) for the BRATS ATV repeater
(the second oldest ATV repeater in the USA).  I used a 450 MHz
Mitrek radio (30 watts I think), it was a pretty simple mod.  There
is a voltage divider that feeds the modulator in the UHF version of
the Mitrek, as I remember the VHF version does not have this voltage
divider.  I removed the voltage divider so more voltage was feed to
the modulator.  It worked out fairly well, the deviation was
symetrical up to about 21 KHz.  Above that it was just a little
asymetric.  I also bypassed the final amplifier stage in the
transmitter (the output still runs through the harmonic filter); it
produced about 3 watts when set to full power, which is just about
right for a video transmitter putting out 100 watts peak.  The
transmitter can run continuously without a fan.  It has been in the
repeater for years with no failures.  I don't know if a 450 radio
will go to 430MHz.  It would probably be easier to use a 403-420
Mitrek.
73,Mike N3EZD

----- Original Message -----
From: "Eric Kc5Fog" <kc5fog@hotmail.com>
To: <HATS@stevens.com>
Sent: Friday, May 02, 2003 9:43 PM
Subject: [HATS] Aural transmitter for ATV Repeater


I've been working on the Galveston 426.25mhz / 1252mhz ATV repeater for a
while and I've finally got just about everything finished, except for the
audio  on the 426mhz video output. I want to run a aural transmitter on the
430.75mhz. I know hats is using a separate aural transmitter. I believe it
is a modified master II. Can anyone give me any info on any radio in the
freq range that can be modified for 25khz deviation for use as a Aural
sub-carrier transmitter ??

Eric KC5FOG
GCARC