[TheList] T500 TX issue

Sun Mar 21 06:12:26 AEDT 2010

Oops...dam screwed up there...and I was thinking I was doing so well with my
answer...

-----Original Message-----
From: thelist-bounces at radiowiki.org.nz
[mailto:thelist-bounces at radiowiki.org.nz] On Behalf Of Neill Ellis
Sent: Saturday, 20 March 2010 5:00 p.m.
To: thelist at radiowiki.org.nz
Subject: Re: [TheList] T500 TX issue

LOL, Vote or scan mode in a T500 :o)

A brand new T500? That's sad, that unit is 20+ year old technology now 
and the stopped production well over 10 years ago.

the T550 or T555 UHF versions can only do 12.5 kHz steps, so they can't 
receive new narrow simplex channels and can't transmit on new narrow 
repeater input frequencies.

You not only need to clip the diodes, it will also need alignment. There 
are three vertical pins between the die cast VCO can on the PCB and the 
diode matrix PCB. Measure the voltage on the center pin relative to 
ground. You need to adjust the VCO for 4 volts on a single channel. On 
Multi channels try to keep the voltage close to 4 volts but not outside 
the 1 and 7.5V range if it varies a lot. Of course you'll then need to 
peak the receiver too.

Regards,

Neill.

Shane V wrote:
> You may be seeing one of the LO's ramping if the unit is in vote or scan
> mode...