I have repaired exactly the same problem in two VHF
amps,
and in one UHF MSR-2000, the problem is in the
feedtrough
that carries the + side of voltage, seems it gets very hot at
high
power level and melt the solder .....
Juan
----- Mensaje original -----
Enviado: Tuesday, September 07, 2004 7:43
AM
Asunto: RE: [Repeater-Builder] MSR2000 PA
out - again...
Have you done any troubleshooting yourself to find out what is
failing. Did you go thru the troubleshooting routine in the
manual. I've found that MSR amps are very good and only fail very
rarely. I've seen the Choke feeding the power to the mid level amps
have a bad connection...you'll read the voltage on the collectors in idle,
but when you go to TX the voltage will go away. I've seen this on a
number of amps of the 2000 series. I've also seen people repair these
by replacing the transistors in the mid level amp, and of course it works
for a while because they disturbed the choke and got a decent connection
again. But the only real way to repair it is to remove the board and
remove the choke and clean the leads and reinstall it and make sure it is
well soldered.
Gregg R. Lengling, W9DHI, Retired Administrator
http://www.milwaukeehdtv.org K2/100
S#3075 KX1 S# 57 Member: ARRL, RSGB, RCA, WERA and
ORC
-----Original Message----- From: N9WYS
[mailto:[EMAIL PROTECTED] Sent: Tuesday, September 07, 2004 9:01
AM To: Repeater-Builder@yahoogroups.com;
[EMAIL PROTECTED] Subject:
[Repeater-Builder] MSR2000 PA out - again...
I have an MSR2000 on
444.550 for the local ham club / county EMA. The PA (a 110W model) is
out again. We just had this repaired by the local Motorola shop, with
whom we've had very good results from in the past. We're running the
PA at about 80W, so I'm thinking we didn't "burn it up", but I can't help
but wonder if there is anything inherently wrong with the MSR2000 PA for
UHF. This is the third time the PA has failed in this
particular machine in about a 2-year time frame. (This was a repeater
originally tuned for 460 MHZ, and brought down to the ham band.) This
particular machine has been a pain in the @$% - RX sensitivity isn't what
it should be, PA keeps going out, etc. Seems like we're up at the
site every couple of months do make some sort of repair on it. I'm
wondering if we should just cut our losses and get another machine,
or should I keep plugging away at this repeater? If we do decide to
chuck it, how much can I expect to spend to get a comparable replacement -
we use this machine during severe weather season for forwarding reports to
the NWS, and it's open other times. We want to add remote RX sites
(you've probably seen my inquiries about those in the past) but I don't
want to start adding remote RX sites until I get the main repeater working
reliably. I'm open to suggestions... Thanks, Mark -
N9WYS
Yahoo! Groups
Links
Yahoo!
Groups Links
<*> To visit your group on the web, go
to: http://groups.yahoo.com/group/Repeater-Builder/
<*>
To unsubscribe from this group, send an email to: [EMAIL PROTECTED]
<*>
Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Yahoo! Groups Links
|