[Amps] AL-1500 power relays - update

[Dave Hachadorian]

Thanks for the replies on my original message below.  I checked 
out the AL-1500 today, and it is wired according to the 
schematic, so that was not the problem.  I found the contacts of 
the single pole relay welded shut, but by the time I got the 
relay removed, it had unstuck itself.  I hit the contacts with 
Deoxit and burnished them with a burnishing tool.  I also did the 
DPDT power relay (which had also unstuck itself), and even the 
antenna relay while I had everything open.  All of these parts 
are remarkably easy to service.

I ordered an Omron solid state delay relay from EBay for $5, and 
plan to drive the existing single pole relay from that (~0.5 sec 
delay), as a long term solution.  For now, it's back together, 
ready to go for next weekend's Sprint contest.

Dave Hachadorian, K6LL
Yuma, AZ


-----Original Message----- 
From: Dave Hachadorian
Sent: Sunday, February 1, 2015 4:16 PM
To: amps at contesting.com
Subject: AL-1500 power relays

I used my AL-1500 in the Sprint Contest on Saturday night, and
everything worked fine.

This morning, I was puttering around the shack, and heard a
humming noise.  Come to find out, the AL-1500 was sitting there,
with the power switch off, and all the lamps dark, but full DC HV
was showing on the meter.  I haven't pulled it apart yet, but my
guess is that the surge limiter relay contact has welded shut,
causing the main power relay contacts to weld shut.  I never did
like that idea of using an AC relay as a surge limiter.  Just a
little chatter on the contact as the voltage ramps up and  it
gets stuck.  Then the main power relay takes the full surge next
time it starts, welding it shut.

Anybody have a better way to handle the surge limiting, rather
than the old series resistor / AC relay trick?

Thanks.

Dave Hachadorian, K6LL
Yuma, AZ




.