Short out the contacts with a piece of wire and try it again.
That will tell you if the band switch is bad.
What is the input SWR on the bands that don’t work?
73
Jim W7RY
-----Original Message-----
From: amps@n3kf.org
Sent: Wednesday, October 28, 2015 2:39 PM
To: amps@contesting.com
Subject: Re: [Amps] Heath SB1000 no power out on 10 and 15
So how does one know if the band switch is good or bad for RF? My band
switch obviously had some burning. No contacts are missing. But the switch
plate is definitely etched. I cleaned it with some alcohol, and got lots of
dirt off of it. I have not reassembled yet to see if that changed anything.
The ceramic wafers have no carbon tracking. But like I said the metal plate
definitely looks to be etched. Guess I need to try it after the cleaning. Is
there a decent contact cleaner I can use to really clean the switch up that
is not detrimental to RF?
-- Ken. N3KF
Sent from my Android tablet
-----Original Message-----
From: amps@n3kf.org
To: amps@contesting.com
Sent: Tue, 27 Oct 2015 8:50 AM
Subject: [Amps] Heath SB1000 no power out on 10 and 15
Hope this is not a repeat from me. I have an SB1000 (AL80A clone) I built
back in the 80s. Lots older and with back issues it is hard to get around
and work on now. I have the original and a new tube and the amp acts the
same. On 160 through 20 meters all seems to be OK. However, on 10 and 15
meters there is no output. The oddity is that the meters show plate and grid
current just like normal and the tube heats up. I figured this is an easy
one and I smoked the band switch. Other then some carbon tracking, the
switch looks good. Cleaned it up some, but no change (really did not expect
it since the output does not exists). The PO meter of the amp does not show
any power on any band. Another problem, but I think I have read about this
one. So is the no power out a common problem? If not, I guess I got to dig
into it. When I said I get grid and plate current, that is with low power
since obviously if this is not putting power out, that RF must be
dissipating somewhere! Thanks f
or any thoughts.
-- Ken N3KF
Sent from my Android tablet
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