[Amps] Heath SB1000 no power out on 10 and 15

[amps at n3kf.org]

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

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-----Original Message-----
From: amps at n3kf.org
To: amps at 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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