I really dont think the tube could go bad setting in a damp basement.
However pulling the tube out and turning on the b+ is a good way to find
out. My guess is the HV Capacitor is bad or the diodes have blown, maybe
both. It is usually not a transformer in those cases.
Ron W4WA
Rich Saik (by way of Brian K. Short KE7GH ) wrote:
>
>
>
> I came across your web page while searching the net. I wanted to ask
> you a couple of questions about an amplifier I've recently acquired
> from an estate. The amp is a Heath SB-1000, but was kept in a rather
> humid basement for a fair period of time. When I applied power for the
> first time, it immediately popped the fuses. So, I have been
> carefully taking it apart, cleaning it, checking components and their
> general availability.
>
> I have come to understand that the Ameritron AL80A was essentially
> identical to this machine, so I contacted their customer service
> group. I originally suspected a bad transformer, but they pointed
> out that the symtoms I experienced may well be due to a bad tube.
> There was a web page issued on the successor to the AL80A, the AL80B,
> and it did discuss this issue. I was advised to apply power without
> the tube (3-500Z) plugged in and see if it still takes out the fuses.
> I haven't done that yet, but probably will very soon.
>
> I was reading in your web page of the "getter" technique. That
> sounds like a reasonable approach, but I was wondering if you can
> speak for that approach yourself. Also, do you have any idea how
> long one would have to apply filament voltage in order to drive off
> the gassing problem? Are we talking about a matter of minutes or a
> couple of hours, or what?
>
> I did take the time to ohm across the transformer, but I didn't see
> anything earth-shattering (direct shorts, etc.).
> Of course, that does not say what would
> happen at high voltage conditions. I thought about disconnecting the
> transformer outputs, insulating them well and applying power. Then,
> if fuses weren't blown, I could reconnect each output separately and
> then see what happened. That seems to be a compatible approach with
> the one described in the web page.
>
> When I talked with Ameritron, they stated that a new transformer
> could be ordered for about $115 and, a new tube is in the
> neighborhood of $180. However, I'm trying to verify each of the
> components before I dump money into this beast. Any other
> suggestions or ideas?
>
> Thanks, OM.
>
> de WB9UCA.
>
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