>
>Hej!
>
>Your diode in the + 110 volts relay supply is probably shorted. Do not
>forget to
>replace the electrolytic condenser in that supply if so. Is it not strange
>that those SB 220s still run years after years usually without problems.
>Surprising, because that receiving type switch in the output pi filter is
>really weak
The bandswitch used in my SB-220 has a measured breakdown potential of
>1200v more than the actual piv when the amplifier is in operation. In order
to deal with the roughly 10A of RF circulating current, Heath used double
contacts plus forced air cooling on the switch.
> and I did not expect my 1969 (or was it 1970? ) built still
>running well after 30 years. The first in Sweden - had graphite anodes .
I use Amperex graphite-anode tubes in my SB-220. One of them was
manufactured in 1967.
cheers, Prosit
- Rich..., 805.386.3734, www.vcnet.com/measures.
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