"who controls the past controls the future,who controls the present controls the past"
di IV3GFN - Giuseppe (Pino) Steffè
One day, a friend of mine brought me his power amplifier, an Heathkit sb-220 for a check.
Due to the fact that the preceding owner was an inveterate smoker, the interior were covered by a tarry patina and so the other components.
When I turned it on a smell of bad tobacco invaded the shack.
This way we decided to effect a deep revision and to clean carefully everything.
Someone modified the radio in wrong way for the 160m. The original parts as the plate choke had been lost so I rewound another one like the original value of 50 uH. Adding another choke of 60uH, it will be ready for a future updating for the 160m coverage as suggested by Rich, AG6K. I followed his instructions to make important improvements that you partly can see below.
Download SB220 manual - (PDF 15.0 MB)