Hello - I have had a failure in the Heathkit HL2200 with all the Harbach mods - with at least one release of smoke. I am researching the source of the failure but do have as evidence a burned grid RFC, 1 mh, 4 stacked series coils (I think it is similar to a Hammond Engineering 1534A which is not made anymore. I was not aware how rare these are since all the parts houses I use have this item as obsolete. With the large population of these and similar amplifiers and also burned out RFC's I would think someone has an alternate or has a reliable source. I am monitoring ebay now for such a NOS unit and have the word out to local hams/hamfests.
Thanks for any help in pointing me towards one (or two).
Bob - NS7H
Hi Bob,
The first thing I would do is to get rid of all the Harbach junk, because you don't know if it was installed properly.
Secondly, remove all of the grid components and replace them with 1/4" copper strips directly to the closest ground point.
The third thing to do is to replace ZD1 with a 12V 50W unit, such as the NTE5254A.
Phil - AC0OB