03-03-2016, 10:04 PM
(03-03-2016, 04:28 AM)Arran Wrote: <snip> they do not have to be mica at 455 KC precision ceramic will work fine. </snip>
Arran - just to clarify (for my own knowledge), when you say precision ceramic I assume you mean NP0 or some other tight temperature spec ceramic? Tube radios get warm... and 'warm' changes the capacitance, albeit to a different degree with different cap types... which is one of the reasons I believe silver mica's are used - because they don't drift much with temperature change...
I'm inclined to replace silver mica with silver mica, but NP0 ceramics (or equivalent) I believe are ok? Or the old tubular ceramics? I did try to find some NP0 caps down here in Hobbit land but they were 500 minimum order quantity... which was about 498 more than I needed.
Stunning radio by the way - we (to the best of my knowledge) never got those down here in NZ... might be something to import one day.
Cheers
Steve
There are no personal problems that can't be overcome with the liberal application of high explosives
