UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Hallicrafters SX-43 FM drift.

falcon123 · 30th Oct 2020, 7:32 am

i really dont know what to say about this,perhaps my query was premature. ive been waiting for a dial string and repalacement dial to arrive. as the c41 is buried behind all that and ive nothing to replace c41 with anyway i didnt want to take this apart. but i HAVE been playing it every day on its side and out of the case and have discovered that the drift seems to vary a bit some days. yesterday and today it was only 800@kc instead of +2 mc.. i can only guess as to why. humidity,temperature variation or just something inconsistent with c41 or SOMETHING ELSE.whatever it is i haven't been able to detect it heating various parts of the set when cold with a hair dryer. temp compensated ceramics are not made any more but i did manage to find a limited selection. its impossible to look for something to replace the original part as the while the value of c41 is known.3pf,i was not able to discover its % of compensation. the only thing i can do i guess is try a npo 500v 3pf and see what happens.i suppose the worst outcome is that it remains as it is. it indeed be NICE to know how the set was performing as new in 1949!!

30th Oct 2020, 7:32 am	#19
falcon123 Triode Join Date: Jul 2020 Location: Angeles City, Philippines. Posts: 27	Re: Hallicrafters SX-43 FM drift. i really dont know what to say about this,perhaps my query was premature. ive been waiting for a dial string and repalacement dial to arrive. as the c41 is buried behind all that and ive nothing to replace c41 with anyway i didnt want to take this apart. but i HAVE been playing it every day on its side and out of the case and have discovered that the drift seems to vary a bit some days. yesterday and today it was only 800@kc instead of +2 mc.. i can only guess as to why. humidity,temperature variation or just something inconsistent with c41 or SOMETHING ELSE.whatever it is i haven't been able to detect it heating various parts of the set when cold with a hair dryer. temp compensated ceramics are not made any more but i did manage to find a limited selection. its impossible to look for something to replace the original part as the while the value of c41 is known.3pf,i was not able to discover its % of compensation. the only thing i can do i guess is try a npo 500v 3pf and see what happens.i suppose the worst outcome is that it remains as it is. it indeed be NICE to know how the set was performing as new in 1949!!