drew.spriggs
Well-known member
Well non-update - had the radio back which took up the little spare time I had.
New choke had increased the output on one of the lower power bands from about 15 to 50w and there was no longer any obvious sparking, but plate voltage was still only getting to about 1200v.
A radio "expert" took a look at it and said it was definitely a power supply issue, so decided to replace all that side of things.Caps have definitely come a long way because the replacements (100uf/500v) are about 1/2 the size of the originals! Also replaced all the 2x6 10D10 diodes (which had parallel 470k resistors) with 1N5407s with no resistors so it should waste a little less power.
Got maybe an extra 5-10w out of it, so did a quick tube swap with some spares the owner had and bingo - right back to 2400v and got 400w out of it
Still a scary thing to work on, but glad I got it working!
I've almost finalised selling my business off and getting ready to set up the new workshop, but also bought the power supplies I needed for the submini amp so should get some progress on it soon
New choke had increased the output on one of the lower power bands from about 15 to 50w and there was no longer any obvious sparking, but plate voltage was still only getting to about 1200v.
A radio "expert" took a look at it and said it was definitely a power supply issue, so decided to replace all that side of things.Caps have definitely come a long way because the replacements (100uf/500v) are about 1/2 the size of the originals! Also replaced all the 2x6 10D10 diodes (which had parallel 470k resistors) with 1N5407s with no resistors so it should waste a little less power.
Got maybe an extra 5-10w out of it, so did a quick tube swap with some spares the owner had and bingo - right back to 2400v and got 400w out of it
Still a scary thing to work on, but glad I got it working!
I've almost finalised selling my business off and getting ready to set up the new workshop, but also bought the power supplies I needed for the submini amp so should get some progress on it soon