18-11-2012, 07:48 PM
Hi,
Thanks both for the input. Earlier today, someone on UKVRRR suggested adding the "2SC" to the numbers, and that seems to work: http://www.radiomuseum.org/tubes/tube_2sc185.html
I've seen transistors where the "2S" has been dropped, leaving the A, B, C or D, but this is a new one on me. Especially as the letter is quite significant - my understanding is that A and B were used for PNP transistors, and that C and D were for NPN.
Actually, the Wikipedia article summarises that quite well: http://en.wikipedia.org/wiki/Transistor#Part_numbers
I was surprised to see that the 2SC185 is silicon, given the age of the radio (mid 1960s).
If anyone wants to see this thing, I've put the pictures here: http://www.vintage-radio.net/forum/showpost.php?p=569774&postcount=4
Without a schematic, it's difficult to know what to do. The transistor measures OK at DC (well, with just a DVM at this stage), but it's a lot of hassle to get thing in a state where I can test it. It would be really annoying to replace the transistor (perhaps with a BF184, knowing this ought to work well here), only to find that it's a problem with biasing components. I've tried reverse-engineering the schematic, but it's really tough, as you can see.
Mark
Thanks both for the input. Earlier today, someone on UKVRRR suggested adding the "2SC" to the numbers, and that seems to work: http://www.radiomuseum.org/tubes/tube_2sc185.html
I've seen transistors where the "2S" has been dropped, leaving the A, B, C or D, but this is a new one on me. Especially as the letter is quite significant - my understanding is that A and B were used for PNP transistors, and that C and D were for NPN.
Actually, the Wikipedia article summarises that quite well: http://en.wikipedia.org/wiki/Transistor#Part_numbers
I was surprised to see that the 2SC185 is silicon, given the age of the radio (mid 1960s).
If anyone wants to see this thing, I've put the pictures here: http://www.vintage-radio.net/forum/showpost.php?p=569774&postcount=4
Without a schematic, it's difficult to know what to do. The transistor measures OK at DC (well, with just a DVM at this stage), but it's a lot of hassle to get thing in a state where I can test it. It would be really annoying to replace the transistor (perhaps with a BF184, knowing this ought to work well here), only to find that it's a problem with biasing components. I've tried reverse-engineering the schematic, but it's really tough, as you can see.
Mark
