Home  Resources  References  Tubes  Forums  Links  Support  Sale  Search 

   < Previous Message Index Next Message >   

Antique Radio Technical Forum
Delco DS-501 Transistor Convector: Fabricate my own? (pictures)

Posted by mike banner on 07/16/2011 18:21

:::I will add that Delco was notorious for using inefficient single-ended "class-A" output circuits. Being a stereo- those are likely two single-ended outputs rather than a push-pull. And they draw about an amp a piece idle current(!) and probably put out no more than 3-4 watts per channel. A terribly inefficient design by today's standards.
::::Anybody heard of Delco DS-501 transistor or know if there is an 'equivalent' available? (cheap?)
::::I have an old early 1970s (72-76) GM Delco AM/FM car radio/stereo that requires an external 'convector' (called that by Delco radio repair book). I do NOT have this convector for the radio. See pictures: It's a large external alum heatsink w/ two(2) large DS-501 transistors on it along w/ a pair of caps.
::::I wonder if I can fabricate an equivalent unit out of modern transistors? A heat sink and the caps shouldn't be a problem. I'm guessing all I need is a pair of large Delco DS-501 transistors or modern equiv mounted heatsink and 6 wires (3 for each transistor) going to the radio unit. The problem is that DS-501s are not growing on trees AFAIK. That's why I'm wondering if a modern pair of transistors could be substituted?
::::If it helps... it's obviously a 12V radio and requires 10 ohm speakers (8 ohm will do).
::::I have access to one such 'convector' I can inspect. I've cleaned the radio up and it works great w/ the 'borrowed' convector.
::::Here are some pix...
:the speaker should be 3.2 ohms...because of limited voltage out, this load is critical to get full output. A similar transistor in the TO-3 case is the DS-503. Both are germanium aloy, 90 watt colector, and have been used in the same delco circuit design.
ds501 crosses to NTE105, ds503 crosses to nte121...

Delco DS-501 Transistor Convector: Fabricate my own? (pictures) 
pgtr 11/15/2004 11:09 
Rich, W3HWJ 11/15/2004 11:59 
Rich, W3HWJ 11/15/2004 12:02 
 11/15/2004 13:42 
pgtr 11/15/2004 13:50 
Nat 11/15/2004 12:56 
pgtr 11/15/2004 13:48 
Nat 11/15/2004 14:11 
 11/15/2004 16:20 
pgtr 11/15/2004 21:01 
Nat 11/15/2004 21:27 
Nat 11/15/2004 13:10 
Edd 11/15/2004 23:06 
pgtr 11/15/2004 23:57 
radiodoc 11/19/2004 17:03 
Radio Joe 12/12/2004 01:32 
scott romano 04/29/2009 16:59 
mike banner 07/16/2011 17:33 
mike banner 07/16/2011 18:18 
mike banner 07/16/2011 18:21 
mike banner 07/16/2011 18:33 
Cayce 09/06/2013 02:55 
Nick 12/13/2004 21:41 
Nick 12/13/2004 22:12 
Lou 04/29/2009 17:10 
Marv Nuce 04/29/2009 21:11 

   < Previous Message Index Next Message >   

© 1996-2004 Nostalgia Air