Maker Pro
Maker Pro

delco DS 501

crazzyotto

Jul 5, 2011
4
Joined
Jul 5, 2011
Messages
4
hi, i know that the NTE105 is a replacement for the DS501. i have a 1975 am/fm mono radio which only makes sound at a VERRY LOWW volume; so, i suspect the power xistor - a DS501. however, i can not find the value of the resistance from B-E/E-B or B-C/C-B so i can not tell if the unit is dead.
can anyone help w/ this info?
tnx, crazzy
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
Have you measured these resistances (or voltage drops using a diode test function)? Were these in-circuit or out of circuit? What are they? (You won't find "published" values for them) Do you have a circuit diagram?
 

crazzyotto

Jul 5, 2011
4
Joined
Jul 5, 2011
Messages
4
resistances

hi, yes, my VOM shows B-E = 72 ;E-B = 70 ; B-C = 200 ;C-B = 96 ; and C-E = 49 . these are all w/ the collector lifted off the circuit but the wires still in circuit to the B and E.
v drops in the 'diode test' mode: B-C 0.98; C-B 0.04; C-E 0.02; E-C 0.36 .

guess the thing is SHOT!
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
a lot depends on the rest of the circuit. But I agree it does look suspicious. Is there any way you can disconnect another lead (B or E)?
 

crazzyotto

Jul 5, 2011
4
Joined
Jul 5, 2011
Messages
4
well, i guess i can unsolder 1 of them and re-test. ya think there's any chance that it could be OK w/ those results?
 

crazzyotto

Jul 5, 2011
4
Joined
Jul 5, 2011
Messages
4
well, i suppose that i'll hafta unsolder it in any case IF i can locate the alt [NTE105]. so might as well do it now. a local radio shop offered to 'fix' it for $100! i went and bought a cheap stereo w/ tape player for $30 to use. but i'd like to get the orig working to keep the vehicle in 'as delivered' condition. it is a 1975 Cosworth Vega.
 
Top