1971 Chrysler Radio audio transistors ?

[Sparkey]

Hey;

I just got this original 1971 Chrysler radio but it has distorted audio.
( Chrysler 3501013 Mark 07902)
Turns out that one of the 2 output transistors is shorted.

Both transistors have the Motorola icon and have the numbers 7239 and it looks like 7252 respectively.

I've been trying to identify them (here's a pic)
http://i582.photobucket.com/albums/ss262/UCN_photo/MVC-205F.jpg

I wonder if anyone is old enough or experienced with these to help.
Thanks in advance.

Spark

 

[Allodoxaphobia]

I just got this original 1971 Chrysler radio but it has distorted audio.
( Chrysler 3501013 Mark 07902)
Turns out that one of the 2 output transistors is shorted.

Both transistors have the Motorola icon and have the numbers 7239 and
it looks like 7252 respectively.

I'd have to believe those are date codes, Spark.

Jonesy

 

[N_Cook]

Hey;

I just got this original 1971 Chrysler radio but it has distorted audio.
( Chrysler 3501013 Mark 07902)
Turns out that one of the 2 output transistors is shorted.

Both transistors have the Motorola icon and have the numbers 7239 and it looks like 7252 respectively.

I've been trying to identify them (here's a pic)
http://i582.photobucket.com/albums/ss262/UCN_photo/MVC-205F.jpg

I wonder if anyone is old enough or experienced with these to help.
Thanks in advance.

Spark

I would find a complementary (on the assumption 2 different datecodes) pair
of TO126, 3 or 4A, 50 V or so transistors and jury-rig, in the first
instance.
1972 datecodes probably

 

[spamtrap1888]

Hey;

  I just got this original 1971 Chrysler radio but it has distorted audio.
(  Chrysler 3501013  Mark 07902)
Turns out that one of the 2 output transistors is shorted.

Both transistors have the Motorola icon and have the numbers 7239 and it looks like 7252 respectively.

I've been trying to identify them (here's a pic)http://i582.photobucket.com/albums/ss262/UCN_photo/MVC-205F.jpg

This is the craziest photo I've ever seen, if you want people to ID
the transistor. Can you take a pic that's closer to 90 degrees than to
150? I would like to see what the three digit numbers are in the
corner.

 

[whit3rd]

I just got this original 1971 Chrysler radio but it has distorted audio.

Turns out that one of the 2 output transistors is shorted.

If the (working) one is not a Darlington, it's probably a complementary
pair (one NPN, one PNP); modern equivalent-or-better would be MJE243 and MJE253;
replace both and you can be assured the pair is truly complementary.

It's unlikely the 1971 transistor was of any type currently produced.

 

[spamtrap1888]

   Sam's list six 3501013 versions:
                                Volume  Date    On hand
3501013 (1BBC)                   89     1971    Y
3501013 (GG01303)               104     1971    Y
3501013 (PG 73)                 122     1972    Y
3501013 (1PD1209, 2DP1209)      128     1972    Y
3501013 (2PD1308)               157     1973    Y
3501013                         179     1974    Y



Date codes: 39th & 52 week of 1972

Guess he's wrong about it being a 1971 radio then. If anything the
date codes would be 1970, not 1972.

But why would they put the date code next to the logo?

   I get: "Status 503 Service Unavailable"

Mee too, the first few times.

   I would think it would be in one of the last two manuals listed, but
I'd like to see some photos beore I dig out the books.

If you want a good picture of leads on a power tab package you're in
luck.

 

[[email protected]]

Go to Digikey, they have a selector, get something with gain like 100-300, Vcex about 25, 5 amps and 50 watts Pd and you'll ne fine.

The only thing is this is going to be a low feedback design so if the originals were germanium you need to give it more bias. In fact I am almost suretht one is shorted B-E from your symptom. Look at that driver circuit, ot might need something, likely a small resistor.

There just ain't that much power there.

T

 

[tm]

Motorola never made Germanium power transistors in a flat epoxy
package.

I don't think anyone did.

BTW, you would be surprised at how much it cost to make that radio. Less
than $5 back then.

tm

 

[Sparkey]

Thanks for all the input.

I apologize for the pic, I know that photobucket was acting squirrely even when I was uploading this.

I will check on those NTE 196 and 197.
The resistors that you mention appear to be good. So far, it's only that one transistor that went out.

Yeah, this radio came out of a "1971 Chrysler". Not surprised it good have been replaced or swapped with a newer one somewhere along the way.

Spark...