Audio chip for a connex 3300HP ?

[newoldguy]

Not yet, 202. Still waiting on the voltage measurements from each pin on that audio chip.

Ok here is what i got starting at the back of the radio with the front facing me -
1. 10.8
2. 6.68
3and 4 are tied together 0 volts
5. 1.1
6. 1.1
7. 0
8. 0
9. 6.3
10. 13.7

 

[Unit 75]

OK. Those readings look ok to me. Now to start working back from the antenna .Did you check TR17, is it ok?

 

[nomadradio]

1. 10.8
2. 6.68
3and 4 are tied together 0 volts
5. 1.1
6. 1.1
7. 0
8. 0
9. 6.3
10. 13.7

Pin one is at the front of the radio. You have pin 10 at the wrong end in your list above. Pin four is the fourth one from the front.

73

 

[newoldguy]

OK. Those readings look ok to me. Now to start working back from the antenna .Did you check TR17, is it ok?

Im going to check it it once the radio room gets warmed up

 

[Unit 75]

I feel for ya brother. I live in the south below the Mason-Dixon line and it's been cold here So I can imagine how cold it is up North where y'all are. hehehehe

 

[Unit 75]

Pin one is at the front of the radio. You have pin 10 at the wrong end in your list above. Pin four is the fourth one from the front.

Your correct, Chris. I was able to flip his measurements around lol (orientation wise) knowing pins 7 and 8 are ground. Pin 10 being at 10v and not 13v was the only anomaly I noticed but All the other pin voltages looked good supporting that the audio IC shouldn't be the issue here. I am more interested in the receive strip from the TR17 amp and back. I'm thinking that is where we will hopefully locate the fault.

 

[newoldguy]

ok tr17 checked out good i even replaced it with an nte 107 still nothing

 

[newoldguy]

I feel for ya brother. I live in the south below the Mason-Dixon line and it's been cold here So I can imagine how cold it is up North where y'all are. hehehehe

windy and cold we get all the weird weather here in ohio it can be 60 one day the 20 the next

 

[Unit 75]

Ok. Tr17 should have B=2.20v C=8.0v E=1.50v Is that what you measured?
Next is the 1st RF mixer. That is Tr18. This is a FET.
You should have 1.90v on the source 8.36v on the drain and 0.0v on the gate.

 

[newoldguy]

Ok. Tr17 should have B=2.20v C=8.0v E=1.50v Is that what you measured?
Next is the 1st RF mixer. That is Tr18. This is a FET.
You should have 1.90v on the source 8.36v on the drain and 0.0v on the gate.

tr 17 checked out with the voltages you posted tr 18 is a little higher 2.8 source 8.8 drain and 0 on the gate.

 

[newoldguy]

after looking more IC 9 has my attention i know sometimes manufacturers will cover the part numbers, I am curious if this might have gotten too hot or just a cover up ?

 

[newoldguy]

scratch that ic9 is tx mixer

 

[Unit 75]

Check out Tr36
make sure you have 8 to 8.5v on the collector.

 

[newoldguy]

Check out Tr36
make sure you have 8 to 8.5v on the collector.

TR36 i have 8.3 9.0 and 9.0 and definately not in an easy spot to get at

 

[newoldguy]

i moved on to TR 37 and 38
TR37 0.1 5.5 and .6
TR38 8.5 0 and 8.5