General Lee Radio Problems No Modulation On Low Power & Other Problems

[blake25537]

Hi, First off I hope I'm posting this question in the right area. OK I traded for a General Lee radio. when I got it, it wasn't working. I replaced the driver the one all the way to the right with the solder side of the board up. Well I know there was a diode placed inline. I still have the diode but forgot where it goes and what direction it goes in, Help Please?

I also replaced TR51 with a 2SB754. I got the radio working again but it's not right. It has good receive and good wattage, but has no modulation at all on low power but it peaks around 20 watts on the hi power setting. Can some help me with this please?

I have looked it over like 100 times looking for something burnt or not connected but everything looks good.

Thanks for any help...

 

[Low_Boy]

Almost every general lee I have ever touched seemed to have a bed variable resistor on the low modulation side. Try replacing that one with one of the same value and I bet you will get your low power modulation back. Also if that 2sb 754 is bad you will get high dead key but no modulation.

 

[blake25537]

Thanks that repaired the modulation parts, I replaced the variable resistor on the low modulation side and it's back. But still not sure where the diode goes. I also found another problem I put a new 2SB754 in but if the radio is keyed up for like a min or longer the side of the radio where the 2SB754 gets real hot. I tested the voltage coming from the front to the back, here is what it's showing
Pin 1 Unkeyed=14.30 volts, Keyed=13.15 volts
Pin 2 Unkeyed=4.97 volts, Keyed=4.70 volts
Pin 3 Unkeyed=13.90 volts, keyed=12.45 volts
Is this normal voltage if not where should I look.

Thanks again for any help.

 

[Crossbow]

Thanks that repaired the modulation parts, I replaced the variable resistor on the low modulation side and it's back. But still not sure where the diode goes. I also found another problem I put a new 2SB754 in but if the radio is keyed up for like a min or longer the side of the radio where the 2SB754 gets real hot. I tested the voltage coming from the front to the back, here is what it's showing
Pin 1 Unkeyed=14.30 volts, Keyed=13.15 volts
Pin 2 Unkeyed=4.97 volts, Keyed=4.70 volts
Pin 3 Unkeyed=13.90 volts, keyed=12.45 volts
Is this normal voltage if not where should I look.

Thanks again for any help.

What power supply are you using? 14.3 volts is pretty high. Yes the side will get hot when you are TXing. That is normal.

Here is a picture of where that Diode goes:

 

[blake25537]

What power supply are you using? 14.3 volts is pretty high. Yes the side will get hot when you are TXing. That is normal.

Here is a picture of where that Diode goes:
View attachment 42066

Thanks for the pic what is that for by the way? They get that hot after only like a min? I'm using a small 10 Amp power supply. I kinda thought it was high voltage also but wasn't sure.

 

[Low_Boy]

Check the voltage coming out of your power supply. Should only be about 13.8 volts I don't see how you could get that high of voltage unless the power supply was putting out too much. They will get hot. I have said ouch more than once when I set my arm on that edge of the radio when covers were off. lol

 

[Low_Boy]

If there is a diode on that 754 get rid of it. It is a swing mod.