The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Success. I tested the finals and the driver, and they were ok. Adjusted bias on the driver and finals to spec. I now have transmit. It looks like TR51 was the trouble all along. I want to thank you Rick, without your help this was on it's way to the shop and a big repair bill. This experience wants ...

Back again Rick. I replaced TR51 and TR 50 with higher wattage tr's and the voltages are now correct at those 2. VR13 will now adjust correctly. TR52 still shows 13.82 at C and TR54 shows 0 at C(FM). The charts say 5.6 at those locations. These tests were made with jumper out.
Your serve

Rick, it looks like TR51 is bad. I unsolder it to test it. Will have to order a replacement. Will get back with you when it is installed
Thanks for your help. I didn't think you would hang in this long with a rookie.

Rick, should I take the voltage readings with jumper out? On TR52 I have C=13.82 in AM and SSB. At TR54 C=0 in AM and FM. The Galaxy 88 chart shows 5.6 at both. Is the Galaxy Saturn the same board? It shows 0 volts at C on TR54.

Still have problems. At TR51C, voltage stays at 5.94 in AM and SSB. VR13 only turns down to 5.94. Jumper is out.

Yes, voltages adjust at TR50. Lowest at C is 5.92

Ok, replaced R238, but VR13 will only turn down to 5.94. R237 reads 8.52-8.70.

If I am at the right location, below VR13, someone has changed that resistor to 2 100k resistors solder together. The schematic I am looking at shows a 5.6k at R238. Anyway the voltage is 6.21 one one side and .11 on the other.
Looks like TR51 has been changed before.

Rick, VR13 will not make any changes to the voltage. The pot does show changes in resistance when I checked with the radio unplugged.

Correction on TR52=E 7.26 C 13.72 B 7.82

TR49=E 6.79 C 13.79 B 6.42
TR50=B 13.79 C 6.81 E 13.81
TR52=E 7.22 C 13.72 B 7.22

With jumper out: TR51 B=13.81 C=6.82 E=13.81

With jumper in and TX on AM and USB: B=13.80 C=0 E=13.81

TP9=USB 6.8v
AM 6.8v
Measurements with jumper removed and TX
Next

Rick, I am waiting on the new finals, but have noticed TR51 measures 6.8v. Is this because of the bad finals?

Hi Rick, the voltage is 6.85

Hello, I have a 2980(EPT360014B) that received a lightning shot. The radio receives fine, but has no TX. The red light does turn on at TX. This same thing happened a few years back and a local shop replaced the finals to repair it. I can hear a slight carrier on a nearby radio when I push the mike b...