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

I have a galaxy dx 88hl board #360014b that will not key up tried different mic still wont key radio powers up and voltages at regulator check good. Also checked wiring on mic plug which checked good also.Thanks in advance for your help.

will it transmit in ssb.or does not tx at all am or ssb...............ramblingman

The radio will not transmit on am or ssb radio will not key up at all in am could ic4 be the problem . thanks for your help ramblingman.

Check Pin 7 of IC4 in RX and TX also check transistor TR38 in TX, let us know the voltages.

Thanks for your help Rick i can only give you the voltage readings in rx because the radio will not hold a carrier or key up at all. Volts on tr.38 are b.7.84 c.0 e.8.38 and ic4 volts are pin 1. 4.31 2. 4.32 3. 4.32 4. 0 5. 4.27 6. 0.99 7. 7.26 8. 7.97 all voltages look good except for pin 6. according to the voltage chart i have. Thanks again for your help.

It sound like a VCO or PLL fault. check the voltage at TP2 on band B and C channel 1 and on channel 40. let us know the voltages.

Checked voltages at tp2 band b channel 1 1.78 40 2.36 band c channel 1 2.37 40 2.99 I don't know if this has anything to do with it or not checked tr 30 and it has no voltage on base collector or emitter. Thanks Rick.

Right then if you have on volts on TR30 that most likely fault. It may be just a cold solder joint around TR30, check to see if you have volts at R153 and R154.

Do not have any voltage r153 or r154. Thanks!

Just let us have the voltages you have, that all you need to do.

There is no voltage on TR30, R153 and R154. Where else should I look? Thanks for you help Again Rick.

You are doing the test in SSB mode yes?

VOltage on TR30 in ssb are good. And I do have voltage on R153 and 154 in ssb. Trying to find out why radio will not key up in AM. Also will not transmit in ssb.

TR30 is only switch on in SSB and TX mode.
Ok then check the pins 1 to 9 on the PLL (IC5).
Do you have a frequency counter?
You will get the radio working again if you can answer my questions.

No i don't have a frequency counter at this time i loaned it to my brother. Voltages on ic5 pins are 1-7.90 2-3.72 3-4.03 4-4.05 5-3.80 6-7.80 7-1.51 in low band 4.40 in high band 8-7.86 9-0.11 in a band 6.21 in h band. I appreciate your help Rick.

Lets just try this unsolder one side of D66 near IC4 and see if you get TX?
check the voltage on pin 6 and 7 also each side of D66 in TX.

Ok after unsoldering d66 radio will key up voltages on ic4 pin 6-3.18 7-7.28 volts on diode are 7.83 cathode side 3.18 on the other i noticed voltage on pin 6 checked good after unsoldering d66.

What is the radios frequency showing on band E channel 19 when you go in to TX?

You real need a standalone frequency counter to what the freq is at TP3.

It look like you have a fault with VCO or loop osc.

I will have to get my frequency counter back to check tp3 the radio is showing 27.635 on 19 band e Thanks for your help Rick i will have to work on it tomorrow i have to go to work now isnt second shift great. Thanks again.

Rick thanks for all the help on this radio i still dont have my frequency counter yet thought i would update you on the progress i have made on it. I resoldered d66 and the radio is keying up just fine now recieve is good but every time i key the mic up all the radio wants to do is squeal even on ssb any sugestions on what may cause this. Thanks again.

Try unsoldering d66 and to see if it still squeal?
Try turn the mic gain right down and see if it still squeal?

Rick i unsoldered d66 again and it is still squealing even with mic gain turned all the way down. Looking at the meter you can tell it is still squealing and you can hear a little feed back through the mic itself. Also i have a frequency counter now if you still need those readings you asked for tp3 channel 19 e band shows 16.940020 thank you for your help.

It sounds like some one has disabled the AMC, check that TR34, R249, D80 and D83 has not been removed?
It maybe a fault on the Echo board but check the above first.

All those are still in place including TR32.

I think it would be best to start a new post, with some think like
Galaxy DX88HL Audio squeals in TX

Can you check to see if you have the same problem it the PA mode, plug an ext speaker in to the PA socket switch to PA. Let us know how you get on.

Can you give me the voltages of IC4 in the TX mode.

Still squeals when ext speaker is in the PA socket.

voltages of IC4 in the TX mode- pin 1 4.35 , 2-4.37, 3- 4.34, 4-0, 5-2.48, 6-3.20, 7-2.38, 8-8.02.

I can start a new thread since the keying problem has been fixed. Thank You for your help.

Rick i would like to thank you again and every one else for the help on this radio finally found the problem it was a burnt choke on the back of the mic socket every thing works fine now. "I also would like to wish you and every one else on this forum a Merry Christmas and hopefully a better new year Thank you all".