Galaxy DX88HL missing ch and low power.

[Novo1]

Galaxy DX88HL, PCB #EPT390014C, PLL #MC145106 the radio has a frequency coverage from 25.165 to 28.755 and has been work fine for the past 2 years but have now lost the bottom 10 ch on band A and 21 to 31 on band D and the output power has gone down to 5 watts on am and fm ssb is about 8 watts was told on a forum to change the reg transistor tr51 this did not help with my low power the output of tr51 is 8.8vdc in am and fm and 12.9vdc in ssb I have removed the driver and finals and tried them in my old galaxy DX11 home base and are good with 10 watts am and fm and about 22 watts on ssb. So can any one help.

Francisco aka Novo1

[Rick]

As for channel problems check the binary adders IC1 and IC2, the N-codes go from 91 to 135 for band A and band D from 226 to 270. Hope this helps, lets us know how you get on.

Rick.

[Novo1]

Rick check codes at pll with vom and are ok and all channels working but when the vom probe is taken of pll it go back to how it was. Tried re-soldering all the parts on the adders board and pll but still the same.

Francisco aka Novo1

[kc8mob]

Ground problem in relation to channels.

For the power output. It could be allot fo things.

[Rick]

If you binary adder board is EPT004410Z, check resistor pack or network RA1 which has 8 pins 1 common pin and 7 resistors pins all the resistors are 47K, you will probably find that the common pin is open circuit, this is not a common problem but I have come across it a few time in the past. You can replace the resistor pack with 47K 1/8 watt resistors. Has for the low power question can you set the bias on the finals. It should be 50ma per final. Hope this helps. Let us know how you get on.

Rick.

[Novo1]

Rick you was bang on the money pin 3 and 4 and 8 open circuit. Check the bias but it will not setup so what next.

Thanks Francisco.

[Rick]

Try replacing resistors R161, 271 both are 1ohm and reset the bias for 50ma per final, you will probably find them to be open circuit. Hope this helps, let us know how you get on.

Rick.

[Novo1]

Rick bang on the money again r161 and r271 gone south put 2ohm will get the right ones. You madeit so easy for me to fix it.

Thanks again Francisco aka Novo1