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

Radio Make and Model: Galaxy Dx 55v non mosfet version PCB Number: 360014c PLL Number: Test gear available: volt meter,signal gen.,rf probe,watt meter Symptoms: Radio has no modulation What is working: PA works,receive is good,rf power output is good. What has been tried: Tried different mic,changed...

I have used the mrf497 hope this helps.

Have you tried www.bkmanuals.com ? or www.surplussales.com They have a large selection of service and owners manuals.

Hope this helps http://www.freeinfostuff.com/ Brian's info page.

If the volts are correct at Q124 pre driver with no rf signal i would check volts at Q134 TX amp and for rf signal if volts are correct and still no rf signal i think IC106 is TX mixer i would check volts to see if they are correct and i think you should have a frequency reading at this point to che...

When you say driver and final are OK does this mean the volts are correct on both? Also are the pre driver volts correct?

If this radio has the frequency counter plug in on the back of the radio the two wires go to it and have nothing to do with the power these were installed from factory.

Make sure the coax is hooked up correct if it is then Q1 keying transistor has probably went bad it should be a pn3907a transistor. Hope this helps.

Don't know if this will help or not, but there is a wire wound choke on the mic. socket board that will sometimes burn or become open that will cause a squeal or hum in transmit when mic is keyed even with the mic gain turned down and talk back turned off. hope this helps.

From looking at the pictures someone has done a swing mod. to this radio this is why you have a low carrier. To be able to raise your carrier you have to change the resistor to a higher value that is located on the solder side of the board located were JP6 used to be or you can remove the electrolyt...

Rick i changed final and driver and still have same results i also checked PSU and the voltage is staying steady with no drop in volts. Thank you also unit 67 for your help i think i will take this radio to a tech because i don't care much for working on surface mount radios. Thank you both for your...

I acquired a RCI2995 main board number EPT695012B that only has 1 watt of output power. The person I got the radio from had replaced Q60, Q62, and Q66. Thought the problem was in the linear so I unplugged the coax from the linear board that went to the antenna plug and installed it on the main PC bo...

Thank You to everyone who has helped me. I remounted the transformer properly and now the hum is just very faint with volume turned all the way down. With volume turned up you can't hear the hum in the receive anymore. Thanks again for your help

Not for sure if this is the correct one but hopefully it will help you in locating where your wires would go.

Rick thank you again for your time i will try mounting the transformer different to see if it helps if not then i will try the caps and let you know how things turn out. Thanks

Rick i thank you and ramblingman for your time. The radio has the original main pcb board in it and the only thing that has been changed is the transformer and the power pcb and i found out they came from a 10 amp Pyramid power supply. ramblingman the ground wire is run exactly as you described and ...

Thank you for your help on this ramblingman i have checked the caps and they both check good it has two 4700uf caps on the power supply board and they share the same ground as the main PCB board on the radio. I have also unhooked frequency counter to make sure this wasn't the noise i was hearing but...

Thought i would update every one on this radio i shielded the transformer and still have power supply hum in the receive only. In transmit every body that i have talked to said there was no hum in the transmit. Any ideas as to what i can do to eliminate the hum in the receive? Thanks for your help.

Make sure that the fuses are good on both positive leads going to the radio because if the orange wire is not connected to a constant 12v source every time you turn your radio off or switch to weather bands when you go back to cb or turn the radio back on the radio will go to channel 9. Make sure yo...

Dakota325 i have seen the solder joints on TR41 crack or break from board movement do to loose screws on main board cause this problem. Sometimes it is hard to see without a magnifier glass try pressing on the board in this area to check or touch up solder joints also check for cold solder joints on...

Zodiac still can't find any copper foil or thin sheets of copper in my area would the copper braid from the shield of coax cable work to help eliminate this or do you have any other suggestions on what else would work? Thank you for your help

Zodiac thanks for the information i will get back to you on how things work out having trouble finding copper foil or thin sheets of copper in my area. Thanks

Thanks for the information Frogman296 i have hooked the radio up to a external power supply and the hum was not there. Zodiac thank you also I may have to try what you suggested to see if it works. I was also wonder if installing the power input PCB board on the AC line with the 2 chokes and the 4 c...

I have a Galaxy Saturn main board #360014B that has a power supply hum it looks like someone has removed the original transformer and power supply board and installed the inner parts of a external power supply because the board is different and the transformer is not sealed all volts are correct goi...

Thanks for the information Billy may try this later i have been receiving good reports the way that i have it set up now but if this makes the modulation clearer i may try it also i did not remove any modulation limiters so radio has good clean modulation now. Thanks