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smokinjoe

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...

smokinjoe

I have used the mrf497 hope this helps.

smokinjoe

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

smokinjoe

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

smokinjoe

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...

smokinjoe

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

smokinjoe

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.

smokinjoe

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.

smokinjoe

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.

smokinjoe

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...

smokinjoe

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...

smokinjoe

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...

smokinjoe

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

smokinjoe

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

smokinjoe

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

smokinjoe

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 ...

smokinjoe

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...

smokinjoe

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.

smokinjoe

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...

smokinjoe

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...

smokinjoe

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

smokinjoe

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

smokinjoe

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...

smokinjoe

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...

smokinjoe

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

smokinjoe

Thought i would let everyone know that i changed FL3 10M4D crystal filter and have full output on radio in am now which is keying 2 watts and swings to 35 watts with modulation. Thanks

smokinjoe

Thought i would post what i did on this radio for others to try or use for reference. I installed a 1N914 diode from the emitter of TR49 to the collector of TR51 with banded end facing TR51 now with the RF power adjustment turned all the way down i can set carrier with VR13 to 1 to 2 watts and the r...

smokinjoe

Marvin i forgot to mention L503 choke that runs from power plug to the board check to make sure it is not burnt and is making connection to the board hope i am not confusing you. maybe one of the things i mentioned will help fix things let me know if this helps. Thanks

smokinjoe

First thing to check is the fuse which i am sure you already have if the radio keeps blowing fuse check D93 to make sure it is not shorted if this checks OK i would check TR41 this supplies power to the front of the radio the volts should be B.12.4v, C.8.53v, E13.16v hope this helps.

smokinjoe

I have a new Stryker radio that i got a good deal on from a friend that was not satisfied with the output on the radio the main board #9821R20 and has the IRF520 finals. I checked the output on the radio and with the rf power turned all the way down the radio only keys 1/2 watt and swings to about 2...

smokinjoe

Is the fault still there even when the mic is not connected to the radio?

smokinjoe

Try checking TR21 voltage in RX b. 0.24v c. 2.99v e. 0v and in TX mode b. 2.55v c. 1.87v e. 0v. If the volts are ok check TR22 and TR23.

smokinjoe

TR38 is the 2sc2166 driver the keying transistor is located toward the front of the radio hopefully some one will get the number for you if not i will try and look it up for you tonight.

smokinjoe

The radio has low RF power in AM mode only 1/2 watt output VR803 only sets carrier. SSb mode has full output. Thanks

smokinjoe

Check to see that someone has not replaced TR38 and installed it wrong i have seen this happen and cause this problem. If the driver has not been replaced and is installed correctly check the keying transistor it may be shorted not sure what the TR number is right off maybe Rick or someone will chim...

smokinjoe

I have a Galaxy Saturn main board #360012B that has only 1/2 watt am power output. The radio has 30 watts output power in ssb mode. I have checked volts at TR51 and they check good. I can adjust the volts on the collector with the high power adjustment in the radio and with the RF power control. Any...

smokinjoe

There is one other thing i noticed on this radio that i forgot to mention is the driver and final bias will not adjust. Thanks in advance for any information.

smokinjoe

Rick i would like to thank you for your help on this radio because it has a few things wrong with it and i was trying to take care of one problem at a time . I now have rf power radio keys 2 watts and swings to 30 with modulation now i need to find out why i have a high carrier on usb and lsb anyone...

smokinjoe

Rick I forgot to mention that there are 2 places on this board that are marked TR30. I have been checking the one next to X4. The other is towards the rear of the radio, I guess i have been checking the right one?Thanks.

smokinjoe

I have checked for broken traces on the board and have not seen any the only connections on the emitter of tr30 is some caps and a resistor.

smokinjoe

Rick i have checked for cold solder joints around x4 and tr30 on the emitter of tr30 i have .31 with probe connected. The collector has 7.25 volts in tx. Also x4 shows .29 on both sides with probe connected. Thanks

smokinjoe

Rick i am not sure what the input pins on ic9 are but the two pins closest to L44 show .01 on volt meter in tx with rf probe connected. R231 shows .60 in rx and tx and R232 is 0 in tx with probe connected. Forgot to mention that i have already replaced ic9. Thanks

smokinjoe

Rick i have a rf probe now and i have checked the finals the driver and the predriver and there is no rf on any of them were is the best place to start in the rf section and follow signal that goes to predriver? I checked rf probe on good radio and it is working properly. Thanks for your help.

smokinjoe

Rick thought i would let you know that i returned radio back to stock and i still have the same results with no rf power out put i should have rf probe ready in next couple of days. Thanks

smokinjoe

Thanks for your help Rick d16 had gone short replaced it and every thing is working fine. Thanks

smokinjoe

Thanks Rick i will check these and let you know how things come out.

smokinjoe

I have a connex 3300 main board #ept360014b that squeals when i turn the volume up i can turn the rf gain back to get it to stop but this limits the receive range also it is worse on some channels than others also it will stop squealing if i turn the nb/anl on or off. some channels it must be on to ...

smokinjoe

Rick thanks again for your help i don't have the original finals but i may have a new set of 1969 finals and a 2166 driver. Let me get back to you over the weekend i may try and put the radio back to stock and see if the problem is still ocurring. I guess this is the best way to see if someone has d...

smokinjoe

Rick sorry about the confusion. Yes the radio has three 2030 mosfets installed. The collector voltage on TR51 is 7.6 volts keyed and 3.6 volts unkeyed and i can adjust it up or down with vr13. The gate volts on all three 2030 mosfets is 3.42 volts with radio keyed and 0 volts unkeyed. The drain volt...

smokinjoe

Rick i forgot to mention that i did the pa test and pa is loud and clear. Thanks

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Galaxy Dx 55v no modulation

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