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Galaxy DX-959: No TX or RX!!!

H

HeartbreakHotel

Member
Mar 5, 2011
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Hello everybody,

I just received this Galaxy radio from a friend of mine who needs it repaired. I have all the test equipment needed, but I am unfamiliar with these radios, and would greatly appreciate someone's help.

First, I hooked the radio up to my Astron power supply and powered it on. All of the lights came on as well as the freqeuncy display. However, the receive on this radio is silent. The speaker is working and the RF gain control and squelch were in the correct positions. Next, I hooked it up to a dummy load and tried to transmit. The radio put nothing out and I saw no amperage draw on the power supply.

After reading the service manual, I opened the cabinet for service. I found out that another individual replaced the original output transistors with MOSFETS. The radio has two of them (one for output and one for drive). I unsoldered them and checked them with my multimeter and they tested good.

My next question would be, where should I go from here. As far as I can see, this radio has been peaked and tuned, however, I did not preform the mod and don't know of they did it correctly. However, I don't know if an adjustment could take out the radio's receive.

Thanks for reading and all help is appreciated!!
 

Thanks for the reply. I just hooked a speaker up to the PA port on the rear of the radio and was hearing output. Also, the talkback feature works as well, so the audio chip must be functioning.
 
Just to keep everyone updated, I unsoldered and checked the RF amp transistor for receive (Q17) and it checked ok as an NPN transistor
 
OK now it is time to verify the PLL is not out of lock. this will cause no tx or receive. if you do not have the service manual go to cbtricks.com and they have it there. make sure you have the 10.240 reference at the PLL. it is all in the service manual. I will post a voltage chart for the 69610z board here also so you can check voltages. this will get you started. also does the TX and RX light change colors and does the rf meter show receive. check the vco voltages and make sure it is not to low or to high, this will kill the PLL and give the same symptoms you are getting
 

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  • 69610z board voltages.pdf
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While I am checking voltages, I can answer your questions. When I first power the radio on, the receive light flashes green for a brief moment and then goes out. However, when I transmit, the red TX light stays on like it should. Also, the rf needle does not move off of zero the entire time. The only time it does, is when the switch is set in the MOD position. When I power it on set in this position, the needle will almost peg, but then quicly drop to zero, where it will stay.
 
Also, I would like to mention that when I try to check voltages, the voltage does not stay steady. It quickly reduces to nothing. I was thinking it was due to the capacitors, but I am not totally sure. The postive probe goes to the test point and the negative goes to a ground. I never had this happen before, so I was wondering if I am doing something wrong.
 
Just an update here. Whenever I turn the dimmer pot on the front of the radio, the receive comes in. The RX light glows green and the unit receives. Still no output, but it receives.

Maybe its a voltage problem?
 
killing the PLL is just meaning it does not have the voltages for it to lock the radio into functioning.
some of the things you are now saying makes me think you either have some cold solder joints or some of the plugs have came loose and are not making good connections.
make sure all the connectors are pushed in good and if that does not do it try resoldering the area around the PLL and vco areas and the 10.240 crystal. have you even checked for any voltages at the vco or PLL and if the 10.240 crystal is even working.
 

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