Galaxy 2517 no tx output

[Chipper]

I have a 2517 that came to me from a friend and said I can hear people fine but I can’t get out to them so I assumed blown final so I first did alignment until Ltd part it will not key up any power on a meter but will show signal on nearby radio. So I pulled the finals and driver and checked them and all are good put them back and changed caps around am regulator they had glue on them and tried again but nothin on am not even able to hear any audio from my monitor radio until I switch to ssb I got audio on the monitor radio but still no power output. The Rex/tx light changes but the meters in the radio don’t show movement or tx but do move freely on receive. Any help will be greatly appreciated thank you

 

[Chipper]

Also I have replaced driver and finals because he still wants them replaced (bought few yrs ago from rf parts they are the good ones) and put in new am regulator, took swing mod out ( diode), put new 945 modulation transistor back in the radio as it was gone, I just am not familiar with these radios and don’t know where to start checking it might be the tx mixer but I’m lost there if someone could explain that to me I have a 30 MHz scope but not a lot of experience using it yet Just tryin to keep the hobby going in our area as we have no local shops to do repairs so at 35yrs old I’m trying to learn how to keep these older gentleman talking to one another. Thanks

 

[nomadradio]

Do you have another radio on hand to listen on the same channel the 2517 is transmitting?

Even better, are you sure the radio is receiving on the right frequency for the channel that's selected?

If not, the transmitter is being disabled by the "lock detector" part of the PLL.

And if you really are on frequency, there should be a weak signal even if the wattmeter won't move when you key the mike. Might have to plug a coax jumper into the monitor radio, thread the shell back down the other end and use the tip of the plug as a "sniffing" antenna. Should hear at least a weak carrier around the transmit-mixer chip IC9.

If you can't there is no reason to molest the power sections of the transmitter. Until you have a drive signal feeding into them, there's nothing for them to amplify.

Makes it sound like your friend is accustomed to dogging the transmitter in his radios until they blow a final or driver, maybe?

The 'scope would tell you where the train is being held up. But the monitor-receiver test can suggest where the 'scope probe should be poked first.

73

 

[Chipper]

Do you have another radio on hand to listen on the same channel the 2517 is transmitting?

Even better, are you sure the radio is receiving on the right frequency for the channel that's selected?

If not, the transmitter is being disabled by the "lock detector" part of the PLL.

And if you really are on frequency, there should be a weak signal even if the wattmeter won't move when you key the mike. Might have to plug a coax jumper into the monitor radio, thread the shell back down the other end and use the tip of the plug as a "sniffing" antenna. Should hear at least a weak carrier around the transmit-mixer chip IC9.

If you can't there is no reason to molest the power sections of the transmitter. Until you have a drive signal feeding into them, there's nothing for them to amplify.

Makes it sound like your friend is accustomed to dogging the transmitter in his radios until they blow a final or driver, maybe?

The 'scope would tell you where the train is being held up. But the monitor-receiver test can suggest where the 'scope probe should be poked first.

73

Thank you and yes with the 2517 on my bird dummy load and my cobra 2000 on my antenna at home I can get a s7 signal on the 2517 but will not show any watts on my 5 or 10 watt slug. No if I put both radios on ssb I get audio but on am it just keys the s7 with no audio. Also the radio receives the locals around here on the right channel just no transmitt

 

[nomadradio]

If you have a 'scope, quickest next test is to put the vertical sensitivity to 2 Volts/div and sweep to 20 mS/cm. Probe the bias-test jumper's surface to see if you have steady DC power in sideband transmit. I'll guess you don't have the 5 Volts DC plus audio in AM mode.

And if you have that, probe the exposed metal tab surface of the driver transistor, then one of the finals. Should see RF on each of those, a carrier in AM and modulated RF in sideband.

And if there's nothing to see at the bias jumper, the modulator transistor Q54 is probably bad.

73

 

[Chipper]

Well the Galaxy 2517 is mine now I traded a working radio for it hope to get back on it later in the week. I changed caps in radio and got a 1/4 watt dead key finally and the am regulator was a diode on the transistor checker so I’m going to go threw that section pulling parts and checking be a long process wish me luck

 

[Chipper]

If you have a 'scope, quickest next test is to put the vertical sensitivity to 2 Volts/div and sweep to 20 mS/cm. Probe the bias-test jumper's surface to see if you have steady DC power in sideband transmit. I'll guess you don't have the 5 Volts DC plus audio in AM mode.

And if you have that, probe the exposed metal tab surface of the driver transistor, then one of the finals. Should see RF on each of those, a carrier in AM and modulated RF in sideband.

And if there's nothing to see at the bias jumper, the modulator transistor Q54 is probably bad.

73

Thanks for this help it’s much needed and very helpful