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Galaxy DX 959B Deluxe Edition is transmitting off frequency on AM
- Thread starter Logi345
- Start date
Or did you mean Channel 3.... which is 26.985?
The reason I pick THAT one is 26.985 - 26.527 is 458 KHz.....which is VERY CLOSE to the 455 KHz IF .
That would sound to me like there is a TX/RF shift in the PLL/VCO that is either "stuck on" or "doesn't work at all"..... so you are 455 KHz DOWN from where you should be.
Do you have another radio that you can key on....and see what channel you are receiving on? Like set the other on channel 3 and key it....and make sure THIS radio hears it on the right channel.
Since it is down shifting on transmit... you may want to test on a higher Channel 23 or 40 so that you have some room to drop if you have to go find it.
The reason I pick THAT one is 26.985 - 26.527 is 458 KHz.....which is VERY CLOSE to the 455 KHz IF .
That would sound to me like there is a TX/RF shift in the PLL/VCO that is either "stuck on" or "doesn't work at all"..... so you are 455 KHz DOWN from where you should be.
Do you have another radio that you can key on....and see what channel you are receiving on? Like set the other on channel 3 and key it....and make sure THIS radio hears it on the right channel.
Since it is down shifting on transmit... you may want to test on a higher Channel 23 or 40 so that you have some room to drop if you have to go find it.
I used my Kenwood TS 940S to receive and that is the frequency that it was broadcasting on. I’m thinking IC3 the “phase lock Loop” PLL is malfunctioning...
Then it would in every mode, not just AM. I'm thinking there is a bad solder joint in the AM path to the pllI used my Kenwood TS 940S to receive and that is the frequency that it was broadcasting on. I’m thinking IC3 the “phase lock Loop” PLL is malfunctioning...
Boy - I gotta buy you guys a beer sometime ...
My only input I can provide is to check and verify that J14 is properly aligned and SEATED - else D85/D86 D87 steering diode mess to route the proper Switch toggling to make sure AM is being detected as the mode it is in.
IF the PLL doesn't see that RX/TX switch - the 8719 is thinking it's something else.
So to me this is related to the VCO side that AM mode plus TX mode - needs to RF switch-in a cap to change the IF (Revert) frequency to kill the 455kHz IF 2nd IF. Thats on the RX line...you get RX so that rules that out.
D97 and D98 turn on the Q47 IF stuff for TX - so if TX mode isn't turning on in AM - steering diodes may be the culprit.
My only input I can provide is to check and verify that J14 is properly aligned and SEATED - else D85/D86 D87 steering diode mess to route the proper Switch toggling to make sure AM is being detected as the mode it is in.
IF the PLL doesn't see that RX/TX switch - the 8719 is thinking it's something else.
So to me this is related to the VCO side that AM mode plus TX mode - needs to RF switch-in a cap to change the IF (Revert) frequency to kill the 455kHz IF 2nd IF. Thats on the RX line...you get RX so that rules that out.
D97 and D98 turn on the Q47 IF stuff for TX - so if TX mode isn't turning on in AM - steering diodes may be the culprit.
This is a DX949, but it's the same board. I highlighted the parts that H.A. mentioned so you'll know were to look. 
Oh, sorry for the "Buy you guys a Beer" moment...
I was referring to Non-Alcoholic
Back to the purpose...
I was referring to Non-Alcoholic
Back to the purpose...
- I was referring to how quickly they (Forum Members) were guiding you to correct the problem and did this is such a great way that if they had been my kids, I would have had that moment in front of the campfire to have that "Talk" - that moment of happy yet sad, when Dad realizes his progeny is growing up and The Dad no longer needed (sigh) Required, yes, Useful? Certainly. But no longer needed as a form of training - now more of a coach - the shift from "If it were me I'd do this" to "Ok, what would YOU do?"
Speaking ONLY for myself...... absolutely NO OFFENSE TAKEN.
Only excitement was felt!!!!
Only excitement was felt!!!!
Actually @guitar_199 I am honored by your response to this gentleman's question.
By how WELL you answered it - for many don't think about the "How" the radio works, just the "Why".
By how WELL you answered it - for many don't think about the "How" the radio works, just the "Why".
Another thing to note that could possibly be connected with this problem. When I connect my frequency counter or oscilloscope to TP 5 to check the frequency I get nothing unless I unhook the ground on the probe then the frequency bounces around all over the place but nowhere close to where it is supposed to be. My equipment is going through an isolation transformer and the radio is being powered off of a battery.
Or...
You're missing a Kill Signal from an RF switch to kill 10.240 / 455kHz = 10.695...
It's why I mentioned J14 being seated, if it is seated and working correctly, then the 455kHz SHIFT you're seeing is from a 10.695 versus 10.240 mishap between TX and RX modes - in AM.
It's why I mentioned J14 being seated, if it is seated and working correctly, then the 455kHz SHIFT you're seeing is from a 10.695 versus 10.240 mishap between TX and RX modes - in AM.
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