Concorde 3 channel issues

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Avenger
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Concorde 3 channel issues

Post by Avenger »

Been looking at a tatty old concorde 3 I had part of a job lot a while back and its got a bit of a strange issue ( well to me anyway ). The channel changer seems to skip every other channel as in you'll be on 40, change to 39 and stays on 40 and then does this throughout the rest of the band. The display changes correctly but the frequency stays the same every 2 channels. Any ideas where I could start please?
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PeterA
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Re: Concorde 3 channel issues

Post by PeterA »

I'm no expert, and it's been a long while since I messed about with anything like this to be honest but...

I'd start checking the channel changer board and switch itself, then the ribbon cable from the channel changer to the main board and finish at the PLL itself.

Looking for bad components, bad solder joints, bad/damaged circuit traces etc.

Hope that helps. :thumbup:
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satelitesid
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Re: Concorde 3 channel issues

Post by satelitesid »

Check the pins where channel changer attatches to PCB, if it has one. Other radios have been known to have a crack around solder joints. It sounds like the binary 2 pin isn't talking to PLL
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prettypolly
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Re: Concorde 3 channel issues

Post by prettypolly »

Dont the channels go backwards on low and super low
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Mitch
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Re: Concorde 3 channel issues

Post by Mitch »

The first thing I'd check is pin 15 of the PLL02A. It should change state every channel (more or less), on to off or off to on (0v or 5v), every click, if it doesn't trace it back to the channel changer.
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Avenger
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Re: Concorde 3 channel issues

Post by Avenger »

Thanks all hopefully I'll be back onto it some time tomorrow, I'll let you know what I find.
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Otter
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Re: Concorde 3 channel issues

Post by Otter »

Mitch wrote: 06 Apr 2019, 12:35 The first thing I'd check is pin 15 of the PLL02A. It should change state every channel (more or less), on to off or off to on (0v or 5v), every click, if it doesn't trace it back to the channel changer.
It's not quite so easy with the Concorde/Multimode 3 because there's an inverter / non-inverter resin covered device called HC806 betweer the PLL02 and the channel switch.
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Re: Concorde 3 channel issues

Post by Avenger »

Its 5.15v on every channel on the top 3 bands but 2.15v on both lower bands. Also the radio isn't transmitting or recieving. The 10.240 is there on pin 3 and voltage is ok on tp2 of the vco.
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