Faults with a Ham international Multimode 2

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Raverrst
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Faults with a Ham international Multimode 2

Post by Raverrst »

Hi guys. As in title I’ve a Ham international multimode 2 PTBM059COX board, bought as none working, someone had converted it to 10meters as the crystals had been changed, iv bought a 2nd sub board fitted the correct crystals, started doing the alignment and I can’t get the vco voltage to adjust down (4.6volts beleave it should be 3.6volts) ajusting the core makes no difference to the voltage at all, iv changed the vco but still no change? The Rig will tx on all three bands but only on one frequency and this rafts badly! Channel changer makes little to differents, any thoughts guys.. thanks for any help..
☢️Wednesday’s and Sunday’s 9pm 27.405 Usb, Qsk’s welcome☢️
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cb4ever104
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Re: Faults with a Ham international Multimode 2

Post by cb4ever104 »

I don't usually work on cybernet stuff , but it seems pretty clear that your VCO isn't locked . You say you changed the crystal board . Have you checked the output of that to make sure that you're getting the correct frequency ?
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
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Raverrst
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Re: Faults with a Ham international Multimode 2

Post by Raverrst »

Hi.. haven’t changed the whole board, I’ve replaced the vco, changed capacitor c11 as there prone to fail, checked all the test point frequencies and there all spot on, I’m thinking it’s the pll at fault which I have a spare on the board 🤔
☢️Wednesday’s and Sunday’s 9pm 27.405 Usb, Qsk’s welcome☢️
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cb4ever104
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Re: Faults with a Ham international Multimode 2

Post by cb4ever104 »

Was the radio working when it was on 10m ?
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
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Raverrst
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Re: Faults with a Ham international Multimode 2

Post by Raverrst »

No, was doing the same with the 10 meter crystals..
☢️Wednesday’s and Sunday’s 9pm 27.405 Usb, Qsk’s welcome☢️
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cb4ever104
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Re: Faults with a Ham international Multimode 2

Post by cb4ever104 »

Well , it's a closed loop circuit . So if you're happy with the 10.240 , Loop oscillator , and the VCO , then I'd try changing the PLL .

Sammy
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
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