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Author Topic: Faulty TS570DG  (Read 250 times)

AP2RF

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Faulty TS570DG
« on: November 02, 2022, 11:01:59 PM »

Hello
My TS570DG have no RX TX and dots on screen after couple of seconds. Reference 20MHZ fixed and after that frequency is available on the display but still no TX / RX .

Multifunction knob only change KHZ but Main VFO do not work, while rotating its weel, it tries to change HZ frequency but only feel of trying to change but cannot change HZ Fox.  14.000.20, in which 200HZ not change.
VCO 1 , VCO 2 have outputs but no carrier out.  Injected 8.83MHZ from Sig Gen but RX did not work.

I want to know if PLL / DDS still unlock?  kindly guide.

I can send PLL / DDS / RX /TX board for repair, or I can even buy the same working board.

request for kind guidance.

73s / AP2RF


 
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SWMAN

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Re: Faulty TS570DG
« Reply #1 on: November 03, 2022, 05:22:35 AM »

 Did you do a full factory reset on it.
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AP2RF

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Re: Faulty TS570DG
« Reply #2 on: November 03, 2022, 05:46:31 AM »

 so many times, REST.
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W1VT

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Re: Faulty TS570DG
« Reply #3 on: November 03, 2022, 06:03:48 AM »

An unlocked PLL will typically sweep back and forth looking for a lock.  This can easily be seen on spectrum analyzer.  It may be possible to detect the oscillators from stray RF.
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AP2RF

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Re: Faulty TS570DG
« Reply #4 on: November 03, 2022, 07:11:06 AM »

I have no spectrum analyzer. How to check / Verify PLL is unlock? 

Since Main VFO not working / only Multi-Function Knob change KHZ.

while rotating multifunction knob, VCO output changing frequency seen on frequency counter.
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AC2EU

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Re: Faulty TS570DG
« Reply #5 on: November 03, 2022, 07:31:06 AM »

I have no spectrum analyzer. How to check / Verify PLL is unlock? 

Since Main VFO not working / only Multi-Function Knob change KHZ.

while rotating multifunction knob, VCO output changing frequency seen on frequency counter.

Does this happen on one band or all bands? The service manual should have an alignment spec for the VCO lock voltage range.
It seems odd that you are having so many issues with the board, ie; the 20 mhz ref and now a lock issue, etc.

AP2RF

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Re: Faulty TS570DG
« Reply #6 on: November 03, 2022, 12:00:33 PM »

Yes all Bands . no carrier output 8.83mhz as well.
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AP2RF

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Re: Faulty TS570DG
« Reply #7 on: November 10, 2022, 08:24:21 AM »

Hi
Can any body check the voltage @ SO2 Option VCC & REF OSC 20MHZ  .
Service Manual Shows 7.4 to 7.6V on the reference OSC circuitry VCC. whereas in actual it is 4.5 to 4.6V.

While following the same power supply rail coming to REF OSC , it also reach to other ICs showing 4.6volts.

How come it possible, one power line supplying two different voltages?

Kindly check and verify REF OSC 20 MHZ circuitry uses 4.6v or 7.6v .  is that a mistake in service manual?

Help requested . 73s RF

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