Re: If low at O/P then trace back D2016 switching?
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Re: If low at O/P then trace back D2016 switching?
On Sat, Jul 23, 2022 at 6:03 AM Andrew Lenton < a@...> wrote:
Hi the SAT button on and off a few times!
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Hitting the SAT button lights up all the buttons for sat operation. Do hear anything click, but not sure if I am supposed to.
? Check Q2017 is switching as this will kill off the UHF RX and TX LO this should be working as RX is working can you confirm this, tx on a hand held or signal generator
RX is working, confirmed by handheld
Measurements taken:
? D2017 the anodes of the diodes are switched separately for TX and RX, confirm the LO is on cathode of D2016, then follow the LO through the circuit path to the TX LO O/P via Q2039 ?
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? OK TP 4 to TP 7, is the supply to the VCO, pulled on by a PNP transistor in Q2015 to 18. ? OK we have VHF 1 + 2 and UHF 1 + 2, and 4 VCO, I suspect two are for TX and the other two for the RX VCO as they will probably be different frequencies! Or slit frequency operation (not sure here) or when TX and RX are used simultaneously in SAT mode? ?
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73 ? Andrew ? From: Max Donoghue [mailto:ve3tmt@...]
Sent: 22 July 2022 19:34
To: Andrew
Subject: Re: If low at O/P then trace back D2016 switching? ? Went digging into the PLL board. I'm getting 3.66V at TP2003 in TX D2019 is switching as expected, one line high for HF, one for VHF and one for UHF. All three lines tested fine.On the underside of the PLL board, I am getting 7.9V on TP2006, but not TP2007 which leads to Q2018. On UHF I'm getting 7.9V on pin 2 of Q2017 but nothing on pin 2 of Q2018 check if there is something there on RX On VHF I'm getting 7.9V on pin 2 of Q2016 but nothing on pin 2 of Q2015 check if there is something there on RX ? On Fri, Jul 22, 2022 at 1:29 PM Max Donoghue <ve3tmt@...> wrote: Correction to my earlier results, TX IF signal is present on all bands.? TX LO signal is present on all bands except 440. No output there. ? On Fri, Jul 22, 2022 at 7:55 AM Max Donoghue <ve3tmt@...> wrote: No worries I appreciate all the help. ? On Fri, Jul 22, 2022, 7:51 AM Andrew <a@...> wrote: Interesting? ok I am away from home in Torquay, I have limited access to circuits? however? we are nearly there.
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Re: If low at O/P then trace back D2016 switching?
Hi the SAT button on and off a few times! ? Check Q2017 is switching as this will kill off the UHF RX and TX LO this should be working as RX is working can you confirm this, tx on a hand held or signal generator ? D2017 the anodes of the diodes are switched separately for TX and RX, confirm the LO is on cathode of D2016, then follow the LO through the circuit path to the TX LO O/P via Q2039 ? 
? OK TP 4 to TP 7, is the supply to the VCO, pulled on by a PNP transistor in Q2015 to 18. ? OK we have VHF 1 + 2 and UHF 1 + 2, and 4 VCO, I suspect two are for TX and the other two for the RX VCO as they will probably be different frequencies! Or slit frequency operation (not sure here) or when TX and RX are used simultaneously in SAT mode? ? 73 ? Andrew ?
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From: Max Donoghue [mailto:ve3tmt@...]
Sent: 22 July 2022 19:34
To: Andrew
Subject: Re: If low at O/P then trace back D2016 switching? ? Went digging into the PLL board. I'm getting 3.66V at TP2003 in TX D2019 is switching as expected, one line high for HF, one for VHF and one for UHF. All three lines tested fine.On the underside of the PLL board, I am getting 7.9V on TP2006, but not TP2007 which leads to Q2018. On UHF I'm getting 7.9V on pin 2 of Q2017 but nothing on pin 2 of Q2018 check if there is something there on RX On VHF I'm getting 7.9V on pin 2 of Q2016 but nothing on pin 2 of Q2015 check if there is something there on RX ? On Fri, Jul 22, 2022 at 1:29 PM Max Donoghue <ve3tmt@...> wrote: Correction to my earlier results, TX IF signal is present on all bands.? TX LO signal is present on all bands except 440. No output there. ? On Fri, Jul 22, 2022 at 7:55 AM Max Donoghue <ve3tmt@...> wrote: No worries I appreciate all the help. ? On Fri, Jul 22, 2022, 7:51 AM Andrew <a@...> wrote: Interesting? ok I am away from home in Torquay, I have limited access to circuits? however? we are nearly there.
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Indeed we are, I will track the fault down over the weekend? by studying the circuits
73
Andrew
Get
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For those who were following this thread...
I received my Tiny SA signal analyzer yesterday and started checking signals.
https://www.tinysa.org/wiki/
The TX local oscillator signal is present on all bands. The TX IF signal is present on all bands except 440.
Andrew and I are now trying to find out why.
Max
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Hi Max, ? OK you need to check J3006 TX I.F., and J3007 TX LO, they are common to VHF and UHF, The LO is the bit that changes frequency, check it does and the level is the same on VHF and UHF, if all good then Q3002 is looking suspect. ? Not sure of the actual frequencies, or if the LO is higher than the IF or lower, The IF can be 1.8 to 30MHZ, no idea what frequency is used for VHF and UHF say 15MHz, then then the LO would be 425 MHz for 440 MHz ? 73 ? Andrew ? 
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J3008 - TX IF ~ 600mV
Checked D3035 and D3036? both 0.762V one way, nothing the other
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Voltage readings:
J3015 pin 7 (UT8)? 7.83V
J3016 pin 3 (UT8)?? 7.83V
J3011 pin 1 (UHF T8)?? 7.83V
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Hi Everyone, I received the below in my email today.? I hope somene can help the gentilman. :)? I'll give the group first dibs on this, then it'll be going up for grabs on QRZ.com.? Do NOT contact? me unless you have no luck with him.??
?
?
F M (Dan) Daniels?<w5kkq@...>
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to?N4MAV@...,?kubotadan@...
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Russ,
?
This is W5KKQ , Dan Daniels
I am ok in QRZ
?
I saw the Ft847 groups I/O page.? I have an FT847es for sale.
I have Wet?Age-Related?Macular?Degeneration in both eyes.
My right eye is almost blind.I?cannot?read the dials on the?
FT847es. So I had switch to a Flex 5000a so I have a 32" screen.
?
I bought it from a neighbor, KT5U, he bought it new. I have the?original?box,
and packing that came with it. The push button mike that came with it, and?
the 12VDC?power cable that came with it. I have a programing cable that goes with it.
?
It is clean and the box is still?in great?shape. I am asking $750.00. If you will?allow m
to post on the FT847 Groups I/O page or if you post it for me. This is a special radio.
I live near Dallas and looking for some hams interested in AMSAT.
?
Thanks, Russ?for reading this email.
If you think any of the FT847 community will be?interested in this radio
I will send you pictures and the serial number.
kubotadan@...
Best 73's
Dan Daniels
W5KKQ
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Hi when I need help, a thread like this would have been useful. There has also been endless Emails with regards RS232 interfaces!
Ok I will not reply to the group in the future
73
Andrew
Get
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Andrew,
Is it possible D3036 is open? If I am getting output on the VHF side, then the TX IF signal must be present at the anode side of D3035 and D3036.
I've verified Q3014 is switching correctly, pulling D3035 low on VHF TX and D3036 low on UHF TX. But what if?D3036 is bad? The TX IF signal would not pass through, correct?
Max
Next up I'll be checking for 8V on TX at the following points:
J3015 pin 7 (UT8)
J3016 pin 3 (UT8)
J3011 pin 1 (UHF T8)
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Next up I'll be checking for 8V on TX at the following points:
J3015 pin 7 (UT8)
J3016 pin 3 (UT8)
J3011 pin 1 (UHF T8)
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The opening line to the opening page is
"This site exists for the exchange of ideas, advice, technical and general information for the Yaesu Transceiver known as the FT-847."
I would suggest if you find the QRM not to your taste, just spin the dial.?
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Also checked these voltages and all were good 
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Hi All,
Fantastic thread, have been following every exchange, looking forward to the result. Have a non Modded FT847 good luck guys?
¡®73
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On 19 Jul 2022, at 13:26, Andy Bosworth <sidthepop@...> wrote:
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I see no reason why it should be off line. A worthwhile exercise in fault finding,
On Tue, 19 Jul 2022 at 13:21, Max Donoghue < ve3tmt@...> wrote:
Not a problem Ian. I thought others would benefit from the exercise. Sorry to have bothered the group.
I'll continue the repair through private messaging.
If any other members might be interested in the final result I'll post a follow up when repaired.
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Your choice....QRM is optional.
On Tue, Jul 19, 2022, at 20:25, Andy Bosworth wrote:
I see no reason why it should be off line. A worthwhile exercise in fault finding,
On Tue, 19 Jul 2022 at 13:21, Max Donoghue < ve3tmt@...> wrote: Not a problem Ian. I thought others would benefit from the exercise. Sorry to have bothered the group.
I'll continue the repair through private messaging.
If any other members might be interested in the final result I'll post a follow up when repaired.
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I see no reason why it should be off line. A worthwhile exercise in fault finding,
On Tue, 19 Jul 2022 at 13:21, Max Donoghue < ve3tmt@...> wrote: Not a problem Ian. I thought others would benefit from the exercise. Sorry to have bothered the group.
I'll continue the repair through private messaging.
If any other members might be interested in the final result I'll post a follow up when repaired.
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That's great Max, I hope it reaches a resolution.
On Tue, Jul 19, 2022, at 20:21, Max Donoghue wrote:
Not a problem Ian. I thought others would benefit from the exercise. Sorry to have bothered the group.
I'll continue the repair through private messaging.
If any other members might be interested in the final result I'll post a follow up when repaired.
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Not a problem Ian. I thought others would benefit from the exercise. Sorry to have bothered the group.
I'll continue the repair through private messaging.
If any other members might be interested in the final result I'll post a follow up when repaired.
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Andrew Lenton
Andy Bosworth