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  1. YaesuFT847
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Expanded Topics Messages
Date
Re: Schematics?

 

Ok some don't, check the input first, you really do need a small spectrum analyser, some SMA flying leads and some SMA attenuators and perhaps a USB power meter?

But I will help you all I can from a distance,

73

Andrew G8UUG look me up on QRZ

Get

Re: Schematics?

Max Donoghue
 

According to the NEC datasheet, the pinout matches the schematic.
Re: Schematics?

 

You have to check it is the right pin out pin 7 and 8 are interchange on the NEC version

Get

Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

Max Donoghue
 

I've got a couple on order now just in case it turns out to be the issue. Sure would have been nice if they were socketed.?

I'll check those other two test points tonight and report back.

Thank you again for the the help.
Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

 

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found one for a few quid

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 17:37
To: Andrew Lenton
Cc: [email protected]
Subject: Re: [YaesuFT847] Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

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Pin 8 was showing about 4.1V

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On Mon, Jul 18, 2022 at 12:34 PM Andrew Lenton <a@...> wrote:
Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

Max Donoghue
 

Correct, it is labelled a "KEY" line in the schematic.
Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

 

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Found it

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Pin 8 is supply

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73

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Andrew

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 17:37
To: Andrew Lenton
Cc: [email protected]
Subject: Re: [YaesuFT847] Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

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Pin 8 was showing about 4.1V

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On Mon, Jul 18, 2022 at 12:34 PM Andrew Lenton <a@...> wrote:

REN_P12448EJ3V0DS00_DST_19981101.pdf
REN_P12448EJ3V0DS00_DST_19981101.pdf

Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

 

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Hi This is a high gain amp see spec

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73

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Andrew

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 17:37
To: Andrew Lenton
Cc: [email protected]
Subject: Re: [YaesuFT847] Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

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Pin 8 was showing about 4.1V

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On Mon, Jul 18, 2022 at 12:34 PM Andrew Lenton <a@...> wrote:

UPC1677_NEC.pdf
UPC1677_NEC.pdf

Re: Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

Max Donoghue
 

Pin 8 was showing about 4.1V

On Mon, Jul 18, 2022 at 12:34 PM Andrew Lenton <a@...> wrote:
Check Pin 8 gets its supply either 5V 8v or 12V or raw 13.8

 

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Re: Schematics?

Max Donoghue
 

Will do, have to check those tonight.
Re: Schematics?

 

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Check TP 3009 UHF switch on and VHF switch on TP3010

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 17:23
To: [email protected]
Subject: Re: [YaesuFT847] Schematics?

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Hi Andy

On J3005 (VHF) I was getting about 1.4V, on J3006 I was only seeing about 43mV.

These measurements were taking of the output pin (pin 5) of each UPC1677C feeding J3005 and J3006.?

Re: Schematics?

 

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Also check TP 3009 below, should go low on TX, it pulls D3035 and D3036 on so the RF signal can pass through

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73

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Andrew

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 13:44
To: [email protected]
Subject: Re: [YaesuFT847] Schematics?

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Correct, as crude as it is!

Re: Schematics?

Max Donoghue
 

Hi Andy

On J3005 (VHF) I was getting about 1.4V, on J3006 I was only seeing about 43mV.

These measurements were taking of the output pin (pin 5) of each UPC1677C feeding J3005 and J3006.?
Re: Schematics?

 

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Measure J3005 and J3006 let me know what you get

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From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 18 July 2022 13:20
To: [email protected]
Subject: Re: [YaesuFT847] Schematics?

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Comparing the output of Q3002 to Q3007 on the UHF side (both of the RF board) I'm seeing about 1.4V out of Q3002 pin 8, whereas I'm only seeing about 43mv out of Q3007 on pin 8.

I see RF Parts has the UPC1677 in stock, but there is a $15 min order requirement and then $41 to ship. Nuts.

Re: Schematics?

Max Donoghue
 

Correct, as crude as it is!
Re: Schematics?

 

Let me check and get back? these voltages are on your RF probe right?

Get

Re: Schematics?

Max Donoghue
 

Comparing the output of Q3002 to Q3007 on the UHF side (both of the RF board) I'm seeing about 1.4V out of Q3002 pin 8, whereas I'm only seeing about 43mv out of Q3007 on pin 8.

I see RF Parts has the UPC1677 in stock, but there is a $15 min order requirement and then $41 to ship. Nuts.
Re: Schematics?

Max Donoghue
 

All the adjustments look to be within spec. I had a look at Q3007 (UPC1677C) I compared the readings against Q3011 and I am getting nothing on pin 5 of Q3007. I am getting just over 4V on the KEY line, pin 8.

Perhaps Q3007 is bad. Isn't this the same predriver ICOM used in the 746 and 756 series radios? Lots of them went south. I don't think you can get these anymore.

Max
Re: Schematics?

 

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True we can deal with this later

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73

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Andrew

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From: [email protected] [mailto:[email protected]] On Behalf Of Spence M0STO via groups.io
Sent: 17 July 2022 20:05
To: [email protected]
Subject: Re: [YaesuFT847] Schematics?

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That’s probably the radio off! 5ppm x 145 on 2m or 725hz and 5ppm x 433mhz for 70cm is 2.165khz.

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? I would say your radio is in spec in FM.

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De Spence M0STO?

Sent while portable! please excuse typos.


On 17 Jul 2022, at 19:40, Max Donoghue <ve3tmt@...> wrote:

Hi Andy,

also notice when listening to the local repeaters, the discriminator reading on the meter is off to the left. I actually have to tune about 1.5 KHz above the repeater output if I wanted to center it. Not sure if something is out there either.

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