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  1. YaesuFT847
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No TX or RX

Wayne Carpenter KN2Z @minicowman
 

Howdy.? First off, I'm a vintage radio tech.. tubes (valves?) are my favorite things to work on.
However, I have a friend & neighbor that has an FT-847 that he asked me to take a look at.
Here's what I found as far as symptoms:
?
1. No AM at all. No TX, no RX, no reaction to PTT. Dead silent.
2. Radio is deaf on all bands. Zero receive. There is static but broadcasting a +3db signal in my shack (via my HP 8656B generator on each of the modes the radio can do, zero signal detected. At +3db, neighbors a block away should pick it up.)
3. No TX on any band or mode except FM.
? 3.a. TX function is activated with PTT however, there is no modulation in any mode.
? ? ? ?(This was verified both via the supplied microphone as well as injecting an audio signal into the mic jack)
? 3.b. FM appears to have full power (I saw 40 watts on the meter.. I didn't check to see if this was a menu setting or just max for FM.)
4. CW mode checked. (plugged in a straight key I use on other radios).. Internal keyer functions and moves radio into TX however, no power from finals.
I did do the master CPU reset (held <FAST> and <LOCK> while powering up the unit. No change to listed symptoms.
?
This is really about the extent of my testing ability with the equipment I have.? So here are two questions:
?
1. Do any or all of these symptoms sound familiar to anyone here?
2. Recommendations for someone qualified to dig into this radio?? I got ripped off on an Icom repair by an alleged radio tech some years ago and I'm pretty gun-shy when it comes to sending a radio to someone so solid recommendations are appreciated.
?
Thanks all!
?
73
?
WC/KN2Z
 

Is there any RX on FM with a known signal?


On Tue, 23 Jul 2024, 18:44 Wayne Carpenter KN2Z @minicowman via , <mwcarpe=[email protected]> wrote:

Howdy.? First off, I'm a vintage radio tech.. tubes (valves?) are my favorite things to work on.
However, I have a friend & neighbor that has an FT-847 that he asked me to take a look at.
Here's what I found as far as symptoms:
?
1. No AM at all. No TX, no RX, no reaction to PTT. Dead silent.
2. Radio is deaf on all bands. Zero receive. There is static but broadcasting a +3db signal in my shack (via my HP 8656B generator on each of the modes the radio can do, zero signal detected. At +3db, neighbors a block away should pick it up.)
3. No TX on any band or mode except FM.
? 3.a. TX function is activated with PTT however, there is no modulation in any mode.
? ? ? ?(This was verified both via the supplied microphone as well as injecting an audio signal into the mic jack)
? 3.b. FM appears to have full power (I saw 40 watts on the meter.. I didn't check to see if this was a menu setting or just max for FM.)
4. CW mode checked. (plugged in a straight key I use on other radios).. Internal keyer functions and moves radio into TX however, no power from finals.
I did do the master CPU reset (held <FAST> and <LOCK> while powering up the unit. No change to listed symptoms.
?
This is really about the extent of my testing ability with the equipment I have.? So here are two questions:
?
1. Do any or all of these symptoms sound familiar to anyone here?
2. Recommendations for someone qualified to dig into this radio?? I got ripped off on an Icom repair by an alleged radio tech some years ago and I'm pretty gun-shy when it comes to sending a radio to someone so solid recommendations are appreciated.
?
Thanks all!
?
73
?
WC/KN2Z
 

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Hi you have a TX VCO out of lock, I will look it up for you it is easy to get it going, if affect SSB and CW only

?

73

?

Andrew

?

From: [email protected] <[email protected]> On Behalf Of Andy Bosworth
Sent: 23 July 2024 19:08
To: [email protected]
Subject: Re: [YaesuFT847] No TX or RX

?

Is there any RX on FM with a known signal?

?

On Tue, 23 Jul 2024, 18:44 Wayne Carpenter KN2Z @minicowman via , <mwcarpe=[email protected]> wrote:

Howdy.? First off, I'm a vintage radio tech.. tubes (valves?) are my favorite things to work on.

However, I have a friend & neighbor that has an FT-847 that he asked me to take a look at.

Here's what I found as far as symptoms:

?

1. No AM at all. No TX, no RX, no reaction to PTT. Dead silent.
2. Radio is deaf on all bands. Zero receive. There is static but broadcasting a +3db signal in my shack (via my HP 8656B generator on each of the modes the radio can do, zero signal detected. At +3db, neighbors a block away should pick it up.)
3. No TX on any band or mode except FM.
? 3.a. TX function is activated with PTT however, there is no modulation in any mode.
? ? ? ?(This was verified both via the supplied microphone as well as injecting an audio signal into the mic jack)

? 3.b. FM appears to have full power (I saw 40 watts on the meter.. I didn't check to see if this was a menu setting or just max for FM.)
4. CW mode checked. (plugged in a straight key I use on other radios).. Internal keyer functions and moves radio into TX however, no power from finals.

I did do the master CPU reset (held <FAST> and <LOCK> while powering up the unit. No change to listed symptoms.

?

This is really about the extent of my testing ability with the equipment I have.? So here are two questions:

?

1. Do any or all of these symptoms sound familiar to anyone here?

2. Recommendations for someone qualified to dig into this radio?? I got ripped off on an Icom repair by an alleged radio tech some years ago and I'm pretty gun-shy when it comes to sending a radio to someone so solid recommendations are appreciated.

?

Thanks all!

?

73

?

WC/KN2Z
Wayne Carpenter KN2Z @minicowman
 

No. Nothing heard.
?
My HP generator does a good job of either AM or FM modulation and I had tested both functions on my Kenwood TS-590sg a few days ago.
?
But in this case I couldn't hear a signal at all and the S meter didn't move on RX.
?
I even tuned around a bit up and down in case the reference frequency had gone south but never found any signal.
?
One other test I did.. on 2m, I keyed up my Yaesu FT-50r on one of the local repeater frequencies and listened for anything on the 847. Again, tuning up and down almost 1 mhz each way.. Nadda.
?
I also took the unit off of the dummy load and connected it to my 6BTV in the back yard.. Setting the radio to FT8 frequencies (both 40m and 20m).. nothing heard other than standard white noise.
?
I fear that his radio may be not worth repairing.. but, not my radio and I'm not able nor willing to make a call like that.
 

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Try this:

?

?

Failing that go through all the alignment.

?

73

?

Andrew

?

?

From: [email protected] <[email protected]> On Behalf Of Andy Bosworth
Sent: 23 July 2024 19:08
To: [email protected]
Subject: Re: [YaesuFT847] No TX or RX

?

Is there any RX on FM with a known signal?

?

On Tue, 23 Jul 2024, 18:44 Wayne Carpenter KN2Z @minicowman via , <mwcarpe=[email protected]> wrote:

Howdy.? First off, I'm a vintage radio tech.. tubes (valves?) are my favorite things to work on.

However, I have a friend & neighbor that has an FT-847 that he asked me to take a look at.

Here's what I found as far as symptoms:

?

1. No AM at all. No TX, no RX, no reaction to PTT. Dead silent.
2. Radio is deaf on all bands. Zero receive. There is static but broadcasting a +3db signal in my shack (via my HP 8656B generator on each of the modes the radio can do, zero signal detected. At +3db, neighbors a block away should pick it up.)
3. No TX on any band or mode except FM.
? 3.a. TX function is activated with PTT however, there is no modulation in any mode.
? ? ? ?(This was verified both via the supplied microphone as well as injecting an audio signal into the mic jack)

? 3.b. FM appears to have full power (I saw 40 watts on the meter.. I didn't check to see if this was a menu setting or just max for FM.)
4. CW mode checked. (plugged in a straight key I use on other radios).. Internal keyer functions and moves radio into TX however, no power from finals.

I did do the master CPU reset (held <FAST> and <LOCK> while powering up the unit. No change to listed symptoms.

?

This is really about the extent of my testing ability with the equipment I have.? So here are two questions:

?

1. Do any or all of these symptoms sound familiar to anyone here?

2. Recommendations for someone qualified to dig into this radio?? I got ripped off on an Icom repair by an alleged radio tech some years ago and I'm pretty gun-shy when it comes to sending a radio to someone so solid recommendations are appreciated.

?

Thanks all!

?

73

?

WC/KN2Z
Wayne Carpenter KN2Z @minicowman
 

On Tue, Jul 23, 2024 at 03:34 PM, Andrew Lenton wrote:
Failing that go through all the alignment.
Thanks Andrew!? I will give the voltage check a try. Sounds easy enough.??
?
I don't know about an alignment though. I have a user manual and schematics that I downloaded but I don't have anything like an advanced or service manual so no alignment instructions.? I have a recently calibrated HP signal generator, an Agilent spectrum analyzer and a couple of scopes that do well enough for HF band work (one's a 25MHz and the other is a 50) but doing an alignment on one of these vs an old National or Hallicrafters seems a bit daunting without proper instruction.
?
But I will try what you've suggested. I really want to help the guy out. He's always doing stuff for others and volunteers in the community all the time. It would be nice to give back now and then.
 

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Hi there are a number of simple alignment steps, where the test point are peaked even with out much test equipment you can do around 80%

?

Q1024 is a VCO locked to X1001 the component drifts over the years.

?

I have known hams that when doing an alignment, accidently, move the wrong coil so make sure you find T1009 as it has many neighbours. There are manuals on this forum you can down load

?

73

?

Andrew

?

?

From: [email protected] <[email protected]> On Behalf Of Wayne Carpenter KN2Z @minicowman via groups.io
Sent: 24 July 2024 14:23
To: [email protected]
Subject: Re: [YaesuFT847] No TX or RX

?

On Tue, Jul 23, 2024 at 03:34 PM, Andrew Lenton wrote:

Failing that go through all the alignment.

Thanks Andrew!? I will give the voltage check a try. Sounds easy enough.??

?

I don't know about an alignment though. I have a user manual and schematics that I downloaded but I don't have anything like an advanced or service manual so no alignment instructions.? I have a recently calibrated HP signal generator, an Agilent spectrum analyzer and a couple of scopes that do well enough for HF band work (one's a 25MHz and the other is a 50) but doing an alignment on one of these vs an old National or Hallicrafters seems a bit daunting without proper instruction.

?

But I will try what you've suggested. I really want to help the guy out. He's always doing stuff for others and volunteers in the community all the time. It would be nice to give back now and then.
Wayne Carpenter KN2Z @minicowman
 

I got the radio opened up this morning and finally located both TP1003 and the T1009 adjustment.
?
It looks as though someone has 'technified' this rig before I got to it. I found a single copper-coated spring steel 'finger' like one finds on radios that ensure the case is grounded to chassis ground. But just one.. and nowhere else in the radio were any like it and no place that looked like one or more had broken away.
?
I found there to be? 0.07 vdc on TP1003 regardless of state of RX or TX.. no change. This was with CW mode selected and RF power turned all the way down. I tried to bring pwr up to see what might happen with the voltage at TP1003.. While the radio still shows going into TX mode, no power is displayed on the S/PWR meter on the radio and none on the wattmeter I had between the radio and the dummy load.? And the voltage remained unchanged regardless of RF pwr control setting.? Then I discovered that the T1009 control was already maxed out (fully clockwise). I tried backing it off and the voltage at TP1003 decreased from 0.07 all the way down to 0.00.
?
I can hear the relay click on TX but still not even a flutter in voltage.?
?
I just get the feeling the problem is a lot deeper than a VCO adjustment. I'm still open to suggestions but I'm about ready to give him the bad news.? If he can find someone honest, that works on these things for a living, he might still be okay with it but it doesn't appear that I'm the guy for the job. I'm a hobby-level tech that works almost exclusively on old/vintage tube gear. If I HAD a pay grade, this would be above it?
?
WC/KN2Z
 

I would check to see if your reference oscillator is even oscillating.? Do you see 45.250 MHz on TP1002?
?
You said it transmits in FM.? Just because there is RF showing on a Wattmeter does not mean it's the correct one.? Check to see if it is actually transmitting on the frequency the radio is set to.
?
As someone else mentioned, go through the alignment procedure.? When starting out repairing radios it is often the best diagnostic tool.? You will be probing and adjusting pretty much every circuit throughout the radio.? If you get to a point in the alignment where something is wrong work your way back through that circuit.
?
Mike KC3OSD
 

Here here, these radios do drift over time

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On 26 Jul 2024, 20:52, at 20:52, Mike KC3OSD <micbial@...> wrote:
I would check to see if your reference oscillator is even oscillating.?
Do you see 45.250 MHz on TP1002?

You said it transmits in FM.? Just because there is RF showing on a
Wattmeter does not mean it's the correct one.? Check to see if it is
actually transmitting on the frequency the radio is set to.

As someone else mentioned, go through the alignment procedure.? When
starting out repairing radios it is often the best diagnostic tool.?
You will be probing and adjusting pretty much every circuit throughout
the radio.? If you get to a point in the alignment where something is
wrong work your way back through that circuit.

Mike KC3OSD
Wayne Carpenter KN2Z @minicowman
 

On Fri, Jul 26, 2024 at 02:52 PM, Mike KC3OSD wrote:
I would check to see if your reference oscillator is even oscillating.? Do you see 45.250 MHz on TP1002?
Huge amount of noise on TP1002. But I was eventually able to sync on a signal that was nearly double the expected 45-ish MHz.. More like 76 MHz.?
?
I appreciate all the input and suggestions. Truely. But at this point I am putting it back together and handing it back to the owner along with my best wishes.
?
73 y'all.
?
WC/KN2Z
 

Sounds like it is weak and noisy

Need a spectrum analyser

73

Andrew

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On 28 Jul 2024, 00:23, at 00:23, "Wayne Carpenter KN2Z @minicowman via groups.io" <mwcarpe@...> wrote:
On Fri, Jul 26, 2024 at 02:52 PM, Mike KC3OSD wrote:


I would check to see if your reference oscillator is even
oscillating.? Do
you see 45.250 MHz on TP1002?
Huge amount of noise on TP1002. But I was eventually able to sync on a
signal that was nearly double the expected 45-ish MHz.. More like 76
MHz.

I appreciate all the input and suggestions. Truely. But at this point I
am putting it back together and handing it back to the owner along with
my best wishes.

73 y'all.

WC/KN2Z

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