Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Hi Leighton, thanks for this, I'm meeting John tomorrow and 'round 2' will definitely look closely at these jumpers and the other suggestions. I've spoken to John and quizzed him as to whether he has made any changes at all, or whether he has lent the rig out and someone else may have made changes. He assures me neither is the case, further, the rig used to work fine on 2 mtrs.
So I'm inclined to the view that we are looking at some component failure. John tells me he may have operated the rig on 2 mtrs with his dual band antenna coax plugged into the 70cms antenna socket. Curses!
Anyway, tomorrow will be a day for STRONG coffee, bacon sarnies and lots of magnified circuit board scrutiny!
Again we appreciate all the helpful comments, FINGERS CROSSED!!!!!
Paul, G0ODP
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of gw3fsp via groups.io Sent: 17 March 2021 06:30 PM To: [email protected]Subject: Re: [YaesuFT847] 2mtr xmit/recv issue - LocOsc Freq Issue Hi Paul, I have just uploaded a file from Yeasu regarding mods to the frequency coverage of the 847. The alterations are done by removing or adding link resistors near to the backup battery. Leighton. GW3FSP. -- This email has been checked for viruses by Avast antivirus software.
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Hi Paul, I have just uploaded a file from Yeasu regarding mods to the frequency coverage of the 847.
The alterations are done by removing or adding link resistors near to the backup battery.
Leighton. GW3FSP.
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The following files have been uploaded to
the Files area of the [email protected] group.
By: gw3fsp <gw3fsp.ldavies@...>
Description:
Band modifications for 847 frequencies
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Look up mods for 847 I remember seeing something about out of band and Mars mods? It's not diodes but chip resistors around back up battery
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Hi Charles, can you tell me which are the ‘band split diodes’, I can’t see any reference to them in the service manual, which board are they on. Thanks again. ? Paul, G0ODP ? ? Check the band split diodes to see if some disabled 144 by accident. They are used to make bands legal in other countries Nope. No error, that 0.5 to 6.5 feeds first The 'low' vco and over 140 The 'high' vco. ? Nils, Dennis, thanks guys, either way this has given us a starting point for tomorrow...... we had given up for today, I needed to spend some time with the wife!!!!!? However tomorrow is another day and this is a GREAT starting point. I will update the group with results. ? Thank you so very much. ? Paul G0ODP ? ? Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
?
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Hi Charles, can you tell me which are the ‘band split diodes’, I can’t see any reference to them in the service manual, which board are they on. Thanks again. ? Paul, G0ODP ?
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From: [email protected] <[email protected]> On Behalf Of charles
Sent: 16 March 2021 19:49
To: YaesuFT847 <[email protected]>
Subject: Re: [YaesuFT847] 2mtr xmit/recv issue - LocOsc Freq Issue? Check the band split diodes to see if some disabled 144 by accident. They are used to make bands legal in other countries Nope. No error, that 0.5 to 6.5 feeds first The 'low' vco and over 140 The 'high' vco. ? Nils, Dennis, thanks guys, either way this has given us a starting point for tomorrow...... we had given up for today, I needed to spend some time with the wife!!!!!? However tomorrow is another day and this is a GREAT starting point. I will update the group with results. ? Thank you so very much. ? Paul G0ODP ? ? Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
?
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Hi Charles, THANKS, I’ll check that as well and let you guys know. I appreciate your support. ? Paul, G0ODP ?
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From: [email protected] <[email protected]> On Behalf Of charles
Sent: 16 March 2021 19:49
To: YaesuFT847 <[email protected]>
Subject: Re: [YaesuFT847] 2mtr xmit/recv issue - LocOsc Freq Issue? Check the band split diodes to see if some disabled 144 by accident. They are used to make bands legal in other countries
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Check the band split diodes to see if some disabled 144 by accident. They are used to make bands legal in other countries
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Nope. No error, that 0.5 to 6.5 feeds first The 'low' vco and over 140 The 'high' vco.
Nils, Dennis, thanks guys, either way this has given us a starting point for tomorrow...... we had given up for today, I needed to spend some time with the wife!!!!!? However tomorrow is another day and this is a GREAT starting point. I will update the group with results. ? Thank you so very much. ? Paul G0ODP ? ? Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Nope. No error, that 0.5 to 6.5 feeds first The 'low' vco and over 140 The 'high' vco.
Nils, Dennis, thanks guys, either way this has given us a starting point for tomorrow...... we had given up for today, I needed to spend some time with the wife!!!!!? However tomorrow is another day and this is a GREAT starting point. I will update the group with results. ? Thank you so very much. ? Paul G0ODP ? ? Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Nils, Dennis, thanks guys, either way this has given us a starting point for tomorrow...... we had given up for today, I needed to spend some time with the wife!!!!!? However tomorrow is another day and this is a GREAT starting point. I will update the group with results. ? Thank you so very much. ? Paul G0ODP ?
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From: [email protected] <[email protected]> On Behalf Of Dennis Surek via groups.io
Sent: 16 March 2021 06:47 PM
To: [email protected]
Subject: Re: [YaesuFT847] 2mtr xmit/recv issue - LocOsc Freq Issue? Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Nils: Did you make a typo error ? I have been reading along. You said .5v to 6.5v? on the lower range and then you said the same voltage .5v to 6.5v on the upper frequency range. There was no change.? 73 de VE3XC
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Re: 2mtr xmit/recv issue - LocOsc Freq Issue
Hi, have you checked the voltage on TP2002 on the PLL board? Shall be between 0.5 an 6.5 from 108 to 139.995 and between 0.5 to 6.5 from 140.000 to 173.995.
The switching of the two vco's is done by Q2015 and Q2016, you should see the switching on TP2004 and TP2005 when passing 139,995.
The signal to Q2015 and Q2016 comes from Q2027 which is controlled by the main CPU on AF-CNTL?
I hope you can follow my thoughts.
Nils
SM7DVO
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2mtr xmit/recv issue - LocOsc Freq Issue
Hi, I am trying to repair an FT847 for a friend, the rig works perfectly on all bands except 2mtrs. On 2mtrs nothing is heard or transmitted; it won’t hear my sig genny at all. I have injected a signal directly into J3001 144RX on the RF Unit and that isn’t heard, I should add that the frequency display is working perfectly. Next I examined the Local Oscillator signal on J3010, we checked this for 70cms (which we knew was working) and could see the signal 45MHz above displayed frequency, all well and good. I then switched to 145MHz and couldn’t find the LO at all on my spectrum analyser. Now this is the ‘fun’ part, when I tuned below 140Mhz, say 139.999MHz a local oscillator signal appeared 45MHz higher, as expected, but would switch off as soon as I reached 140MHz!!!!! We have tried a CPU reset but that didn’t make any difference. Has anyone got any suggestions, we’d really appreciate some inspiration. Sincere thanks. Paul G0ODP, John G0KFM
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Re: FT-847 Optional Filters?
well till a couple weeks ago I needed one??
now I have to get rid of a 2100Hz Inrad
or maybe i will just keep it in the radio disconnected
till some day I want to sound tinny??
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Re: FT-847 Optional Filters?
Is there a market for the original stock muRata filters?? I recently thought I found a Collins YF-115S-02? ssb filter, sent the money, got the package today and found that someone had substituted the Collins filter with the muRata one.? :^(
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Re: FT-847 Optional Filters?
after I install my newly found stock filter (better for FT8 and other digital modes)
I will have a 2100Hz Inrad to rehome??
it currently is in the TX side as that wont bother much for FT8/JS8call and others??
wish there was a 3Khz available
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Re: FT-847 Optional Filters?
Hi Micky,
I can answer one of your questions.? My understanding is the difference between the Inrad and Collins filters is that the Inrad being a crystal filter has a much steeper skirt at the passband edges, thus a much sharper cutoff.? I think they also have a couple more bandwidth options.? And i've seen mentioned a couple of times that the Inrad filters are a bit larger and must be tucked off to the side inside the rig.? See:
I don't have the SSB filters yet but do have a Collins XF-115C cw filter on the way.? What i'm curious about is if two SSB filters are needed. Can one get away with just one in the RX slot?
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The FT847 doesn't have an actual built in SWR meter that I know of?if that's what you are looking for.? According to the copy of the manual that I have, the S meter will show reflected power ONLY when the ATAS-100 antenna is activated. This note is shown in the description of the front panel display. The meter shows the signal strength for receive and either Power Output or Automatic Level Control for transmit. You'll have to have separate SWR meter(s). Most less expensive SWR meters wont work for VHF/UHF. I have one that is selectable between HF and VHF/UHF. Verify the frequency range compatibility before using.??I learned a long time ago to never trust built in SWR meters by themselves.
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Hi All I have been looking in the manual but can find any refence to SWR display.? I have the FC-20 connected but get no indication of SWR reading? Thanks
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For what it is worth. The 70Mhz enabled radios (C2) do not work well without modification.? Approx 12 watts output for 15 amperes current draw, and a very deaf receiver. Add spectral purity on the output signal that includes a signal at 48Mhz only about 4dB down.? The problems appear to be the wrong value of components fiited in filters on the TX side, and the requirement for a pre-amp make it an expensive way to get on 4. A friend of mine weighed it all up, and decided on a transverter from 10 metres, which works considerably better, and easier to implement.
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Hi Micky
?
Ahh! I can see that there is a difference between the U.S. and the U.K model.
Carey W4TFZ pointed out there is no 4mtr band allocation in the U.S.
Thanks for the heads up Carey
?
?
Hey Micky there is only so much aluminium(antennas) a radio tower can hold!
?
?
Paul GW4ZYG
?
Sent from for Windows 10
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From: Micky Corrow via groups.io
Sent: 13 January 2021 01:36
To: [email protected]
Subject: Re: [YaesuFT847] 4mtr info
?
Hi Paul.
My FT-847 does not transmit on 70 MHz. It is a 0M serial, which should place it at November 2000.
After looking at a detailed photo that I took this morning with the bottom cover removed, it appears to be un-modded.?
I did a bit of digging on the Internet and it looks like Keith G4FUF is the master of this particular mod. From his writeup (??) it does not look
really worth it, at least I am not willing to tackle it. If I weigh the risk versus the reward, I don't think there is enough activity here in the NorthEast to justify modding my radio. Then I would need a whole new set of antennas...
Micky K1XH
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gw3fsp
Nils Ostman
Richard
Andy Bosworth
