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-   -   Yaesu FT-107M HF Transceiver. Help required please. (https://www.vintage-radio.net/forum/showthread.php?t=49086)

m0bzq-julian 31st Dec 2009 1:29 pm

Yaesu FT-107M HF Transceiver. Help required please.
 
Hi all.

Wonder if anyone can help please? I have just bought a Yaesu FT-107M HF Transceiver which was working fine when I picked it up. However on arriving home I switched it on and the frequency readout is showing 95.xxx.x and appears to be floating around. If I switch to memory mode it shows approximately the band selected and the receiver comes up but switching back to the VFO returns it to the spurious readings and no receive. I wonder if anyone has any idea what could have happened please on the journey from Oxford to Doncaster? The rig was transported right way up and there were no incidents on the journey home.

Sorry but I'm not an electronics expert and am at a loss as to what's happened or where to look for the problem.
Also can anyone recomend someone to take a look at it for me as I really want to use this rig.

Many thanks for any help offered.

Julian.

Station X 31st Dec 2009 1:58 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
It's most likely a dry joint or dirty switch contact. Try cleaning the switch contacts with Servisol first.

Given that the receiver actually dies in VFO mode it's unlikely to be the display chip which is at fault, which is fortunate, as they're difficult if not impossible to get hold of.

If you haven't got a manual you can get one here:-

http://www.mods.dk/manual.php?brand=yaesu

If you need further help it would help if you could post the circuit here.

You say you're not an electronics expert, so perhaps a rig like this is not the ideal one to learn some fault finding skills on.

MichaelR 31st Dec 2009 2:21 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
These are good radio's and a good buy when you get it sorted. I do not know much about them but remember that they had a reputation for the VFO being a bit unstable.

It is proabably something fairly simple to get sorted but If you do not have much experience I would agree with StationX and suggest you find somebody to fix it for you.There are a few members in your area who I think would be more than capable of doing so. It is worth doing and once sorted it should be reliable for you, they have I believe a great receiver.

Mike

m0bzq-julian 31st Dec 2009 2:43 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
Thanks guys.

The frustrating thing is that it was working fine in Oxford so something has gone wrong on the journey home.

I love the old radios and will certainly get it repaired somewhere so if anyone is willing to take a look I'd really appreciate it.

I'm afraid I'm probably the kind of chap you guys don't like as I'm very much a black box operator who is fairly clueless when it comes to repairing.

Hopefully someone will come along who can point me in the right direction?

Cheers,
Julian.

Station X 31st Dec 2009 2:53 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
You're doing the right thing in looking for someone with the right skills to repair your rig.

Can no one in your local Amateur Radio Club help or are they all black box operators too?

We don't mind people admitting they don't have the skills to repair a radio. Far better that, than claiming to have skills and knowledge you don't actually possess and then going on to wreck lovely old technology.

m0bzq-julian 31st Dec 2009 3:01 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
In full agreement, Graham. My thing is more building aerials that work and educating the new licensees at our club not to pay silly money for something that doesn't work as well as 30 bobs worth of wire. (going to do some workshops this summer with them).

I'm not a complete shop egg and have successfully built my own HF all band amplifier using a single 3-500 in grounded grid. Built the case too from 2mm steel plate. I just don't understand electronics very well.

There may be folks at our club who could look at it, I'll ask this week.

Cheers,
Julian.

Sean Williams 31st Dec 2009 5:53 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
Might just be worth popping the covers off, and checking that the screws securing the various boards to the chassis are tight - these really suffered with bad earth issues.

HTH
Sean

dsergeant 31st Dec 2009 6:38 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
This is a symptom of the VFO not oscillating, I experienced similar with my old FT101ZD. Probably as said a dry joint or (more likely) dodgy switch contact, but make sure you have got the switches in the right position - and especially have not selected one of the external VFO options which will do this if you don't have an external VFO fitted.

Dave

m0bzq-julian 31st Dec 2009 7:09 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
hi guys
yeh i checked all the obvious, even pulled all the circuit boards and cleaned/re-installed them but no joy.
beginning to think the mains must be different up here!
seriously tho i'll get some switch cleaner on saturday and give the switches a blast if i can get to them. after that i guess i'll be looking for a repair shop.

David G4EBT 31st Dec 2009 8:26 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
Quote:

Originally Posted by m0bzq-julian (Post 295712)
Thanks guys.

The frustrating thing is that it was working fine in Oxford so something has gone wrong on the journey home.

Hopefully someone will come along who can point me in the right direction?

Cheers,
Julian.

Always worth a quick google Julian! I googled "FT107 faults" and came up with a few bits of info which might help:

First, from: http://www.eham.net/forums/ModsAndRepairs/9621

RE: FT-107M VFO/DISPLAY FAULT
by W9GB on July 4, 2009

Allan - The Yaesu FT-107 is a nice HF transceiver, and I think was the 'first' solid-state PA by Yaesu. They are a bit rare in mint condition. "Pre-DSP/MPU era transceivers" from YAESU FT-101Z / FT-107 / Sommerkamp FT-307 / FT-707 / FT-901, 902 (later version) often made use of a custom integrated circuit (IC), MSM9520RS in their DISPLAY COUNTER UNIT. The bad news is that MSM9520RS is somewhat prone to failures.

Since this particular IC was not a standard product but a custom ordered IC by YAESU and its production has been discontinued for long time. HOWEVER, Teruhiko Hayashi JA2SVZ developed a replacement module using current PIC 16F873 microcontroller and some software programming. http://oh8jep.kotinet.com/ja2svz/ Hopefully the FT-107 VFO module has not been mechanically damaged! w9gb

End quote.

There is a host of free downloads of manuals for amateur radio gear at the rather misleadingly titled link (SCANNERS") here:

http://pdf.textfiles.com/manuals/SCANNERS-S-Z/

Technical info on the FT107:

23 pages (4.1 mB):

More technical info:

http://pdf.textfiles.com/manuals/SCA...hnical%202.pdf

13 pages (2.5mB):

http://pdf.textfiles.com/manuals/SCA...hnical%203.pdf

Ft107 Instruction Manual:

61 pages (11 mB):

http://pdf.textfiles.com/manuals/SCA...n%20Manual.pdf

Hope that helps.

Best of luck!

Regards,

David,
G4EBT.

m0bzq-julian 4th Jan 2010 12:11 am

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
just an update for those who tried to help.
i fixed the rig, it was one of the tiny coaxes which had come off a circuit board so all is well now. it took a magnifying glass and lots of time to find;)

m0bzq-julian 11th Jan 2010 7:29 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
okay so i got the rig working (pretty well too) but i'd now like to do some testing and alignments as per the manual but i think i need a board to plug into the modular sockets to elevate each board to where i can work on them.
i wonder if anyone can advise where i could get such a board please?
thanks
julian

MichaelR 11th Jan 2010 7:43 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
Probably a shop that specialises in hen's teeth ;D

Seriously, might be worth a look on Ebay , a few items appear there from people "parting" old units. You might be able to make your own extender card from an old module.

Mike

Station X 11th Jan 2010 10:03 pm

Re: Yaesu FT-107M HF Transceiver. Help required please.
 
You may be able to make an extender so long as the boards plug into a standard type of edge connector.


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