Author Topic: Hello. I've just adopted a FT-101  (Read 1372 times)

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Offline mael

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Hello. I've just adopted a FT-101
« on: September 30, 2017, 01:33:00 PM »
Hello.  I am not a pro when it comes to tranceivers.  I  decided to join this forum because someone gave me a Yaesu FT-101.  It's just plain ol' FT-101.  It must be one of the originals.  The person who gave it to me hadn't used it for years and years, and it has been stored in a dry place.  I must admit to being rather clueless and uneducated about radio equipment, and when it came to powering it up, I wasted quite a bit of time because I didn't know what the knobs did.  After a few days I actually had the set receiving some stations with a few metres of wire as an antenna.  I also learned a bit about getting the FT-101 to recieve from Youtube. 

I was slowly getting better at finding stations and started to figure out what the USB/LSB/tune/CW & AM switch was meant for.  Finally I was able to find stations in English and I was becoming more interested and wanted to get it going as well as it could get.  But after a couple of days, I noticed the sound level was dropping, and then the preselect wasn't making any difference in the sharpness of the tuning as it did previously.  As it is now, I can receive  only barely, and the problem doesn't seem to be anything to do with the settings on the front.

My aim is to get it going again.  I figured that as it was working (somewhat) earlier, and that the sound level and radio sensitivity  took a few days to bottom-out, it might be a capacitor or three that gave up the ghost after having electrons whizzing through them after decades of being redundant.  But I don't really know anything.  I thought it was interesting about the preselect formerly working, but now being unresponsive might indicate a specific area or board to check.

I would like some help.  I would be very grateful. The set came with a spare set of output tubes.  I have other radios which pick up SW.  My favourite standby radio is my Sony D2001.  But the 35kg Yaesu is the one I want to use.

I'm not extremely good with electronics, but I'm not totally useless.  I am, however, keen on learning.

Thank you for ploughing through this newbie begging letter.

Offline The Radio Shop

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Re: Hello. I've just adopted a FT-101
« Reply #1 on: October 02, 2017, 07:19:46 AM »
Hello mael and welcome to the forum.
Feel free to post away on your project. We will help where we can.  If you post pictures resize them to large web 640x480.

The 101 is a great radio and not hard to work on.
Looking forward to the repair.
Buddy kc4umo

Offline mael

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Re: Hello. I've just adopted a FT-101
« Reply #2 on: October 03, 2017, 03:26:14 PM »
Thank you for the welcome.   

I've got quite a few things going on at the moment, so I haven't had time to swap some caps - which is what I hope the problem is.  I sometimes go cold when I wonder if it's a component that I can't replace..

Several days ago when it became clear the radio was getting quieter and quieter and apparently less and less sensitive, I reluctantly put it all back together with the aim of digging it out at some time in the future when I  (might) have the time and peace of mind to spend some serious time on sourcing the problem.  Trouble is I never did manage to control myself when it comes to a sickly electronic device that needs fixing.  So after a couple of days I got it back on the bench and fiddled with it some more.

What I've done so far is to clean the switches somewhat - wondering if this might improve matters.  It didn't.  Then I cleaned the relays on the antenna and the one inside the box for the tubes.  Unfortunately this didn't bring it back to life.

I periodically remove the sound board thinking this might be worth re-capping.  I say this because there are a few caps that look dodgy.  The dark browny-red caps appear cracked and split - but not much.  The other caps appear OK.
One reason I haven't replaced even one suspicious looking cap is because I see Yaesu fitted the components properly to the board by bending the wires over before soldering.  That's a bit lazy because I can just use some braid and suck the old solder up then bend the wires straight and replace.

The radio as it is actually works.  It's just at an extremely low level.  I only have a few metres of wire as an antenna, but I was picking up quite a lot before it slowly faded away.  Now, I can get a few whines, and I can detect a voice in the middle of them.
I put a signal into the input of the volume control by way of holding the metal shaft of a pick, and there is certainly some amplification.  I can't say whether it is enough  or not because this radio is a mystery for me - less of a mystery than a week ago, and especially since it gave me a several-hundred volt bite when I erroneously touched some tuning bits just below the protective case of the HV box with my arm when I used it as a resting point.

The FT-101 is on the bench now, and now the case is removed, also the protective covers for the high voltage are off.

I find I spend hours mostly just looking at it and trying to think of where the problem might lie. I certainly want it to work.

I asked an acquaintance who has some tube gear about a professional repair.  He said it wasn't so expensive to ship it, but the repair would likely cost a lot.  I live on a small island and the set would have to be shipped to the mainland. 

Well I'll meander my way back to the bench in a short while and I will ask myself where do I start with changing some caps?  I tried to download the service manual and circuit diagram a few days ago but it was taking forever so I gave up.  But I'll need the circuit diagram if I am going to start swapping bits from the boards.

Offline mael

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Re: Hello. I've just adopted a FT-101
« Reply #3 on: October 04, 2017, 02:59:06 PM »
My goal tonight is to replace at least one cap.

A couple of errors in my above posts bothers me.  One was I said the FT-101 weighed 35kg.  Well it's 35lbs.  The other was the location of a relay inside the enclosure for the output tubes.  It isn't.  Sorry.  I was a bit tired when I posted.  I felt that people who are familiar with the FT-101 would have immediately noticed I was wrong and wondered whether I was actually had an FT-101.

That's all.

Offline Lazarus

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Re: Hello. I've just adopted a FT-101
« Reply #4 on: October 05, 2017, 09:57:40 AM »
My goal tonight is to replace at least one cap.

A couple of errors in my above posts bothers me.  One was I said the FT-101 weighed 35kg.  Well it's 35lbs.  The other was the location of a relay inside the enclosure for the output tubes.  It isn't.  Sorry.  I was a bit tired when I posted.  I felt that people who are familiar with the FT-101 would have immediately noticed I was wrong and wondered whether I was actually had an FT-101.

That's all.
you should be able to edit your own posts, by cliking the "modify" button at the top of the post,

:)

Offline mael

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Re: Hello. I've just adopted a FT-101
« Reply #5 on: October 05, 2017, 02:43:01 PM »
Last night I took out a few caps.  I chose them because they happened to be in the  poorest physical shape.  Unfortunately I see one problem with re-capping as it's virtually impossible to decypher the remnants of the printed values.  If changing those three caps made a difference, it wasn't obvious.  Still the same low output.  Two of the caps I replaced had cracks all around and you could see the film inside.  The other one was physically sound.  I might put the OK looking one back and try to find some more I can change.  I haven't got all that many old boards to get components from these days.  Maybe I should try to order the 'cards' as one unit instead of trying to fix problems within each 'card?'

Not a huge problem though because I am going to try once again to download a circuit diagram and hopefully find something in the service manual which can point me in the right direction to solve the lack of volume and the apparent lack of sensitivity - along with the intriguing lack of proper response when trying to tune in the pre-select.

Hmmm???  Could there be something with the unresponsive pre-select and it's associated circuit?  I just hope it isn't FET because I haven't a clue where I might find one of those and I'm sure it will be a lengthy process to get one.

Well off to go and find something to download.

Yes.  I know I can edit without making a new post.  Actually I hardly ever post anywhere on the 'net, and I only use English here.  It's nice to practice English sometimes.

Offline mael

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Re: Hello. I've just adopted a FT-101
« Reply #6 on: October 06, 2017, 08:38:00 AM »
I downloaded the service manual for the FT-101.  It's  some 221 pages long!  I was sure I clicked the printer options to do it in monochrome but when I looked at the first print I saw it was in colour.  Colour's expensive so my better half is going to want to kick me in the bow lorks twice for that!

I read here and there while the printer was clunking away and I think the manual is nicely written and clear.  Of course I didn't get to any details, but I can see that if I follow the methods explained in it I should eventually be able to fix what's wrong.

I only want to listen to what's out there.  I have no intention of transmitting in the foreseeable future.  So that means there's a lot in the manual I won't need to read - until I get the urge to broadcast.

221 pages!!!   :o

Offline mael

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Re: Hello. I've just adopted a FT-101
« Reply #7 on: October 08, 2017, 02:44:36 PM »
I just wanted to say I've continued this topic in the 'Ham Radio Repair' forum.

If you have any great ideas or hints I'd be pleased to hear them.  But I shall try to find answers on Youtube and elsewhere on this BBS as I go along.

I have the feeling this is mostly a cap problem.  But the caps might have created other issues. I'd so like to send it in for repair by someone who knows the set.  But I will at least try to do it myself.  I'm going at a snail's pace because I don't want to make it even more complicated, but even so I've got at least one 750V shock already!  ;D