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 Post subject: Yaesu FT-101
PostPosted: May Wed 02, 2012 2:39 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1411
Location: Eagan, Minnesota, USA
I'm going to put the heavy metal down for a bit and switch to this Yaesu FT-101, serial number
1E 107256.

I got this about a year ago from someone here at work. He said it worked, but drifted. I'm going to see if I can catch up with him and have him fill me in again on what he knows about it.

For starters, is there a common group of parts or things to do when rebuilding one of these rigs?

I have searched the web and have found bits and pieces of information here and there, but nothing comprehensive about rebuilding the FT-101. If anything on a complete rebuild is out there, I'd appreciate the link to it.

I normally do not work with circut boards, but understand that it's important to keep the heat down when replacing parts. Again, any hints on working with circut boards will also be appreciated.

So, any help on this is welcome.

Thanks,
Frank.


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 Post subject: Re: Yaesu FT-101
PostPosted: May Wed 02, 2012 5:30 pm 
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Joined: Nov Tue 18, 2008 8:34 am
Posts: 885
Location: Hutchinson,Kansas
Good source of info.......

http://www.qsl.net/nw2m/ft101.html

A good read on some known problems...

http://www.g3ngd.talktalk.net/yaesu.html


I have a 101E and its a great radio but mine also drifts. It can be on for 24 hours and still drifts. If you find a fix for it let me know.
Theres a cult following of people when it comes to the 101 series of radios. They used to be fairly cheap to buy but anymore are starting to get pricey. The CBers also like them which I think has something to do with the $$$ out there.

Todd

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 Post subject: Re: Yaesu FT-101
PostPosted: May Wed 02, 2012 6:56 pm 
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Joined: Jun Sun 19, 2011 2:31 pm
Posts: 1931
The power supply board (Yaesu may call it the regulator board) should have the electrolytic capacitors replaced if they have not been. They are certainly showing their age by now and they are in a fairly high heat environment.

Clean and lubricate the fan. I think it was optional on some configurations so if your radio doesn't have one add it because the final tubes are expensive and the fan will add to their life. Additional cooling air may also help with the drift. I have a couple of versions of the FT-101 along with the predecessor FTDX-100 and a set of the 101 twins and the drift has never bothered me but my point of comparison for these is similar older radios and not my modern transceivers with TCXO for the master frequency control. When contacting someone who is using a modern rig instead of using RIT to compensate adjust to the other stations frequency during the contact to minimize his need to re-tune. A lot of newer operators have never experienced a rig that drifts so they will be confounded by your drifting if you don't adjust. If you want the FT-101 to masquerade as a modern rig you could use one of the DDS boards to build an external VFO. Or buy the matching FV-101 which will be more stable since it is away from the heat generating components inside the transceiver, it won't be as stable as a DDS but it will have minimal drift after a very short warmup.

Make sure the idle current is properly set and watch it closely for the first few hours of operation. A final tube that is gassy or has secondary emission will cause the idle current to creep up as the tube warms up. If there is any question about whether the final is properly neutralized adjust first on 20 meters to get it close (where it is much less likely to take off into a final destroying oscillation) and then do the final touch up on 10 meters. Tune up must be done rapidly to avoid overheating the finals and it should be loaded to rated input and then you can slightly reduce power (by decreasing drive/audio level) to increase the life of the tubes. The most fragile element in most sweep tubes is the screen grid and light loading will cause excessive screen dissipation followed by rapid tube death. If your version has the built in RF speech processor use it sparingly. It isn't needed under good conditions, the sound quality is somewhat impaired, and it greatly increases the effective duty cycle and heat for the finals which will shorten their life.

Rodger WQ9E


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 Post subject: Re: Yaesu FT-101
PostPosted: May Thu 03, 2012 5:07 am 
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Joined: Jan Sun 23, 2011 2:48 am
Posts: 88
There is a ton of info about the FT rigs here;
http://foxtango.org/foxtango001.htm


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 Post subject: Re: Yaesu FT-101
PostPosted: May Sun 06, 2012 2:48 am 
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Joined: Jun Wed 08, 2011 2:33 am
Posts: 3687
Location: Ohio 45177
You can get alot of info on that FoxTango site. My current FT-101EX was apparently an ex CB as someone had installed the CB crystals in it and it even has the 11M panel markings. I yanked those and they sold easily on ebay. This one is functional. Had the shorted silver mica cap that blows the fuse when you select 160M. Replaced that. The RIT was out of whack but I cleaned the trim pot that you use to zero it and now it is fine. You set the knob to zero and then set the trim pot so there is no freq. shift when you turn it on. Has good finals but I scrounged a backup set of the Japanese finals. Finals are big money. The speech processor is inoperative but it works good without it and a Shure 444 microphone. BTW that 444 is the ideal/best mic for this radio. For the time being it is stored in a plastic bag. Some day I am gonna get it all overhauled to take care of any issues and alignment. Or pay someone to do it. I do not recall drift as being a huge issue with the ones I have had. It is maybe not set and forget all day long stable but not like some old radios. Like tube sets. There used to be extender cards for the PC boards that would allow you to have them up out of the radio for service. Now a rare item. Maybe you could make your own.


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 Post subject: Re: Yaesu FT-101
PostPosted: May Sun 06, 2012 6:53 am 
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Joined: Nov Tue 18, 2008 8:34 am
Posts: 885
Location: Hutchinson,Kansas
Those extender cards are on ebay from time to time and they bring 100$ at least everytime.

I've had my 101E on the last 48 hours...........


Todd


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 Post subject: Re: Yaesu FT-101
PostPosted: May Mon 07, 2012 1:52 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1411
Location: Eagan, Minnesota, USA
The cleaning phase is completed. All module boards are out, fan removed, tubes out, etc.

I think I found a previous problem with the variable capacitor for the Loading control. It sounded like it might be rubbing somewhere, so I removed it. This also let me get in that area and clean the film off of everything. There was a very minor short where one of the outer rotator vanes was slightly hitting the stator. A minor pull fixed that problem. It looked like someone had unsoldered the wires to it, because no other connections in the rig looked like those joints did. There was not enough length of wire to make a nice new connection. This wire looks like it has cloth covering. I replaced it with cloth covered wire from AES, and also placed a sleeve over it. I am guessing that they used this type of wire due to the high voltages in there, and this was the closest that I could come up with.

Next phase will be replacing the electrolytic capacitors that are underneath the chassis. There are about seven of them. I am going to wait and see how the two 100 mfd @ 500 volt capacitors are before I look for replacements for them.

Then on to each module board for electrolytic capacitor replacement.

I have a question about the transistors that are mounted to heat sinks. There are two big ones on the back of the chassis, and two on the audio board. Does the material that is spread on the transistor to heat sink area need to be replaced? If so, what do you use, and where is it purchased from?

_________________
Frank
KD0RUC


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 Post subject: Re: Yaesu FT-101
PostPosted: May Mon 07, 2012 2:02 pm 
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Joined: Jun Sun 19, 2011 2:31 pm
Posts: 1931
Frank wrote:
I have a question about the transistors that are mounted to heat sinks. There are two big ones on the back of the chassis, and two on the audio board. Does the material that is spread on the transistor to heat sink area need to be replaced? If so, what do you use, and where is it purchased from?


Frank,

If those components are disturbed/removed as part of other maintenance then the old compound should be wiped off and new applied. You can get it at Radio Shack: http://www.radioshack.com/product/index ... Id=2102858 or from Mouser or Digikey.

Rodger WQ9E


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 Post subject: Re: Yaesu FT-101
PostPosted: May Tue 22, 2012 1:15 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1411
Location: Eagan, Minnesota, USA
Making progress. The audio board is the only one left to recap. The two 100mfd @ 500 volt capacitors have not been changed. Other than that, all of the electrolytic capacitors have been replaced with 105 degree Nichicons.

I performed a trial run this weekend. I ran it with the filaments on and off alternately for periods of time for a total run time of about ten hours. I had reception on 20, 40 and 80 meters. Not much on the other bands. I'm not using an antenna, just about 20 feet of wire. I'm not sure if I have meter action on the 20 meter band. The signal strength limited by the wire antenna I'm using may be the cause. Not sure yet.

I hooked up a dummy load and did a quick tune test. It does seem ok there. At least no smoke, and the meter does read as you adjust.

So all in all, it's comming along fine. Next will be the audio board. I may leave the two big capacitors alone at this point.

_________________
Frank
KD0RUC


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