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Author Topic: Yaesu FT101 EX no transmit.  (Read 8956 times)
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KK4TYV
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« on: September 17, 2014, 05:02:42 PM »

New to the forum here and also relatively new Ham as well. I have had my Tech for about 2 years now. Anyway I picked up a 101 EX that has no transmit. I have been working on this thing for a few months now and still havent figured it out. I have discovered that it is not getting any RF to the driver tube. All voltages seem to be within spec on the driver and final tubes as well. Just looking for some insight on where to look next. I have been getting some help over at the Fox Tango 101 site on Yahoo. It can be found here https://groups.yahoo.com/neo/groups/FT-101/conversations/topics/8085

Thanks in advance for any insight.

73
KK4TYV
Jeb

Oh yeah the receive is outstanding on this radio. I have been listening to 40 meters for the past month or so. Studying now to get my General.
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kc4umo
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« Reply #1 on: September 18, 2014, 05:34:23 AM »

Very seldom have a seen one with no input to the driver tube.
But to test for this here is a simple way of doing that.

Remove the 12BY7 driver tube.  With another radio or receiver set the VFO t the same frequency.  Listen for a carrier on the receiver and note 2 meter on receiver. Now insert the 12BY7 and let it warm up. Try the procedure again and see if there is an increase in signal and s-meter. This will tell us if the driver stage is working correctly.
Since you have receive on the 101 then we can rule out the VFO and receive tuning circuit.
Depending on the above test will give us an indication of where to go next. My bet is going to be coupling capacitors and missing voltages after the driver stage.
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KK4TYV
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« Reply #2 on: September 18, 2014, 06:39:30 AM »

Ok thanks I will give that a try. Might take me a day or two. I am kinda slow and have limited time to mess with radio related stuff.
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N8ETQ
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Mort


« Reply #3 on: September 18, 2014, 02:36:36 PM »



  Hey Jeb,


        In order of most common problems/confusions
with the hybrid rice box:

  1:  Heater Switch on ?
  2:  Can you see the filaments light ? Verifies Jumper plug on back
  3:  Can you hear the relays trip in MOX?
  4:  About 60ma idle on the PA (Ic) meter in SSB w/ no audio?
   Verifies the presence of HV.

         These 4 checks in addition to the steps Buddy mentioned
should help you figure it out right quick..

GL

Congrats on 1 year OM!

/Dan
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KK4TYV
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« Reply #4 on: September 18, 2014, 04:11:19 PM »



  Hey Jeb,


        In order of most common problems/confusions
with the hybrid rice box:

  1:  Heater Switch on ?
  2:  Can you see the filaments light ? Verifies Jumper plug on back
  3:  Can you hear the relays trip in MOX?
  4:  About 60ma idle on the PA (Ic) meter in SSB w/ no audio?
   Verifies the presence of HV.

         These 4 checks in addition to the steps Buddy mentioned
should help you figure it out right quick..

GL

Congrats on 1 year OM!

/Dan

1. Heaters on
2. Filaments all light up
3. Relays click when using Mox
4. I get 60ma of idle current.

I didnt think about listing those things. Thanks. I hopefully will get to check that out tonight and see where I am with this thing.

Thanks again for the help. I am itching to get this rig working and get my general so I can put it to use.

Jeb
 
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kc4umo
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« Reply #5 on: September 18, 2014, 04:25:41 PM »

Let use know what you find. Dan mentioned some good things to check, I always forget to ask the basics Smiley

They can be pretty decent on AM if you tune em right.  I have 4 of them here and dozens come in for repair.
Good luck on the General. Not hard at all.
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N8ETQ
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Mort


« Reply #6 on: September 18, 2014, 10:36:38 PM »



   Ha Ha Ha,

       It ain't broke man,  well, not seriously anyway.
Typically, one would peak the preselector fer max
RX noise/sig. That may not be the same setting for
Xmit.  If not it needs to be aligned. Did you get a chance
to check Buddy's suggestions? I always check TX's
in CW mode. If they work there, The'll work anywhere.
Even in New Yooork...

Keep us Posted Jeb.. 

Thanks,

/Dan
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KK4TYV
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« Reply #7 on: September 18, 2014, 11:30:00 PM »

I did check it with another 101E and it is not moving the meter on the test radio with or without the driver tube.
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N8ETQ
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Mort


« Reply #8 on: September 19, 2014, 12:22:43 AM »


  Hey Jeb,

       What meter we talkin' bout? Can you Hear the sig
on another Rx? Need to be in "CW" fere this
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KK4TYV
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« Reply #9 on: September 19, 2014, 06:49:13 PM »

The S-meter on the 101E. Ok I was in SSB. I will try CW tonight. Thanks.
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kc4umo
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« Reply #10 on: September 19, 2014, 08:01:37 PM »

Remember, what you are trying to do is hear the sick 101 in the good 101's receiver.

There are components after the driver tube that go south due to heat. This can remove need voltages from the driver stage. If I can get time this week end I will post some diagrams and screen shots to help you locate
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KK4TYV
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« Reply #11 on: September 30, 2014, 04:43:22 PM »

Havent had a minute to work on this thing much lately. Here is what has been replaced in this radio since I got it(should have posted this first).

R-40, R-37, R-5, C-11 those are the ones I replaced. C-13 and C-131 had already been replaced.

Also I have since discovered that the 101E I was trying to use to listen on is deaf as a post. No wonder I couldnt hear anything on it. Probably just gonna save my pennies and send it to Certified Electronics in Atlanta. Only about a 2 hour drive for me so I will probably just take it down there when she tells me she has some time to work on it.

I am still open to suggestions if anyone has any.

73
Jeb
KK4TYV
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