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Author Topic: FT-101E No 160 meter power out and very poor recieve  (Read 465 times)

AD4U

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FT-101E No 160 meter power out and very poor recieve
« on: October 09, 2021, 07:46:48 AM »

I bought this FT-101E as a project. After some repairs it works perfectly on 80-10 meters. Power out is 100+ watts and the receiver can easily hear a -120dB carrier from my HP 8640B. Reports on the air are all good.

Problem is on 160M there is NO power out and on 160M receive is very deaf. Putting a 160M signal into the antenna SO239, it takes a very strong signal (-30dB) from my 8640B just to barely hear the signal in the speaker. However when I active the 100 / 25 KHz calibrator when the band switch is in the 160M band the calibrator signal is S9-40 on the S meter and the receiver on 160M seems to have full sensitivity.

That tells me that there is a problem only on 160M from the SO239 antenna connector to where the 100 / 25 KHz calibrator signal is injected into the receive chain.

I cleaned the relay, but that did not help. The same relay sends receive signals to ALL BANDS from the SO239 into the receiver, so I really do not think the relay was the problem.

Since this FT-101E has the AM filter, I wonder is it was on the CB band at one time. However there are no indications that the rig had been abused by too much AM carrier or in the CB band.

My 72 year old eyes cannot locate a problem in or around the band switch near the SO239.

Any ideas will be appreciated.

Thanks and 73

Dick AD4U
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AC2EU

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #1 on: October 09, 2021, 08:09:12 AM »

Some possibilities:
dirty bandswitch
dead or missing heterodyne xtal for 160 M
misaligned stages for that band
RF

AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #2 on: October 09, 2021, 09:00:19 AM »

Some possibilities:
dirty bandswitch
dead or missing heterodyne xtal for 160 M
misaligned stages for that band
RF

Thanks for the reply. The band switch has been cleaned. The 160M crystal is oscillating. I tried several times to align the 160M stages with no improvement.

The receiver works but is very deaf when a signal is at the SO239 antenna connector on the rear of the rig.  The receiver works normally when I activate the 100/25 KHz calibrator. The 100/25 KHz calibrator output is fed into the receiver chain just after the SO239 antenna input. Zero RF out.
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AC2EU

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #3 on: October 09, 2021, 10:03:15 AM »

Quote
Thanks for the reply. The band switch has been cleaned. The 160M crystal is oscillating. I tried several times to align the 160M stages with no improvement.

The receiver works but is very deaf when a signal is at the SO239 antenna connector on the rear of the rig.  The receiver works normally when I activate the 100/25 KHz calibrator. The 100/25 KHz calibrator output is fed into the receiver chain just after the SO239 antenna input. Zero RF out.

The calibrator might work even if the radio was way off frequency-it's just a harmonic.
Did you verify that the xtal is the correct one and oscillating on the CORRECT frequency?
(You never know what the the "other guy" may have done! Assume nothing)

There isn't that much difference in the circuitry used from band to band, except the tuned circuits get switched in and out.
Also check for loose or broken connections specific to the 160 M LC's.

DL9BDM

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #4 on: October 09, 2021, 02:05:56 PM »

Just a thought: Could it be that you have the extremely rare CBM version of this transceiver? There is - instead of the 160 meter band - the maritime marine band present at the 160 meter position. The range goes from 2.2 to 2.7 MHz, if I remember correctly. The built-in AM filter allows this assumption. If this is the case, you will not be able to tune the radio to 1.8 to 2.0 MHz. However, the CBM version normally also has a third range at the scale.
« Last Edit: October 09, 2021, 02:11:07 PM by DL9BDM »
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DL9BDM

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #5 on: October 09, 2021, 02:29:20 PM »

The original 160 meter band crystal has a frequency of 7.52 MHz. If a CBM marine crystal is used, it should have 8.22 MHz. All without consulting the documentation - only from my old brain memory, without guarantee.
« Last Edit: October 09, 2021, 02:33:07 PM by DL9BDM »
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AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #6 on: October 10, 2021, 06:35:30 AM »

Thanks for the ideas. When I bought this FT-101E it did not have a 160M crystal in it. After I got the rig working, I went on ebay and bought a 160M crystal. When it arrived it looked like a OE crystal that came in a FT-101 rig. On the crystal body was stamped 7.52. However I wonder..............

Further testing indicates that this crystal MAY be way off frequency or worse. It may be way off 7.52 MHz. I can test that later today.

I get NO signals between 1.8 - 2.0 even when another rig hears a lot of 160M signals.  However when I tune the VFO down to 1.7 and lower down to 1.5, I get a lot of short wave BC signals.

I doubt that the original 7.52 crystal that I bought on ebay has aged this far off frequency.

I do not have another 160M crystal, but I do have a very stable signal generator. I plan to inject a 7.52 MHz signal from the signal generator into place of the 7.52 MHz crystal. I will let you know what I found.
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KM1H

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #7 on: October 10, 2021, 09:07:27 AM »

Many crystals using that soldered holder have failed over the decades due to a slow poisoning of the crystal by the flux vapors released during soldering. Very common with Drake crystals IME.

Those crystals can often be unsoldered and cleaned with TLC and restored to use. It just takes a good setup, patience and a steady hand.

Carl
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AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #8 on: October 10, 2021, 04:26:22 PM »

Thanks for all the info.

First of all, I bought this FT-101E at a hamfest several years ago. A guy had around 10 Yeasu FT-101 vintage rigs. I bought what I though was the best of the lot for $90. It is a late run FT-101E. It does not have 11 meters on the band switch.

When I got it home, I noticed that all 4 of the OE 10 meter crystals were missing. The 160M crystal was also missing. There was an AM filter where the CW filter went. So I assumed it was a refugee from CB, but is was clean and I got it for a song.

The reason it would not work was the 13VDC supply was showing zero volts. Both diodes in the 13V power supply were open. That was an easy fix and the rig started receiving some what.

After piddling with it for a couple of sessions, I got it working quite well on 80-15 meters. I get good reports on the air. I can "hear" a -120 dB carrier on all bands from my HP 8640B signal generator. Power out is around 100 watts on all bands except 40M where I can only get around 70 watts.

Getting to the chase.

Today a friend brought his mint FT-101E to let me compare the rigs. Opened both rigs and I cannot see any differences. His rig has all crystals for all bands.

I swapped the 160M I bought on ebay from my FT-101E into his rig. The ebay crystal worked perfectly in his rig. Then I put the 160M crystal from his rig into my FT-101E. My rig went ballistic on some unknown frequency, but not on 160M.

Since my friend told me to keep his FT-101E for a while, this is where I left things for today.

I have a decent repair bench but most old equipment. The limited nut on the wheel is me. I have a HP 141T spectrum analyzer with tracking generator and an IFR 1200 Super and an IFR 1500 with all the options. Lot of other stuff like HP counters, HP signals generators, Tek scopes, etc.

Tomorrow I plan to sweep my FT-101E on the 160M band to try to see just which frequency it is working on. It sure is not 1.8-2.0 MHz.

But then I may just leave things as is and use the FT-101E on 80-10meters and leave 160M alone. I have around 60 boat anchor rigs that I restored over the years. All work well. When I got older I started buying rigs from the 1960's through the 1980's when I was younger and when I could only drool over them. I have many rigs that will cover 160M but my inner self generally won't give up. Time will tell.

Thanks for all the replies.

Dick AD4U
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AC2EU

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #9 on: October 10, 2021, 06:55:24 PM »

Yes the sweep test should be interesting!
Also put a frequency counter on the the output of the Het oscillator.
Hopefully ,Between those two tests, you will gain the insights you need to effect a repair.

HAMHOCK75

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #10 on: October 10, 2021, 10:45:57 PM »

With that much test equipment, you should have no problem identifying the frequency of the 160M heterodyne oscillator. Just put one of your scopes on the oscillator or take a cable and terminate it in a loop to one of your spectrum analyzers. The loop is just to act as a small antenna so you can pickup the oscillator on the analyzer. I do that to tune up oscillators without touching them.

P.S. My FT101EE came with a full complement of 10M position crystals but three where for foreign CB bands. I didn't realize that until I tried to tune the low end of 10M but the pre-selector was way off but peaked just fine.That's another way to figure out where the heterodyne oscillator is actually working.
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AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #11 on: October 13, 2021, 05:09:19 AM »

I did not disappear. I am battling cancer and I get chemo 3 days in a row with 10 days off. Chemo will take all the wind out of your sails. In a few days I will feel better and will get back on the FT-101E mystery.  "Stay Tuned".

Dick AD4U
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K5WLR

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #12 on: October 13, 2021, 02:49:15 PM »

Sorry about your health issue, Dick. I pray your chemo does its work quickly and efficiently and you get back to full health soon! Looking forward to the solution to your unusual radio problem.

73!
Will Rogers
K5WLR
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AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #13 on: October 16, 2021, 06:55:05 AM »

Update - kinda. As I posted this FT-101E was a hamfest project that cost me $90. It looked clean so I bought it knowing it probably needs some work. After locating and repairing the issues, it started working quite well.

As I bought it the only band crystals were in it was 80, 40, 20, and 15. All other crystal positions were vacant. Since it had the AM filter and since the four 10 meter crystals were missing, I assumed it was used on CB.

I bought a 160M crystal (7.52 Mhz) off ebay with NO RETURN. I noticed that one of the two pins on this crystal was epoxied in place. This is the first 160M crystal I tried. It would not oscillate. I assumed someone tried to repair the crystal pin with glue.

Earlier this week I bought a complete crystal deck that was removed from a parts FT-101E. This crystal deck has ALL crystals from 160M - 10M.

I installed the four 10M crystals and they work. I installed the 10 MHz WWV crystal and it worked. I can get WWV and can received the WARC 10.10 - 10.15 band. The crystal deck even had the Yaesu CB crystal for 27.0-27.5. I installed it in the AUX position and it worked and I can listen to CB. When I installed the 160M crystal, it will not oscillate. I installed it in another FT-101E and it oscillates.

No amount of adjustment on the oscillate trimmer for 160M will make it oscillate. This is and large mica trimmer named TC26. It looks OK.

My project this weekend (if chemo allows) is to remove the screws that hold the entire oscillate board so I can carefully expose the back side of the board to see if anything is not like it should be. Then try to locate the two wires from the 160M crystal socket and trace them from the socket to the 160M trimmer and to the band switch.

Thanks for all the ideas.

Dick AD4U
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AD4U

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Re: FT-101E No 160 meter power out and very poor recieve
« Reply #14 on: October 17, 2021, 11:29:24 AM »

Mystery is solved. I removed the oscillator trimmer board or what ever it is called. Under TC26 (the 160M crystal oscillator trimmer) and under TC25 (the WWV 10 MHz crystal oscillator trimmer) are fix value caps. These fixed caps bring the oscillator circuit into a range that the trimmer can adjust the crystal into oscillation.

For what ever reason, one leg of each fix value caps under TC25 and TC26 had been lifted. Neither trimmer TC25 and TC26 alone could make the crystal oscillate.

All is well now. My hamfest junk FT-101E is now working on ALL BANDS including 160M.

I am quite sure this FT-101E was as CB queen in its past life. Why would anyone want to lift the fixed caps under the 160M trimmer cap and under the WWV trimmer cap to make the rig work better on CB.

Again thanks for all the help.

Dick AD4U

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