开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. Yaesu-FT-101
  2. Topics

FT-101 deaf above 40m

 

Hi all, new to the group. I’m about to receive a poorly 101 (original) tomorrow which I have been advised only works on 80/40m. It’s deaf on anything above those bands. Does it sound like a dirty band switch?? Or alignment more likely the issue? I’ll know more when I receive it, but just wanted a bit of a head start incase there are obvious known faults that cause this issue with this radio.?


Many thanks

?Carl M0CLS.?
 

Well I’ve received the 101 today. The first job I did was to spray all the crackly pots including the band wafer. I’ve got 15m working so far. 20m is way way off frequency. I hear FT8 signals around 14.400. More work needed
 

It may be advisable to change the electrolytic capacitors. This can fix a lot of issues without having to realign. You have cleaned the band switch which is another common problem. Don't worry too much on the two big capacitors in the power supply but you can buy a kit of the smaller caps. It can vary between versions with the kits so you may have to get a few extra caps not included with the kit.
Hope that helps. 73 de Rob ZL3RS?


On Fri, 14 Apr 2023 at 2:03, Carl
<m0clscarl@...> wrote:
Well I’ve received the 101 today. The first job I did was to spray all the crackly pots including the band wafer. I’ve got 15m working so far. 20m is way way off frequency. I hear FT8 signals around 14.400. More work needed

 

Another thing is to take photos of each of the boards before you start so you have a reference plus only change one at a time making sure of the polarity.?
That way you should not go wrong.? All the best... Rob?


On Fri, 14 Apr 2023 at 7:31, Rob Stokes
<rjstokesonline@...> wrote:
It may be advisable to change the electrolytic capacitors. This can fix a lot of issues without having to realign. You have cleaned the band switch which is another common problem. Don't worry too much on the two big capacitors in the power supply but you can buy a kit of the smaller caps. It can vary between versions with the kits so you may have to get a few extra caps not included with the kit.
Hope that helps. 73 de Rob ZL3RS?


On Fri, 14 Apr 2023 at 2:03, Carl
<m0clscarl@...> wrote:
Well I’ve received the 101 today. The first job I did was to spray all the crackly pots including the band wafer. I’ve got 15m working so far. 20m is way way off frequency. I hear FT8 signals around 14.400. More work needed

 

Thanks Rob I’ll do that.

I’ve managed to get every band working now other than 20 meters which will not align at all. In fact I’m hearing LSB signals around 14:400 and FT8 at 14:450ish! Could it be the crystal???
 

Well I’m still no further with this. Every band working but for 20 meters. When transmitting a carrier at 14.250 on the 101s display my SDR showed the signal at 9.320. So I presume that’s where it’s receiving. Also when I transmitted a USB signal it is coming out as LSB on the SDR. So somethings really wrong on 20. Any ideas what I should be checking??


Thanks.?
 

开云体育

Carl,

?

The 20m oscillator xtal X3 (20.02 MHZ) on the heterodyne crystal oscillator board may be bad.

?

?

?

Regards,

?

Tony

?

VA7TF? VE7ACF

?

From: Carl
Sent: April 15, 2023 6:50 AM
To: [email protected]
Subject: Re: [Yaesu-FT-101] FT-101 deaf above 40m

?

Well I’m still no further with this. Every band working but for 20 meters. When transmitting a carrier at 14.250 on the 101s display my SDR showed the signal at 9.320. So I presume that’s where it’s receiving. Also when I transmitted a USB signal it is coming out as LSB on the SDR. So somethings really wrong on 20. Any ideas what I should be checking??


Thanks.?

?

01DE600DC78843AA95E0EECC757928B9.png

 

Thanks Tony, this is what I suspected. I’ve ordered one off eBay so fingers crossed it’s a working one and it solves the problem. TC18 also shattered when I was attempting to tune the crystal (symptoms were already present) so I’ve ordered a used board to swap that out. Does anyone know of a good new replacement? I see plenty of ceramic Chinese trimmers but all of them seem to be two leg instead of 3. Or does that not matter???
 

开云体育

Carl,

?

With the 3 leg trimmers, 2 legs are the same connection, the other is the variable connection.

?

Was the 20m receiving before you tried adjusting T18?

?

?

?

Regards,

?

TF

?

From: Carl
Sent: April 15, 2023 10:41 AM
To: [email protected]
Subject: Re: [Yaesu-FT-101] FT-101 deaf above 40m

?

Thanks Tony, this is what I suspected. I’ve ordered one off eBay so fingers crossed it’s a working one and it solves the problem. TC18 also shattered when I was attempting to tune the crystal (symptoms were already present) so I’ve ordered a used board to swap that out. Does anyone know of a good new replacement? I see plenty of ceramic Chinese trimmers but all of them seem to be two leg instead of 3. Or does that not matter???

?

4FC1F7E3A8E042ACAFA948CF6FF67401.png

 

Ah yes noticed on the schematic, thanks.?


No 20 meters wasn’t working before. I tried adjusting TC18 during the alignment and first found it did nothing, then broke completely.?
 

开云体育

Hi Carl,

As you've already discovered, the caps have just the two connections.? The right side is the rotor connected to ground.? The small lead on the left connects the stator to the xtal.? Three of mine failed with the solder bridge connecting the rotor screw to the rotor plate breaking loose, rendering them useless.? I was not successful in reheating the solder.

I'm presently experimenting with using the inexpensive plastic trimmers to replace the ceramic ones.? They are available on Amazon, Ebay, etc.? Each one needs to be verified with a capacitor tester.?

Do you have an RF probe connected to the RF board test port so you can monitor the oscillator signal level?

Good luck and keep us updated on your progress!

Richard kn7saf




On 4/15/2023 10:41 AM, Carl wrote:

Thanks Tony, this is what I suspected. I’ve ordered one off eBay so fingers crossed it’s a working one and it solves the problem. TC18 also shattered when I was attempting to tune the crystal (symptoms were already present) so I’ve ordered a used board to swap that out. Does anyone know of a good new replacement? I see plenty of ceramic Chinese trimmers but all of them seem to be two leg instead of 3. Or does that not matter???
 

Richard thanks.?

No I don’t have any test equipment other than other radios receivers, DMM (not much use here) etc. I used a nanovna as a signal generator for the other bands alignment and that went well, I was able to peak the signal from that. I understand not having the correct test equipment isn’t ideal, but the way I’ve aligned it so far has improved the other bands sensitivity. Would building an rf probe for my DMM be useful??


Thanks.?
 

开云体育



On 4/16/2023 12:36 AM, Carl wrote:

Richard thanks.?

No I don’t have any test equipment other than other radios receivers, DMM (not much use here) etc. I used a nanovna as a signal generator for the other bands alignment and that went well, I was able to peak the signal from that. I understand not having the correct test equipment isn’t ideal, but the way I’ve aligned it so far has improved the other bands sensitivity.


Would building an rf probe for my DMM be useful?


Yes, by all means and there are plenty of YouTube videos on how to do that.? You can also use the probe with an analog voltmeter if that's all you have.? The manual wants you to shoot for 300mv injection at the test point on the RF board for each band when you adjust the oscillator trimmers.? I have noticed that the receiver sensitivity doesn't seem to drop off until the injection drops below 200mv.? At least with the extra receiver, you can determine that each xtal is operating at its design frequency and detect a dead one.? Mine has been on the bench for weeks and I work on it as time permits, loving the learning experience!

Richard


Thanks.?
Nigel jones 2E0NJT
 

Richard

check out the photos section for “ rf tester for dmm” i have uploaded an adaptor you could build to give you the test results you need.

nigel
Nigel jones 2E0NJT
 

To all

The moderator Roger has found a better quality copy of the article for the dmm connected rf voltmeter and has posted it in the files section, i have therefore removed the un needed photos of the article to save some memory in the forum.

nigel?
 

Update - I’ve replaced the 20m crystal and it’s now working well!?

I have a question though. I’ve been aligning the clarifier and the tx/rx with the Zero adjust. I noticed all the guides online show the voltage around 3.5-3.8v at the clarifier input. Mine is 1.6v?? Could there be an issue on the rectifier board?? I managed to align tx and rx but it was very tight with the zero adjustment almost fully clockwise!?

1 - 16 of 16