Want To Buy: Non-working Icom AT-120/AT-130/AT-140 Tuner

[_Claus_]

Do you have one of these tuners that is broken? Instead of throwing it into the trash I might be able to give you a couple bugs for it. I'm only a electronic hobbyist and a beginner at that who successfully repaired an AT-130 after spending way to much time tracking down the issue. Nonetheless I got hooked on trying to repair electronics and would like to try my luck on another antenna tuner. So don't expect three digits $$$, I won't be able to make you rich, sorry.

Could I repair yours? Maybe, but the risk is to high that I break the tuner more. I also only have sporadic time to work on it. That's why it's not a good idea for me to repair the tuners for others - I'm not a professional. Instead I'd like to buy the tuner outright.

Let me know if you have one of these tuners.

Thanks, Claus (amateur radio operator K0TET)

[rdkinard]

Originally Posted by _Claus_

Do you have one of these tuners that is broken? Instead of throwing it into the trash I might be able to give you a couple bugs for it. I'm only a electronic hobbyist and a beginner at that who successfully repaired an AT-130 after spending way to much time tracking down the issue. Nonetheless I got hooked on trying to repair electronics and would like to try my luck on another antenna tuner. So don't expect three digits $$$, I won't be able to make you rich, sorry.

Could I repair yours? Maybe, but the risk is to high that I break the tuner more. I also only have sporadic time to work on it. That's why it's not a good idea for me to repair the tuners for others - I'm not a professional. Instead I'd like to buy the tuner outright.

Let me know if you have one of these tuners.

Thanks, Claus (amateur radio operator K0TET)

Claus,
How can you tell if an ICOM AT-130 is “broken”?
The SWR I’m measuring, across the marine spectrum, pegs the needle to the right.
Substituting a dummy load in place of the AT-130 shows an SWR of 1.1.
Captain Rich

[_Claus_]

Originally Posted by rdkinard

Claus,
How can you tell if an ICOM AT-130 is “broken”?
The SWR I’m measuring, across the marine spectrum, pegs the needle to the right.
Substituting a dummy load in place of the AT-130 shows an SWR of 1.1.
Captain Rich

Hi Rich,


It's broken if it doesn't work.

I'm not sure what transceiver you're using. My IC-7300 will tell me if the tuning worked or not.


How are you measuring the SWR? If you're just hooking the antenna analyzer up to the AT-130 then it won't be tuned. You'd need to power the AT-130 and initiate the tuning sequence with RF applied. Easiest way to do that is to use an Icom transceiver.

At this point I guess you could disconnect the antenna cable only (leaving the control cable hooked to your still turned on transceiver). Then the SWR should measure OK with an antenna analyzer.


I bet the AT-130 wasn't powered and you just measured the antenna's and dummy load's SWR.


BTW, there are wire length that a tuner might have a hard time to tune the specific frequency. So avoid half wave length (and multiples) of the frequencies that you want to use.



Claus (AE0S)

[_Claus_]

Rich,



If you are already past that step, i.e. know it doesn't work. Then I would start trouble shooting by checking if the proper voltages / signals are sent over the control cable. Your manual describes these, check the terminal voltages and the "Start voltage [STAR]" and "Key voltage [KEY]" signals which are time based.


Good luck,

Claus

[rdkinard]

Hi Claus,
The AT-130 is connected to an M700-Pro on the input and a backstay antenna on the output.
I can connect to Sailmail stations from Trinidad to Nova Scotia to Corpus Cristi from SouthWest Florida.
When I put a Radio Shack HF SWR meter between the M700-Pro and AT-130, and transmit AM, after I first press TUNE, the SWR pegs full-scale. Repeating that with a dummy load vs the AT-130, the SWR needle barely moves.
I’m not sure if the Auto Tuner is actually working.
Captain Rich

[_Claus_]

Rich,
Checkout the manual for the IC-M700PRO.
IC-M700PRO SSB Radio Telephone - Features - Icom America


Make sure the correct connected antenna tuner is specified in the settings (page 11).

If you just got that transceiver from someone used you might want to double check that the internal tuner switch has been changed (see page 19)



When tuning if it's quiet and you're close by to the AT-130 you should hear the relays clicking while the tuner tries to figure out the best inductor & capacitor combination to tune the wire.

During that process the TUNE indicator on the LCD should be flashing. I'm not sure about the IC-M700PRO but on my IC-7300 the TUNE indicator goes off if the tuner cannot tune. I would assume it's the same for your transceiver. Something to check as well.


So:
- check that TUNE indicator is flashing for 1 or 2 seconds while you press the tune button.
- listen if you hear the relays on the AT-130 clicking

- check if the TUNE indicator is still on after pushing the tune button


Claus

[rdkinard]

Will do. I’ll let you know how it works out.
Thanks!