Kenwood TS-940 Upgrades

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Kenwood TS-940 Upgrades

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4 жыл бұрын

This is just a quick overview of some modifications and issues with another old Kenwood HF Radio. New Drivers, LEDs and an S Meter issue.

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@willieevans718 3 жыл бұрын

i have had my 940 for many years now and I always loved it but it got the kenwood dots and I have it packed away now.i cant find anybody around me that works on them but they are great radios,a nice receiver they have

@dri50 2 жыл бұрын

There are several causes for this issue. The Kenwood 940 Group has a wrie-up in the files section on how to troubleshoot this problem.

@michaelofmarble2094 3 жыл бұрын

Looking to get my 940 back on the air. I had a huge hemlock tree hit by lighting, after it exploded, it knocked over 3 other trees with my 80m and 40m dipole in them. Thank you for your video.

@dsagun727 2 жыл бұрын

Great info, I had two 940s and they worked great.

@Robert-hr6sh Жыл бұрын

Thank you for the upgrades!! 73's

@ojjenkins7110 3 жыл бұрын

Have you seen Buddy's latest video? He pulled the EPROM and cleaned all the pins on it and the contacts where it plugs into with D5. A friend of mine D5'd every plug with a tooth pick or something like that, all 200 or so of them, to get his to play.

@timtimeprojects3576 3 жыл бұрын

Yes I did see Buddy's video. I also seem to remember Kenwood having an issue where they recommend removing the socket and soldering the IC in place. Can't remember which radio it was for. Bad connectors and weak solder joints caused all the issues on mine. Thanks for watching.

@dri50 3 жыл бұрын

I picked up one of these a couple of months ago, not working. Based on the serial number and the date code on the chips (1989), mine is probably from 1990. I think the first year production was 1985. Kenwood issued 13 service bulletins on this model. Some of the bulletins do require hacking the pc brds. Does anyone know the original MSRP? I thought I read it was around $2600.

@timtimeprojects3576 3 жыл бұрын

EHam says about $2500.

@marcozbo Жыл бұрын

Hi, nice video. The real issue is in the AGC circuit and I have a similar problem. I replaced/checked all electrolytics in the AGC chain and they were fine. I don't know if it's some faulty component or if the radio is like this from the factory... did you discover anything in the meantime?

@timtimeprojects3576 Жыл бұрын

Somebody did some mods to this at one point and I feel like some solder joints may still be throwing gremlins into the machine. So , I just keep plugging away when I get time. It is due for a re-capping as well.

@marcozbo Жыл бұрын

@@timtimeprojects3576 Finally I fixed the issues with mine. The problem was that a few IF and RF board coils were out of tune. Basically I tuned exactly the AGC voltage at 3.2V, then VR2 to center and L44 to 46 on the RF board for maximum signal, then, on the IF board, L7 to 15, L17 and from L23 to 25. At this point it was very easy to setup the S-meter to be sensitive down to S2 signals (I mean real S2, -115 dBm). The service manual has a mistake (more than one 😀) as it wrongly suggests to set VR1 (RF board) fully CCW, and instead it should be set to obtain the right voltages as per schematic. Now my S-meter is almost perfect as my calibrated SDR and I haven't any more those horrible AGC overshoots with narrow CW bandwidth and fast AGC. Hope it helps! If you need any more info that I'm capable of, feel free to ask. 73, IS0KYB

@marcuscheko3264 6 ай бұрын

@marcozbo thanks for info ...currently working on ts-940s, waiting on pwr sply and PA board for replacement. I'll make a note of your findings in my service manuel . I should have a brand new running rig after all the upgrades and look forward in other suggestions 73 , de N5OMV