Kenwood TS-940 HF Transceiver, should you buy one?
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- čas přidán 9. 09. 2024
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all4radios.com The Kenwood TS-940 Transceiver is now a true classic radio for ham radio enthusiasts. It's like owning an old car, you really have to love repairing it if you want to own one.
In a good condition expect to pay around $500 for it. There are always spares available on Ebay but watch out who the seller is.
One known board to fail over time is the PLL board. It often drifts and the display only shows dots. It comes back to life if you spin the VFO. If that happens it's time to re-align the PLL board. Buying one on Ebay does not solve the problem, because it is still necessary to calibrate the new board.
Stay clear of a radio that comes from a heavy smoker, nicotine is sticky and can cause a lot of problems.
Keep in mind that this radio is now 40 years old and will require some TLC soon.
Operating it is fun and they are well worth the cost of ownership.
The TS-940 is a legend, one of the best Ham transceivers ever built. I bought one in 1987 and used it for about 15 years. I spent over 30 years earning a living doing component level repair on scientific and research electronics. Since I retired in 2012, I've repaired several dozen 940s. What I usually do is offer a set price for a total restoration of the functionality of a radio. So far, I haven't failed. 73
How much do you charge for a total restoration?
@@rockyross7334
You'd think with a plug like that you would get a response. So what do you think about his comment?
The TS 940 is really a classic radio which is using a big components and it is easy to repair, the receiver is hot and very effective to null noise from the band. I like most is the authentic sounding both in receive and transmit which is very hard to find in the modern radio. Mine has never had any problem after changing the electrolytic capacitors
I have a TS-940S with a no tune antenna tuner. I changed the tuner unit from another TS-940S and same thing no work. But other than that I used the rig for about 4 years and gave it a rest. Nice radio but the ham that I bought it from added a roofing filter and I took it out back to stock condition. Thanks for the video
I have owned my TS 940 sat for about 15 years or so and it is still working perfectly. I will continue to keep it in my shack and take it for a spin every once in a while (Sunday drive) hihi. Its no longer my main rig but will most likely hang on to it well into the future. I also have the sm220 scope that is connected and it still works as well. My next purchase is going to be a TS890 if I can ever afford it! 73...
It all depends on your technical skill level. The 940 is an older radio and it has a set of known problems. If you have the skills, time, and patience you can grind through the problems. I bought mine from a local ham and although it worked when he fired it up it failed after I got it home. I went through the dots problem and the rig settled into a mode where it would go berserk after a period of time. Turning it off for a while and resetting the rig with the A=B switch would buy some time. I began to concentrate my efforts on the Digital A board, resoldering every joint on the bottom. I also resoldered every joint on the Digital B and C boards. Today, on a hunch, I resoldered every pin on the CPU from the topside of the board. It ran for the longest time yet, two hours with one hiccup. The dreaded eight hour test will be next weekend. These rigs are known to have been assembled with rotten solder joints and you have to go over every joint, every via, on BOTH SIDES of the digital boards. Unless you have good power supplies, PLL boards, and digital boards intelligent troubleshooting is impossible.
Is this true of 440s as well, every solder joint needs recooked?
@@gonebamboo4116 , yes indeed. I finally gave up on the 940 and got rid of it. My TS-2000 began giving me the "UL" bit and after doing the PLL alignment failed to fix it it was sold this summer. I now have a Yaesu FTdx1200 and a FT-990 to keep the two TS-430s company.
Like you said, TS940 is a great classic rig but with some weaknesses like the PLL due to this wax they put in there! I had to clean up mine when it displayed the famous dotted frequency. Other than that, it performs like a charm. I also reversed two FET transitors that were mounted the wrong way by Kenwood, see this by googling on the internet (tip provided by a PY ham). I bought mine in California as a second hand rig when doing a world tour 25 years ago, so an old friend I would never sell! Michel, LX1KM 73s Thanks for this video!
The story of TS-940 FETs reversal has been one of the biggest oax in the story of this transceiver. FET used in 940 are simmetrical, so reversing Drain with Source does not produce any change.
@@MarioIZ0IRH
Interesting, where do you get that info?
i hove one i ober 15 years good radio 73 from texas usa
The 940 is a fine radio. I've had one for about 15 years or better and never had any problems with it... until one day the CW portion decided to stop working. Zero receive on CW. Still works great on all other modes. I just now decided to tear it apart and see what's going on, and interestingly enough, no Carrier 4 signal in CW mode. I suppose that could do it! Going to start looking deeper and seeing what has failed.
Hmm, I finally got that 751 you recommended a long time ago. I will have to consider this
I have an 8 million serial 940s whose 17 IF transformers lost capacity and I had to add capacitors behind all the transformers with 27pf to 220pf and success to make it work again. But I still can't fix the power drive TX signal which slowly continues to decrease to 50% since radio turning it on, which problem will disappear if I blow fresh air around on the 3rd TX mixer in the RF unit, has anyone experienced this? Please help me because I'm really almost giving up
A friend dropped one off for repair. The issue: Not sure which cooked first, Q101 & Q102 or the AVR board. Either way, when they fail, 40+ volts is sent to connector FB which feeds the final board. The surge of voltage will cook D1, a 36 volt zener diode; D5, a 19 volt zener diode; Q2 and Q3, MRF485 driver transistors.
The owner doesn't want to sink any money in the rig for repair; he will sell it as is.
My suggestion, replace the electrolytic capacitors on the AVR board and possibly replace Q1, Q2 and Q6. Also consider replacing Q101 and Q102.
Why? Because the MRF485 transistors are hard to find, no longer produced and NOS replacements fetch a premium price $40 each here in the US.
replace the power supply complete for a switching upgrade
@@lampa2001
That is what I see most owners doing now.
Hola como.puedo habilitar para transmitir en 6993?
I see most of these old radio being used on the free band 26.965 to 27.991 usb as they come up cheaper than buying a euro boxer
I have one with the PLL issue.
Seems the BPF in pll needs alignment.
Should be simple fix... The Service Manual is a nightmare!..
Runs for a bit , then starts warbling!..
I have all the test gear, but am stuck.
Hello! I just inherited my grandfathers entire HAM station, including this exact transceiver. It’s been in storage since 1994. I have no idea where to start. I would love to learn how to set it back up! Any advice is welcome.
I have the kenwood ts-940 it drops one kilohertz every time you key the transmitter... what could the problem be ....
I have one of these and it's a problem child. Been looking for a used PLL board, with none to be found.
How are the batteries? My 940 will need replacing soon.
Hi, have one of the late serial numbered -940SAT. It works ok but the the memory push buttons are not working. Should I open the front plate, remove the PCB to see the contact surfaces of the buttons ?
Hi, are You repair memory buttons? Because I have this same problem in my 940. And I don't know what to do. 73!
I have two of them but not working lol. And also two TS-930s also not working
we can talk
How much are these transceivers nowadays? Have a barely use one to sell.
Sold it yet?
about $500
Nice to hear from you again, says you now have 666 subscribers, is this saying something? All the best from Carl.
I already subbed?😂Another great video! 73 de VK2AOE