wasted 13hrs on kenwood Ts940s ham radio!

so the radio has always had problems but low rx and audio level were my biggest concern.
the pll board is a problem as is cold solder joints and un known modifications to control board!

[@mixradiointernationalshortwave]

The one I have I keep working with many Hi Fi mods including a SDR interface. It is a fantastic radio. I have repaired many 940s. I have another one that is doing something similar to yours that I have not got around to fixing. You may need to recheck your the soldering to make sure no bridges occurred. Check the black sticky pads as I have removed them because they can cause conductivity across the board. The glue can can damage the lands as well. It sounds like you were close to getting it working. The FET transistor that has the drain and source reversed will only add a little more receive gain to a working 940. It will not cause of low receive.

[@hamradiohack]

I got it fixed. Its never sounded this good on rx. Wow. The pll i had to check carefully and reflow around the 3 vco that werent locked. Then i found a streched wire at a header pin that was the rx issue. Its been 2 years I've had this and its never worked this well. Lots of soldering, lots

[@mixradiointernationalshortwave]

Fantastic. To prevent power supply damage. The transistor on the heatsink to the voltage regulator board needs to be soldered directly to the wires on both sides with no connectors. Over time the connection is lost due to heat. If you do this mod be very careful making sure that the wires are correct otherwise it will blow transistors.

[@hamradiohack]

@mixradiointernational2294 the fans are in series and always on so that keeps a load on the 24v supply. Im not familiar with what you're talking about but Im aware that theres issues. I honestly dont want to deal with any more 940s

[@mixradiointernationalshortwave]

I leve mine on 24/7 With replacement computer fans. I will work on a 940 over the newer SMD stuff. @@hamradiohack

[@624radicalham]

@@hamradiohack Can you tell us here where this "stretched wire at a header pin" is? On what board. What connector? This is really gonna help people if you share information. Of course you remember which stretched wire it was. Help some brothers out man

[@tomsworkshop5856]

The battery you replaced. That almost looks like a 1.25v NiCad. If it is, 1 volt ain't that bad. Also, sometimes PLL systems won't work right if they're free-floating away from the chassis (As that acts as ground, shield, etc.)

[@Littlelewie151]

Dont give up. Seems like urs is in better shape than mine. If you get a hold of me i could walk you through fixing the pll. All you need is a volt meter and a set of alignment screwdrivers.

[@wolfhawg]

No matter what happens you learned something. Happens to me all the time. 73s

[@richardhoffman8721]

Don't feel bad, I got two ten-tec's that I have to dig into.

[@hamradiohack]

I have a corsair ii that drifts lol

[@BatGS]

Greetings: Radios and guys such ss this made me a lot of $ when I had my shop. No disrespect. Kind of the dame as many mechanic shops 2day. Most R not self skilled or knowledgeable. They rely on flow charts and Ujunk. Us old troubleshooters, engineers and techs may not B of the future but ee sure could knock out some stuff in the past. Thx 4 the share.

[@hamradiohack]

Im not cut out for fixing radios. I did go to college and study electronics and television repair. Wasnt my thing.

[@hamradiohack]

Fyi i got it fixed finally tonight. And the rx is amazing but this is silly. I have many hours into it. But its finally working how it should

[@stevepatterson2290]

some things are meant to be for parts

[@hamradiohack]

Fixed

[@leftover1955]

i got two of those ts940s that do the same thing every now then can't figure it out either

[@hamradiohack]

Soldering im sure. I found issues in the control board to be the worst.

[@GarthWheeler]

Check the vco

[@hamradiohack]

3 werent locked. Soldered the board in those areas and got it all fixed up about a hour ago. Its working great.

[@GarthWheeler]

very good@@hamradiohack

[@Darryl_Frost]

You want to get yourself some test equipment, a circuit diagram and do actual fault finding. better than a scatter shot method.

[@hamradiohack]

Its fixed. I tested the pll board and the 3 vcos were out of lock. Then i found a problem on the control board that resolved the rx issues

[@Darryl_Frost]

@@hamradiohack excellent, they are a good rig, and I love your shack. you are very well geared.

[@hamradiohack]

@Darryl_Frost i try to get the good stuff. Arizona is or was good for deals on radios and stuff because there's alot of older people who move here.

[@Darryl_Frost]

@@hamradiohack great, I love all the oldschool gear as well, I used to dream about owning a TS 940, the best I had was the TS 120 in the 80's. Aussie ham here, VK1DRL. Cheers..