Great video and a lot of useful information. I just happen to acquire a KWD TS-440/s from a ham friend's (SK) widow that has the dot issue. I had watched a lot of reviews on how to repair this issue by removing the glue. Well the radio works and transmits on 20 Meters, 17 Meters and 15 Meters fine, but 160 Meters, 80 Meters, 40 Meters, 12 Meters and 10 Meters are all dots. Well I discovered that the glue was still in VXO5 and I removed it. Still the dots remained on those bands. Then I took the bottom cover off and discovered that the PLL VCO had already had the glue removed, by whom I do not know, but they did awful work. Upon really close inspection of the PLL VCO I see that D51 diode was broke in half. I believe, looking at the service manual, that D51 is a MA858 diode. I am curious if there is a substitute diode that can be used or do I need that one? I would really like to get someone with more knowledge to work on this fine radio, it has the built in tuner and it works! I am not really good with electronics just know enough to get myself in trouble. Thanks for any advice you can give me. 73 - Juddie, WD8WV
Is there a fix for the encoder so that the there is no delay in the tuning when the main tuning knob is rotated. Right now there is a gap in the tuning by about 3/4 of an inch between up and down. Otherwise the tuning is great and doesn't miss a beat.
I suspect you have a either a loose diode board in your encoder, or a clump off debris blocking a diode. I've seen loose knob mounts screw up encoders also, but you'd know if the knob was wobbly, wouldn't you? The timing of the lead/lag pulses from the encoder is pretty fussy. I believe you'll find this an easy "mechanical" fix once you get in there. Of course, being right behind the faceplate makes getting to the encoder a less than pleasant affair. I remove every knob and pot nut to get the bezel off and hope I don't have to go in from the back. If the flank attack is required, being winter, be sure to take care of all the static discharge safety precautions when handling all those digital control boards in the front of the radio.
I have lock for about 30s then dots on all bands, reflowed the PLL board. VCO 5 goes in and out. Inductor shows 4+V during lock, and unchanging 2v during unlock. Any suggestions? Dylan KI5JQS
Wilner, This is not a complicated repair. But adjusting the bias must be done carefully. You absolutely should download the Service Manual for this radio and understand what you are doing. Remove Q2,3 and unsolder from FINAL board. Locate VR1 and turn fully clockwise to minimize bias. (optionally: You can confirm minimum bias at this time by applying power and keying radio in SSB mode, NO MIC gain!, and checking for 0 volts at the base of Q2,3. ) Replace Q2,3 and solder to board. Adjusting bias: As per manual, page 94. You’ll need to insert an ammeter (about 1 amp range) in wire 14S leading to L9 on side of board. See board layout page 78. Key radio and adjust VR1 to increase driver bias current 200mA. Reconnect 14S directly. Test for RF output and reassemble radio. No further adjustments SHOULD be required. To see a similar, detailed repair on a Yaesu watch this video: th-cam.com/video/_x2FSUkvUPg/w-d-xo.html Good luck.
Great video and a lot of useful information. I just happen to acquire a KWD TS-440/s from a ham friend's (SK) widow that has the dot issue. I had watched a lot of reviews on how to repair this issue by removing the glue. Well the radio works and transmits on 20 Meters, 17 Meters and 15 Meters fine, but 160 Meters, 80 Meters, 40 Meters, 12 Meters and 10 Meters are all dots. Well I discovered that the glue was still in VXO5 and I removed it. Still the dots remained on those bands. Then I took the bottom cover off and discovered that the PLL VCO had already had the glue removed, by whom I do not know, but they did awful work. Upon really close inspection of the PLL VCO I see that D51 diode was broke in half. I believe, looking at the service manual, that D51 is a MA858 diode. I am curious if there is a substitute diode that can be used or do I need that one? I would really like to get someone with more knowledge to work on this fine radio, it has the built in tuner and it works! I am not really good with electronics just know enough to get myself in trouble. Thanks for any advice you can give me. 73 - Juddie, WD8WV
I did NOT learn a thing..I need to see WHERE in the radio you made the adjustments so I can do mine.
Is there a fix for the encoder so that the there is no delay in the tuning when the main tuning knob is rotated. Right now there is a gap in the tuning by about 3/4 of an inch between up and down. Otherwise the tuning is great and doesn't miss a beat.
I suspect you have a either a loose diode board in your encoder, or a clump off debris blocking a diode. I've seen loose knob mounts screw up encoders also, but you'd know if the knob was wobbly, wouldn't you? The timing of the lead/lag pulses from the encoder is pretty fussy. I believe you'll find this an easy "mechanical" fix once you get in there. Of course, being right behind the faceplate makes getting to the encoder a less than pleasant affair. I remove every knob and pot nut to get the bezel off and hope I don't have to go in from the back. If the flank attack is required, being winter, be sure to take care of all the static discharge safety precautions when handling all those digital control boards in the front of the radio.
I have lock for about 30s then dots on all bands, reflowed the PLL board. VCO 5 goes in and out. Inductor shows 4+V during lock, and unchanging 2v during unlock. Any suggestions?
Dylan KI5JQS
I have a few ideas. Can you send me an email at incidentalinformation@gmail.com and we can discuss further? Thanks
@@i-squared thank you for the assistance. The email I sent bounced, I will try again.
Aidé moi la remplacer .C2509 drivers pour la répare ts440s
Wilner,
This is not a complicated repair. But adjusting the bias must be done carefully.
You absolutely should download the Service Manual for this radio and understand what you are doing.
Remove Q2,3 and unsolder from FINAL board.
Locate VR1 and turn fully clockwise to minimize bias. (optionally: You can confirm minimum bias at this time by applying power and keying radio in SSB mode, NO MIC gain!, and checking for 0 volts at the base of Q2,3. )
Replace Q2,3 and solder to board.
Adjusting bias: As per manual, page 94. You’ll need to insert an ammeter (about 1 amp range) in wire 14S leading to L9 on side of board. See board layout page 78.
Key radio and adjust VR1 to increase driver bias current 200mA.
Reconnect 14S directly. Test for RF output and reassemble radio.
No further adjustments SHOULD be required.
To see a similar, detailed repair on a Yaesu watch this video: th-cam.com/video/_x2FSUkvUPg/w-d-xo.html
Good luck.