TS-450s display problem

[BJ radionut]

i was thinking about using a 825 watt ATX PSU, but reading about using these psus for ham radio is not recommended

JTPS-28M JETSTREAM JTPS28M 28 AMP SURGE, 25 AMP CONT POWER SUPPLY W/METERS (rlham.com)

JTPS-28 JETSTREAM JTPS28 28 AMP SURGE, 25 AMP CONT POWER SUPPLY SWITCHING (rlham.com)

MFJ-4230MV MFJ MFJ4230MV COMPACT 30A SWITCHING POWER SUPPLY,METER,ADJ 4-16V (rlham.com)

R&L Electronics Search Results Power Supplies (rlham.com)

 

[codecxbox]

The snakes head finally showed itself..
I hooked the radio to a new car battery..
Did the atu procedure, same thing warning beep..then I reset the radio with Power on and A=B..I had my DMM reading current, reads 1.32 RX..while I was selecting 10 meter band, I was hearing some chat, then it sounded garbled and the display went showing only dots and a CW code..turned it off for 5 minutes, listened again then the dots and the code and it went quiet..I noticed that when this happened, current went from 1.32 to 1.41, so theres a power draw there..looking around the net, its seems that Im getting the PLL unlock symptom..owners around the world say its the VCO2 out of spec voltage, but that small current draw is scary..dont know what to do..help!

 

[nomadradio]

Or is the computer that runs the show inside that radio running amok?

I seem to remember this radio having a lithium coin cell backing up a memory chip. When they run down, the data in the memory can be corrupted and lead to novel behavior.

Not every radio is equally susceptible to this, and I have no prior experience with that model behaving this way.

Just an intuitive fancy.

73

 

[BJ radionut]

Help! I Just Got a TS-450/690. (qsl.net)

mods.dk - Articles for Kenwood 'TS-450'

http://www.iw2nmx.it/Kenwood - Trio...Service Manual/TS-690S Instruction Manual.pdf

http://www.wz5q.net/manuals/ts450s/ts450sServiceManualPDF.zip

 

[codecxbox]

thks!!
Got 0.7v at TP3 next to the VCO2 box..its supposed to have at least 4.0..
rechecked again at all bands, same thing 0.7v..funny thing is the radio was perfectly RX at all bands 2 hours before

 

[codecxbox]

Removed the VCO2 top, adjusted TC1 to 5.64 volts, its now RX well at all bands!
Was scared a lot, theres a continous alarm beep until TC1 is within operating specs..turn very slowly! just like adjusting a 148 1st gen VCO!

 

[codecxbox]

Finally I got 10 watts CW with the autotune procedure but it didnt match the dummy load..I think I found why..the dummy load never screwed completely to the radio ant SO..so I decided to replace it..opening the bandpass board, I saw this very thin crack around the corner screw..the ground loop was open and the board was split from the ground circuit..by what I have learned upto now with the Teaberry, chassis ground IS NOT the same as electrical ground, in fact this bandpass board might be ground isolated from the chassis..well its late and Im tired..Tommorow hopefully be a great day!

 

[codecxbox]

fixed the ground issue..upto now, Im getting 10 watts at 1.5 swr at all bands without the ATU..if I turn on and use the ATU, I get the warning beep..which makes me confused..Im supposed to expect 1.1 with the dummy..does the TS 450 SWR function calibrates itself?

 

[BJ radionut]

KA7OEI's blog: Fixing the squealing auto-tuner motors in the Kenwood TS-450

TS-450S_TS-690S_broch.pdf (radiomanual.info)

Check for LEAKY Caps!!!! And do the battery mod!!!! Check leakage issues...
These couple items create a multitude of issues.

Help! I Just Got a TS-450/690. (qsl.net)

 

[codecxbox]

Following BJs forwarded articles, I believe this tuner is bad in terms of not detecting SWR..When I press THRU and Send to check SWR on a dummy load, I get 1.5 from 29 to 3.5..If I press Auto and AT TUNE, gears keep jiggling, doesnt turn fully either way..If I move the outer bottom plastic cog with my finger, it will tune to 1.1 but only on 21, 24, and 28..

 

[codecxbox]

ok, may have found possible problems..its seems the tuner coax rf lines have been pulled by the sleeve, the inner pins wouldnt insert fully to the rf sockets..I dont know if these lines are available around, highy doubt it..gonna have to risk fixing that myself..
then we got very hard to turn pots..30 year rig? yup, should expect that..Wd40 and now its really loose..Ill drop some sewing oil as soon the Wd40 dries up..
the radio operator instructions to fix the tuner has the pots resistance values different from what I got..I got 5.196K ohms fully meshed right cap..the left cap is wrong cuz it was stuck..gonna try to test the motors before installing back..

 

[codecxbox]

Hi! long time!
After troubleshooting the ATU per the online procedure...everything is good! nobody told me the atu has a limited range (3:1)!
pretty happy with the rig..thanks BJ..