Kenwood TS-830 Wont Tune

Discussion in '"Boat Anchor" & Classic Equipment' started by KM6CTP, Jun 14, 2016.

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  1. KM6CTP

    KM6CTP Ham Member QRZ Page

    Greetings everyone-

    I just purchased a Kenwood TS-830. I'm a new HAM so I also purchased an OCF dipole 40 - 10, the matching Kenwood AT230 tuner, and a dummy load (the seller threw in a MC-50 microphone for $30). The radio arrived first so I hooked it up to my Kenwood R-2000's dipole antenna and had a great time listening with the rig, waiting for my antenna and other parts to get here before I can try to transmit. So today everything came and I got my new antenna up, and the AT-230 and dummy load all setup.

    First thing I notice with the new antenna is far better reception and my S meter is now working and registering, where it wasn't before on my old shortwave receive antenna. I'm getting all excited and go through the tune up procedure for transmit. I set to "Tune", "ALC", "Load" all the way counter clockwise, "Plate" and "Drive" at 12 oclock. Also "MIC" and "CAR" at 12 oclock. I'm very careful and never stay on send for more than 2 or 3 seconds. So I hit SEND to adjust the Drive for maximum out, and the needle barely moves, I swing the Drive knob in both directions and the needle doesn't budge. I also try the CAR adjustment and there is still no movement on the needle at all. I check the plate current per the Kenwood manual and its at 100mA, not 60mA as it should be. So I bias this down to 60mA per the instructions and try to tune again and the same thing happens.

    The AT-230 tuner shows my SWR at 1.5 on 40 meters so I know I'm close (but at low power). I haven't tuned the antenna yet as Kenwood instructions tell me to tune for transmit first.

    The Drive knob does affect receive volume and when you pan the Drive knob the volume will climb and fade. I open the unit up and nothing obvious jumps out at me. The 2 main tubes are both softly glowing amber on top and both look identical (don't see one hotter than the other) The smaller tube was sitting a bit at an angle so I checked the pins and reseated in its socket flush. It was wrapped in a black cover of sorts so I didn't see if it was glowing or not (I wish I would have now).

    I also tried to tune by removing the AT-230 tuner completely (in case it might be bad) and tune with the dipole antenna and get the same results.

    Anyway, I'm not sure what to do now. Should I just continue with tune up procedure when the Drive knob does nothing? Any help would be greatly appreciated.

    Steve Murphy
    Chico, CA
  2. HAMHOCK75

    HAMHOCK75 QRZ Member

    If I recall correctly, the TS830's have a SG switch on the back for turning off the screen grid voltage so you can neutralize the final. Might want to see it is in the right position.
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    If the needle does not move with the Carrier control all the way up then the driver is not working.

    Dirty band switch or bad driver would be suspect. Did you try other bands ?

    Have Fun.
  4. KM6CTP

    KM6CTP Ham Member QRZ Page

    1) SG switch is set to ON which the manual says is the normal operation position (slide to off to neutralize).

    2) I tried on all bands also as I have heard about low output only on certain frequencies but everywhere I go its the same.

    Thank you for your help guys, I really appreciate it. I'll see about that band switch right now. Not sure how to check for driver circuit, but it looks like I need to download the service manual. I thought one needs an oscilloscope to neutralize finals as well. Could this be from old tuners?

  5. KE4OH

    KE4OH Ham Member QRZ Page

    Correct me if I'm wrong but, isn't the first tune-up step to tune the Drive control for peak with the meter set to ALC and the function set to Tune? If no/low reading, advance the Carrier control a bit and try again?

    Then next step is set meter to RF Out, function to CW, hit Send (and close your CW key, if you have one plugged in) and adjust Tune and Load for maximum output.

    Last step, set meter to IP (Plate current) and adjust Carrier control to 220ma or less.

    If you are trying to tune for maximum output with the function set to "Tune", you will disappointed.
  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    Yes you should get the manual.

    Do you have a dummy load to test with ?

    It is Murphy's law that is working with you.

    Good Luck.
  7. KC8VWM

    KC8VWM Moderator Volunteer Moderator QRZ Page

    Yup get the manual out and go through each individual procedure, step by step. Complete each step as if you are getting ready to launch a rocket.

    If something is not working along the way, abort the mission then report back here to Qrz mission control for further instructions.
    VK4JK and KA9JLM like this.
  8. W5RKL

    W5RKL Ham Member QRZ Page

    The TS-830 SG switches does not turn the 6146 screen voltage OFF! This is a belief among a number of hams which is not true.

    The TS-830 SG Switch controls the Rectifier Unit's "RL1" relay. In the "ON" Position relay RL1 on the Rectifier Unit is not energized. This allows the normal "Positive 210A" supply voltage to be applied through relay RL1 to the MODE switch, to the Final Unit's "SG" terminal and ultimately to pin "3" of the 6146 final tubes. Placing the SG switch in the "OFF" position, energizes relay RL1 on the Rectifier Unit, changing the source of the 6146 screen voltage to the "-C bias supply" providing an approximate "negative" DC voltage of 101VDC that flows through the MODE switch, to the SG terminal on the Final Unit and ultimately to pin "3" on the 6146 tube sockets.

    The above can easily be seen by viewing the TS-830 schematic.

    The same basic circuit operation occurs in the TS-520, TS-530, and TS-820 Rectifier Units but the Rectifier Unit does not have a relay. The positive and negative DC voltage is routed through the SG switch verses being routed through a relay. See the individual KW hybrid schematics for details.

    If the ALC meter does not rise above zero in TUNE mode when adjusting the DRIVE control with the CAR control set to 12 o'clock in transmit, then check resistors R15 and R16, 1/2 watt each, on the Rectifier Unit, they may have significantly changed values. R15 and R16 form a resistor voltage divider lowering the 6146 screen voltage in TUNE mode.

    I have the TS-830 operator and service manuals on my website

    When the page comes up scroll down to the KENWOOD listing and click on the 830 user and service manual links, one at a time. I also have a high resolution schematic for the TS-830 on that same page. Download it as well.

    You should never attempt to service your TS-830 without the service manual, basic test equipment, and the necessary troubleshooting and repair skills to locate and repair problems. If you troubleshooting, repair skills and electronic knowledge is significantly lacking then I recommend you find a local ham who has these skills and test equipment to help you locate the problem in your TS-830.

    Mike W5RKL
  9. KM6CTP

    KM6CTP Ham Member QRZ Page

    Yes, you are correct and this is exactly what I did if you read the second paragraph of my initial post. I apologize if I explained it poorly (I was up all night trying to figure this out!) I listed everything you said, I set to tune, ALC, started with Load all the way counter clockwise and Plate and Drive were at 12 Oclock before I started. I hit Send and the Drive needle barely moved at all up the meter (to 3 on the S meter). Moving Drive or CAR doesn't have any impact on the needle at all. The needle doesn't move.

    I tried Kenwood's instructions on this procedure (which actually differ from many posted on You Tube and in this forum) and those listed here as well. Same thing. I've tried it with only the dummy load into the radio, with only my new dipole antenna, and with the AT-230 antenna tuner. Same effect. I'm willing to try voodoo magic and sacrifice chickens if it would work. (if only it were that easy!!!)

    When I stated I was tuning for maximum "output", I'm a rookie and that wasn't correct. I was tuning for maximum deflection on the needle in low power (Tune). This is the very first step in the process. I haven't had a chance to go to CW mode yet and adjust for maximum output of transmission. Sorry for that confusion.

    As far as experience with a electronics; I'm respectful of high voltages and have scratch built guitar amps and have kept my 40 year old Fender Super running and happy for years. I must say the guts of this radio are far more complex than any guitar amp I've ever worked on, but I can take this section by section. My first impression was positive when I opener the case and saw I had room to work. Its tight in some spots (as Murphy's Law dictates these will be the areas I'll probably have to fix) but all in all this is very doable.

    Thanks you all for your help. I really need it.

  10. KM6CTP

    KM6CTP Ham Member QRZ Page


    Many thanks. I've downloaded the service manual and schematic. Will locate those resistors and check values. Many, many thanks.


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