Modifications for the Kenwood TS-830

Modification to TS-830S, TS-530S

Subscriber's comments on qro modification to TS-830S, TS-530S and TS-530SP

I would like to pass on the problem I hace encountered in connection with the QRO modification to the Kenwood radios TS830S, TS-530S and the TS-530SP.

The problem occurs after many hours of long winded QSO's. It seems that with the increase in the screen voltage from 210 to 300 volts, R37 on the RF unit (#X44-1360-00) heats up tremendously and will change it's value so greatly that even the receive either suffers or goes out totally. R37 originally is Metalfilm resistor at 3.3K ohms and is 1/2 watt.

I have changed mine to a Metalfilm as original same value but have used a one watt resistor. The brand I was abble to get was RCA and I suppose there are better on the market. This is a 2% tolerance. Three units that I know of have had this problem that I took care of in this area alone. Two units were TS-830S and one a TS-530SP. Just thought I would pass that information along for what it is worth. (Thanks, Frank J. Lukas, Jr., 5301 Main Ave., North Ridgeville, OH 44039)
TS-830S Frequency Shift

Some users may report an intermittent shift in the display and operating frequency. This may typically be a 1 to 4 kHz random shift. Cause will be a loose grounding screw on the AF/AVR unit heat sink.

On the AF/AVR unit X49-1140-00, there are three self-tapping screws holding the aluminum heat sink to the PCB. These also supply the ground connection to that section of the board. Between the heat shink and PCB foil, add a toothe-lockwasher N17-1030-41 at eht two self-tapping screws on the side of the heatsink that has the two transistors attached. (The remaining screw already has a lock washer.) When replacing the board to the chassis, add a solder lug E23-0420-05 to the heat sink mounting screw as shown, and tighten all screws for this board. Solder an insulated lead between the TPG (Test Point Ground) wrap post adjacent to C81, and the added solder lug.

  1. Remove the top cover (8 screws) and unplug the speaker.
  2. Remove the bottom cover (8 screws).
  3. Remove 5 screws holding the AF/AVR unit and swing the board over. Leads do not have to be unplugged.
  4. Add two tooth-lock washer as shown.
  5. Replace the circuit board and heat sink to the chassis, adding the solder lug as shown.
  6. Solder a jumper between the TPG wrap post and the added solder lug.
  7. Replace the top and bottom covers.
Installation time for this procedure is 1/2 hour or less.
Amtor modification

  1. Remove C500 (4.7uF) on the signal board (located top center near connector 30).
  2. Ground the junction of R-476/Q-100.
  3. This will provide a very noticable decrease in switching time.

Warc modification

  1. In early TS-830's, the WARC transmit was not enabled.
  2. If this is the case, solder a jumper wire from Pin 12 of IC-23 to ground on the DIGITAL UNIT PCB. Ground can be obtained at Pin 8 of IC-4.

VFO-230 fine tune mod correction

A note published in your t/k newsletter of january, 1983, issue no. 30, concerning a fine tuning mod for the vfo-230, impelledme to purchase a new vfo-230 for the sole purpose of obtaining a slower dial tuning rate for my ts-380s. then the combination of a defective new vfo-230 and some bad information in your newsletter note triggered many, many hours of frustration and irritation over a period of several months starting in june 1986. i believe you should know about it when information in your newsletter causes frustration and irritation.

I decided to try the diode cutting bit again. it did not work. the optical dial encoder went crazy. i was ready to explode and did. Fortunately there was nobody around to hear me. back to the drawing board. now i know practically nothing about optical encoders but i do have an engineering background so i spent some time staring at the vfo-230 schematic in the ts-830s service manual. suddenly the light came on. ka0nnf gave you the wrong information about which diodes to cut. (his call is not wa0nnf as given in your newsletter note. i tracked him down by telephone. he told me he had sold the vfo-230 and couldn't remember.)

The proper diodes to cut for 6-1/4 khz per dial rev. are d19. d20, d22, d23, d24, and d26. i presume cutting diodes d19, d21, d22, d23, d25, and d26 would also work but i will leave that for someone else to try. in other words, of the eight diodes, cut all but d21 and d25 or d20 and d24 fpr 6/14 khz per dial revolution.
that7s the end of the story. my vfo-230 now works perfectly at 6-1/4 khz per dial revolution. this jpermits me to use the excellent ts-830s receiver on 160m cw with very extreme if (250 hz) and external audio (50 hz) seletivity. incidentally, i wonder how many repair facilities (including yours) are equipped to motor drive the vfo-230 dial shaft at 300 rpm while observing the optical encoder waveform? this alignment procedure is necessary, and is prescribed in the service manual, before you should expect the encoder to work at slower than the "stock" rate. (i think this was part of the problem).
TS-830S Low Voltage Supply Optional Improvements


Power supply drift and stability may be improved by these optional component changes and additions.

On the AF AVR unit X49-1140-00 (Vicinity of Q27-Q30) change:

R124 from 1K to 1.5K (RD14CB2E152J)*
R127 from 470 to 390 (RD14CB2E391J)*
R130 from 47K to 33K (RD14CB2E333J)#
D25 from WZ-061 to XZ-053 (V11-4101-60)*

*This will improve temperature drift from a maximum of about 100mV to a maximum of 1mV, and may be applied to any unit before serial # 201xxxx.

Add two 22 k ohm 1/4 resistors (RD14CB2E223J0, one each across Q30, and Q34, collector to emitter.#

#This will improve overall stability and may be applied to any unit before serial #105xxxx.

These changes are at the owners option and may not be performed in-warranty.
Kenwood TS-830 filter modification

Here is an easy filter modification for the kenwood ts-830s. first to use this mod, your rig need the yk-88c and to mak t even better, the yg-455c installed. in short what we are going to do, is move around a 9 volt switching voltage. this voltage comes from the af board, connector no. 7, pin no. 5. its marked rlr on the schematic. this voltage ends up at the pll assembly, connector no. 8, pin novp2. please do try this modification by cutting in this circuit at he source, because this same switching voltage feeds the if shiqo circuit, and the vbt circuit, and the pll. so cutting the wire at the af board will make the pll unlock when the mode switch is anywhere but in the cw positions. now to te prtceires.
  1. Remove the top and bottom covers, and turn the radio upside down with front facing you.

  2. Locate the mode switch, and on the middle wafer set of contacts, cut the white wire with the blue stripe. it is located next to the terminal with no conn ction, on the middle wafer set of contacts9)3-;3 about 1/4 inch ox wire on t switch contact, so youcan make a connection there later.

  3. You will need a another switch, one with at least three terminals, with the center teminal always in contact with one or the other of the outside contacts. its best to use a toggle type so you can mount it in one of the spare holes on the back of the radio.

  4. Splice into the wire removed from the moeoppcich, and connect this wire to the center of your new switch.

  5. From one (you select) of the side terminals of the new switch, connect a wire and run it back to the mode switch. connect this wire to t tminalon the mode switchnrom which you removed the white wire with the blue stripe. you did leave that 1/4 inch of wire didn't you? take care here, the grey wire next to the one you are working on carries 110 volts, so don't make any solder shorts!

  6. Now from the remaining terminal of your new switch, connect and run a wire to the if board to pins cw1-cw4. connect this wire to the green wire, that is connected to one of these pins. you will then have two wires connected to one of these terminals.

  7. Make sure tu have no solder shorts or bridges, make sure you have taped or insulated any bare wire connections. mount new switch in one of the spare holes on the baccof the radio. install the top aod bottom covers.

The modification works great, one position on the new switch and everything isnormal, in the other position the cw filter is placed in-line regardless of the position of the mode switch. to use the cw filters on rtty/amtor i found i had to turn the if shift control ccw to about the 9:30 position to center the tones in the passband. if you need an even narrower passband, just tighten it up a little with the vbt.

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