Modifications for the Kenwood TS-530

QRO Modification to TS-830S, TS-530S


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-530S 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 X49-1150-00 (Vicinity of Q19,Q20) change:

R68 from 1K to 1.5K (RD14CB2E152J)*
R72 from 470 to 390 (RD14CB2E391J)*
D14 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 Q19, and Q20, collector to emitter.#

#This will improve overall stability and may be applied to any unit before serial #201xxxx.

Note: These changes are at the owners option and may not be performed in- warranty.
TS-530S IF Unit Q2, Q7 Protection


High voltage transients at the receiver antenna can be felt in the ALC circuitry and cause a failure of IF unit transistors Q2 and Q7. Symptoms encountered bay be a loss of RX sensitivity, and or loss of S-Meter deflection.

Add the surge suppressor to the AF unit (X49-1150-XX) between terminal FG and ground, to prevent a reoccurance of this symptom.

Parts required:

Surge Suppressor ERZD03DK331

Time required for this modification is 1/2 hour or less.
TS-530 WARC bands

As supplied, the TS-530 will receive but not transmit on the three new warc bands. If transmit capability is desired, a minor wiring change is required.. There are just two minor changes that could be made and they are as fellows .......
  1. For all 3 bands break the line between the rf unit X44-1360-01 connector #6, pin #1 (top terminal) and AF unit X49-1150-00, connector #7, pin #4 (top terminal).

  2. Or, for individual bands on the rf unit X44-1360-01:
Band          Remove/cut
10 MHZ          D4
18 MHZ          D5
24.5 MHZ        D6

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