Modifications for the Kenwood TS-530



19-07-1998 QRO 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)



19-07-1998 TS-530S Low Voltage Supply Optional Improvements
Author: Trio-Kenwood Communication, inc.


Service Bulletin no. 848 (30-7-1981)

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

On the AF AVR unit X49-1140-00 (Vicinity of Q19-Q20) changes: 

R68 from 1 Kohm to 1.5 Kohm  (RD14CB2E152J)
R72 from 470 ohm to 390 ohm  (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 10 mV, 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.



19-07-1998 TS-530S IF Unit Q2, Q7 Protection
Author: Trio-Kenwood Communication, inc.


Service Bulletin no. 878 (25-8-1983)

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.



19-07-1998 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
I did the first modification and found it to be the best way to go, good luck and happy hamming !

de KC2AR Bob in STARRUCCA,PA.