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3. This will provide a very noticeable decrease in switching time.
9.2
WARC modification
In early TS-830's, the WARC transmit was not enabled. 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. (KF2TZ)
9.3
RIT / XIT modifications
(from Ed Sanders W4XC, QST Jun 1982)
To extend the RIT/XIT control tuning range to +/- 8 kHz, two ¼-W carbon-composition
resistors are needed. A 160 Ohm resistor is placed in parallel with R17 (6.8 kOhm), which is
located at the rear of the RIT/XIT control potentiometer. R87 (10 kOhm) is paralleled with a
2.7 kOhm resistor. This can be done without remove the AF board by connecting the resistor
between the right side of VR2 and the terminal marked TPG.
Recalibration RIT control is accomplished by centering the control knob and noting the
frequency displayed on the readout. Turn RIT on and adjust VR2 until the frequency noted
previously is displayed.
9.4
VFO-230 fine tune mod
A note published in your t/k newsletter of January 1983, issue no. 30, concerning a fine tuning
mod for the VFO-230, impelled me to purchase a new VFO-230 for the sole purpose of
obtaining a slower dial tuning rate for my TS-830S. 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 revolution 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 for 6/14 KHz per dial revolution.
That's the end of the story. My VFO-230 now works perfectly at 6-1/4 KHz per dial revolution.
This permits me to use the excellent TS-830S receiver on 160 m CW with very extreme IF
(250 Hz) and external audio (50 Hz) selectivity. 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).
9.5
TS-830S Low Voltage Supply Optional Improvements
(Author: Trio-Kenwood Communication, Inc.)
28
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