rjr@mgweed.UUCP (Bob Roehrig) (09/06/84)
The following is a list of favorite changes that can be made to the
Kenwood 930. These changes are quite simple and do not require the
addition of any switches.
NOTE: In the operator's manual supplied with the 930, there is an error
on one of the drawings. On the upper left corner of the DIGITAL UNIT
schematic locate connector 8. The lead designations are as follows (note
that some of the designations do not appear on this sheet so you can add
them to the drawing):
Pin Desig.
1 100
2 MU
3 SCN
4 M2
5 MIN
6 FSK
7 B2
8 FT
On the main drawing, called SCHEMATIC DIAGRAM, the pin numbers shown on
connector 8 are reversed from the way they are numbered on the DIGITAL
UNIT schematic. In the following changes, I am assuming that the
numbering on the DIGITAL UNIT sheet is correct. In any event, it will be
obvious which end is which since the end pin is vacant.
CHANGES
1) The resolution of the main tuning digital readout can be increased
from 100 Hz to 10 Hz. No digits are lost since the readout has the extra
digit for this purpose. This change is accomplished by grounding pin 1
of connector 8 on the DIGITAL UNIT.
2) The tuning rate is 10 kHz per revolution of the main tuning knob.
The tuning rate can be changed to 5 kHz per revolution by cutting one
end of diode D-13 on the DIGITAL UNIT.
(Note that the black marks on the tuning knob itself are exactly 500 Hz
apart. The knob can be "corrected" by tuning in an exact frequency, for
example 10,000.00 kHz, pressing the DIAL LOCK switch, then turning the
knob to line up a black line. As long as you don't spin the dial too
fast, it will track nicely from one end to the other. With the slow rate
modification, the dial increments become 250 Hz per division).
You may desire to switch this reduced tuning rate on and off. For
example, you can select the new rate on just VFO B by using an unused
section of the "FUNCTION" switch. Another possibility is to use the
display "DIM" switch.
3) There are an additional 8 memories available. These can be obtained
by grounding pin 5 of connector 7 on the DIGITAL UNIT. (This lead is
designated "M3").
The 8 additional memories can be selected by using an unused contact on
the "FUNCTION" switch.
4) Each group of 8 memories can be scanned at a rate of about 1 per
second. Unlike a normal scanner, The unit will not stop scanning when a
signal is present, but it is a good way to search favorite frequencies
for activity.
A method of turning on the scan function without affecting normal switch
functions would be to wire the unused section of the DIAL LOCK switch in
series with the unused section of the METER switch (meter switch in the
"VC" position).
5) A handy option is to be able to momentarily unlock one VFO when the
DIAL LOCK is on. This can be useful during split frequency operation
when you want to keep the receive vfo locked (the DX station's xmit
freq), yet quickly qsy to the frequency he is listening to with your
transmit VFO.
This change can be made by wiring one lead from the DIAL LOCK switch in
series with extra normally closed contacts of the "T-F" switch.
6) This change permits automatic disabling of a linear amplifier during
full break-in cw operation. This is desirable since the relays in a
linear cannot properly follow each keyed character element. This change
should also be done if AMTOR operation is contemplated.
Assuming that your 930 has the aux. relay board in it, merely wire the
+28 volt lead to the relay coil in series with the extra contacts of the
"FULL-SEMI" switch.
7) For AMTOR operation, the T-R switching speed must be increased.
2 suggested changes are to remove C-500 (4.7uf) on the SIGNAL BOARD
(located top center near connector 30), and to ground the junction of
R-476 / Q-100.
8) In early units, the WARC band transmit was not enabled. If this is
the case, solder a jumper from pin 12 of IC-23 to ground on the DIGITAL
UNIT. (Ground can be obtained at pin 8 of IC-24).
9) Transmit can be enabled on all frequencies between 1.5 and 30 MHz for
MARS and transverter use by adding two jumpers on the DIGITAL UNIT:
Connect pin 9 of IC-11 to pin 12 of IC-21.
Connect pin 9 of IC-12 to pin 12 of IC-22.
========================================================================
Additional comments:
Even though the receiver low frequency end is spec'd as 150 kHZ, it will
operate down to 100 kHz. [A[BTo conveniently switch in a general purpose
receiving antenna you must use the transverter connector. When the 8 pin
DIN plug is plugged into this connector, a switch operates which
separates the coaxial antenna input from the receiver input. These two
connections appear at pins 8 and 5 resp. of the transverter connector.
(This 8 pin DIN plug is not furnished with the 930). The most
convenient setup is to bring cables from both the REMOTE and TRANSVERTER
connectors into a junction box which has appropriate connectors and
switches on it for interfacing to a transverter, receiving antenna,
linear amp, etc.
Here is a chart of the connections to these connectors:
REMOTE (7 pin DIN) XVERTER (8 pin DIN)
1 Speaker output 1 Grd
2 Grd 2 +V out on xmit*
3 PTT 3 Grd
4 Q-22 out** 4 XVRT ON/OFF Control***
5 unused 5 Receiver input
6 ALC input 6 XVRTR ALC input
7 XMIT RELAY** 7 Xmit RF to xvrtr input
8 HF ant in
* A 12 volt, 50ma max. relay may be connected from pin 2
to ground. This relay will operate on xmit.
** Original units used Q-22 collector for linear amp relay
control. This did not work with low voltage relay systems
or those using a negative voltage. An optional relay board
(Now supplied in all units as standard) is available and
provides a normally open contact closure to ground at
pin 7.
*** Pin 4 is grounded to enable xvrtr operation. This may
be done by a switch in the transverter itself.
========================================================================jhs@Mitre-Bedford@sri-unix.UUCP (09/17/84)
If you run across a mod to make the 430 read out true frequency like a counter instead of its own whimsical interpretation of frequency, I would be most interested in hearing about it. As I noted in an earlier comment, the Kenwood TS430-S reads out from a ROM which translates dial rotation into what it thinks the frequency might be (approximately) for that dial rotation. It can be 200 Hz off or maybe more, even though it reads out to 10 Hz. If there is a hardware failure, it could be anywhere, while still reading out an "in-band" frequency. I hope the 930 is better designed. Incidentally, if anybody cares, I have a mod for better CW keying for the TS120-S and TS130-S. If you do high speed CW work, it really makes an improvement. -73 de W3IKG John Sangster jhs at MITRE-Bedford