Modifications for the Kenwood TM-732
AIR CLONING (Does not work in K1 or E1 Mod modes)
This procedure allows you to clone a second transciever as above,
over the air. The data is transmitted automatically using DTMF
tones. During transmission (which is one-way only), the master
will automatically switch to LOW power. To be legal, use only a
UHF cloning frequency.
This procedure is not enabled in the stock transciever. At a
minimum, you must cut the green wire to make iwork.
Configure master transciever's memories as desired. Select
UHF simplex transmit frequency and set PTT to UF H(will work on
VHF but is not recommended).
Switch the power OFF. Press and hold the CALL and DTSS tutons
and turn the power back ON. "CLonE" appears in display.
Set the receive frequency on the slave transciever the same
as that of the master. Turn power off, hold down call and dtss
keys and turn power on. 'clone' appears in display.
Press the ptt on the master's microphone. Data transmission
will begin. In case of a receive error, the slave transciever will
display 'err'. when the prcedureo is complete, both radios will
PAGING ANSWERBACK (Does not work in K1 or E1 Mod modes)
The exact operation of this feature is unclear but the folling
description has been given:
When enabled, documentation says: "If a maching code is received
and the other transciever is no longer BUSY, the code of the local
transciever is sent to the other transciever. The answerback
function then turns off."
To enable, hold down the F key and press the TONE key.
Do disable, repeat step 1
(requires DTMF microphone)
(Documentation of this "feature" is diffiult to comprehend but
perhaps someone will figure out what it does.. I suspect that
"RECOVERY" refers to returning the memories to their original
state after changing the split memory layout.)
Hold down F and C.SEL, turn on power
Press D, followed by 7 on the microphone. "Inspection Mode"
is now enabled.
To cancel, press and hold F and then C.SEL
Before recovery, the memory channels must be returned to
the previous state (number of split memories, etc.)."
Being a TM-741 owner, there were a couple of things that I
mied on the 732. First, there's no real-time clock, no sleep
timer, no programmable ON time/ OFF time feature. There is an
APO (automatic power off) with a preset time of 2:59:00 of
inactivity until power down.
Another complaint is the slow scanning speed. The unit will scan
VFO or memory at no more than about 5 channels/frequencies per
second per band. I consider this to be terribly slow in today's
age. The slowness is probably due to the fact that the remote
contains all of the scanning logic and because the data path
between the head and the base is over a 2 wire serial data stream.
Anotherp erennial complaint is that the radio does not cover
the entire UHF frequency band of 420-450 Mhz. As shipped,
the unit will only operate over the range from 438 to 450,
(transmit or receive) which I find objectionable.
The manual is of typical quality and fairly complete although
not well indexed. There are so many functions that a cheat
sheet is needed but as mentioned, was sadly not included. In
typical fashion I note that the Japanese have never been able to
adequately and clearly explain how DTMF Squelch and Paging
works. They've tried diagrams and jinglish explanations but in
the end you still end up reading the instructions over and over
before you fully understand them. I'd love to see a plain
English discussion of how the DTMF features are intended to work
and how they really work in practice. Fllow that with a step
by step example and we'd probably have something that could be
One of my reasons for buying the radio was to use the remote
mounted head option. The option, the PG-4K kit, is advertised
as a 13 foot extension. What you don't find out until you buy
it, however, is that only the display cable is 13 feet long and
the microphone cable is only half that! To me this meant that
although the display cable would let me trunk mount the base,
there was no way I could get by with a 6 foot microphone cable.
The solution: buy the PG-4M(?) which is the longer model for
another $30! Needless to say, I'm not a happy camper! Are you
On a positive note about the remote cabling, at least with the
732 it is possible to roll your own. The 4 conductor head to
chassis connector cable could be easily spliced and extended, and
an ordinary RJ-45 extension cable could be used for the
microphone. For many folks, however, it's probably easier
to just buy the short ($47) or the long ($78) cable kit.
The extension cable issue aside however, it still looks like it
will be a very good radio. As always, after spending a big wad
of cash I'm automatically inclined to say that I like the
radio. This is no exception, the TM-732 does a fine job at
heading off the competition at a good price-performance point.
The price is the same as the older TM-731 which was around $650
retail (real price, not the bogus MSRP).
To conclude, I think Kenwood has come up with a fine replacement
for the 731, and has put a lot of thought put into the design of
Kenwood has done a fairly good job at maintaining a consistent
user interface between their models. Being familiar with the
241 and 741, I found it pretty intuitive to operate. Not
intuitive enough, however, to venture out of the house without
taking the operators manual along since they sadly omitted a
quick reference card (like the give out with the 741). Unless
otherwise noted, the 732 generally has the same basic feature
set as the TM-241 plus several extras.
The following is an unordered list of outstanding bits of trivia
regarding the 732's features:
1. Dual In-Band Receive: Competitive pressures (e.g. Icom's
2410) has now made this a standard. You can set the display to
receive any combination of: VHF/UHF, VHF/VHF or UHF/UHF. This
capability is quite well engineered and makes it possible to
transmit as well as receive on either band's second display. It
is not possible (understandably) to have a full duplex QSO on an
in-band setup. In other words, when you set the radio to
monitor two UHF or two VHF frequencies, one of these frequencies
is muted when you transmit on the other. This is not so when
the selection is VHF/UHF, where the receiving band is not mut
Looking at the schematic, the dual in-band receive is well
implemented with each of the transceiver boards having two
receiver front end units (RF amp and mixers), one for each
band. There are some unsymmetrical aspects to the dual in-band
receive. First, the UHF receiver does not have an AM mode which
means that you cannot monitor AM aircraft spectrum at 118-136
MHz with the UHF receiver. Similarly, you cannot monitor 800
MHz with the VHF receiver. Each of these modes AM aircraft and
800 MHz, are unique to the VHF and UHF receivers respetively.
A nice touch is that even though the second receiver is utilized
on the other band, the transmitter is automatically switched
back to the proper band which allows you to transmit on either
of the two frequencies while using the dual in-band mode.
2. Smart Mute: The MUTE function is now intelligent in that it
mutes the non-PTT band only when necessary. This means that the
audio muting (actually, 20Db of audio attenationu) is switched
into the auxiliary band only when something i being received on
the primary band. Previous Kenwood rigs muted the auxiliary
band at all times when the MUTE function was active.
3. More programmable microphone function keys: Previous
Kenwoods allowed you to program the PF mcrophone key only.
With the 732, you may program any of ttop 4 function keys
(CALL, VFO, MR and PF), even for example, with such multi-key
sequences as [F][VFO].
4. New Display Lighting: The display is the now-standard black
letters on a light background. Like the 741, it has 4 light
levels, plus OFF (no light) which is interesting. Also, there's
a special feature which when enabled mkes the display jump up
to the next brighter display level whenever a button or key is
pressed, returning to the dim level after 5 seconds of
inactivity. When used with the OFF level it gives you a display
which is completely dark at night and comes on only when you
need it. There is, however, a small green LED off of the
display which remains lit at all times to show which band is in
5. Memory: As advertised the radio comes with 25 full-however,
is that you can have up to 64
memories if you are wiling to forgo the odd-offset capability
to varying degrees. For example, if you can live with only 5
odd-offsets then you'll get 30 memories per band. If you don't
need any odd-offsets then you get 32 memories per band. In
addition, you can apportion the 64 available slots between the
two bands in whatever ratio that you desire (in 5 channel
increments). In other words, you can configure for 50 UHF
memories and 14 VHF memories if you like.
M 22 21 20 19 VHF UHF SHIFT 800 REMARKS
K1 0 1 0 1 144-148 438-450 .6/5 STD. US VERSION
K2 1 1 0 1 144-148 438-450 .6/5 X US AFTER GREEN WIRE
K3 1 0 0 1 142-152 420-450 .6/5 XF MARS/CAP MOD
K4 0 1 1 0 136-174 410-470 .6/5 X ALL BAND MOD
M1 0 0 0 0 144-148 430-440 .6/5 GENERIC INT'L MODEL
M2 0 1 0 0 136-174 410-470 .6/5 X ALL BAND INT'L (430
E1 0 0 1 0 144-146 430-440 .6/(1.6) STD EUROPE MODEL
E2 1 0 1 0 136-174 432-438 .6/1.6 X DENMARK
E3 0 0 1 1 144-146 410-470 .6/(1.6) X
E4 1 1 0 0 144-146 430-440 .6/(1.6) X
E5 1 0 1 1 136-174 410-470 .6/(1.6) X EUROPE ALL BAND
C1 0 0 0 1 136-174 340-512 5.7/10 CHINA MODEL
0 = RESISTOR IN 1 = RESISTOR OUT
All 'resistors' o ohms (wire jumper ok)
Green wire is equivalent to R22 - present in K1 model
Press ENTER to continue (A to abort) -->
0 = RESISTOR PRESENT, 1 = RESISTOR ABSENT
Standard shifts in MHz VHF/UHF. those listed as (1.6) also DO -7.6
Codes not listed are used in japan version, special cpu required
M Column is factory mode number
K2 mod includes 410-770 receive and enables cloning feature
to perform any of these mods, remove the back cover from the remote
head unit. Resistor numbers clearly marked on board along top.
800 MHZ RECEIVE
To enable 800 receive, switch to uhf vfo (not available in uxu),
press and hold mhz button until 800.000 appears.
A capacitor must be added (c348) to enable the 800 receiver.
to add, remove uhf transciever board and next to the pad of n 1
of ic-202 (on the foil side), add a 2.2 pf chip capacitor.
a wire can be used instead of the capacitor but sensitivity will
be reduced. (see schematic diagram for reason).
(works in all confguration modes)
This procedure allows you to clone the entire memory of a 'maer'
transciever into the memory of a 'slave' transciever.
First, construct an rj-45 jumper cable as follows:
UP ----------------------------- UP Note that ptt and down
E ----------------------------- E are crossed end-to-end
PTT ----------------------------- DOWN
DOWN ----------------------------- PTT
For hacker's reference: UP=CLK, PTT=SO/, DOWN=SI
Configure the master transciever's memories as desired.
Switch power off, hold down f and mhz keys and switch
power back on while holding keys. Display wi show 'clone'.
Set the slave transciever in the clone mode (as in step 2).
Plug the cable into the two radios (which end does not matter).
Press the call button on the master. When 'end' is displayed,
operation is complete.
TM-732 gets hot
De Fan on the backside doesn't work correctly.
Solder a transistor (eg BSX20) clote to the Fan-connector:
Collector: to the Fan-connector (closest totthe 12V-wire)
Emmitor : to GND
Base : to 7808 regulator (closest pin to the Front)
The Fan will now operate whenever the transceiver is switched on.
AM detector control
The AM Detctor, which automatically comes on below 136 MHz, can be
forced ON at any VHF frequency by pressing the F and MUTE keys
while applying power. Radio continues to transmit FM but receives
AM. Changing frequencies or memory channels will cancel the forced
AM mode. This capability could be useful for listening to the
USAF Thunderbirds which sometimes operate in the 143 MHZ band using AM.
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