Hello All,
A common problem when using a KAM-Plus multimode with the
Kenwood TS-850 or TS-450 occurs when the KAM-Plus is coupled to
the Accessory-2 socket on the back of the transceiver, producing
noticable distortion of the transmitted audio when using the
microphone in SSB mode..
The problem is easy to cure by disconnecting the Accessory-2
plug from the back of the tranceiver, but this meant moving the
transceiver around every time one wished to operate on SSB..
The problem is caused by the input sensitivity of the rear
Accessory-2 socket being set to high, so that it picks up very low
level noise from the KAM-Plus and associated computer wiring, this
mixes with the microphone signal, to produce the distortion.
The cure is to reduce the input sensitivity of the radio,
thus reducing the chance of distortion, also it goes without saying
that the output from the KAM-Plus must be increased to compensate
for this.
With both the TS-450 and TS-850, adjusting the input sensitivity
is straight forward and the transceiver manuals show you the appropriate
control and its location.. This is in both cases VR18 to be found on
the main board of the radio,(refer to manual) in practice I found that
it was best to adjust this control fully counterclockwise..
Then we need to adjust the output from the KAM-Plus by varying
potentiometer R28 and setting removable link (K9), this link is factory
set on one post only, (in the open position)!! this should be connected
shorting the two posts, thus putting the KAM-Plus into the high output
position, and then potentiometer R-28 is adjusted to give full power
out from your HF radio with very little ALC deflection, when the MIC
gain is in the normal operating position..
Then I am sure you will find that your problem is over, you can now
simply change from digital modes to SSB.. Remember if you have your
Beacon activated to turn it OFF or it could cause a few comments when
operating SSB..
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