 TS-790 MODS de SM0TER

Subject:        INSUFFICIENT TRANSMISSION TALK POWER IN SSB MODE.

Extracts from KENWOOD Service Technical Report
         No. E51-89-002 date FEB 10 1989

The talk power of the TS-790 is lower than previous models i.e. TR-851 and
TS-811.

Not all versions of the RIG suffer from this problem. I have the TS-790A and
the following modification was done when I purchased the RIG.

The report was sent to the following TRIO-KENWOOD offices.

T-K CANADA
T-K AUSTRALIA
T-K NV,SA

The following is quoted from the Service Report.


To boost the talk power of the TS-790 to almost the same level of the former
models surpress the ALC response like the former models.

Connect a 0.039 to 0.047 uF between pins 6 and GND of IC201 on the ALC
amplifier daughter unit (X59-3480-00 (F)).

*NOTE: This above alteration distorts the SSB transmission signal quality.
       Thus the alteration will not be applied to mass production.

End of quote.

The mode was done on my RIG from the factory and I have had no reports of
poor audio!!

The following white noise check is shown in the Service Report.

                        ORGINAL                        ALTERED
Low ALC level          1 to 1.5 W                    2.5 to 3.0 W



 How to use TS-790 on CW-MS !
   The TS-790 doesn't behalf as expected for speeds over 700 LPM. In order to
eliminate this limit just remove the condenser C221 in the STBY unit.
STBY (A) (X59-3480-00 (G)). This is a very little SMD conderser.
   After beeing removed the TS-790 will work pretty well at higher speed (it
has been tested up to 1200 LPM).
   The modification is quite simple, but anyway, if you have trouble finding
the mentioned condenser send me a SASE and I'll send you back a diagram.

   I want to thank Enrique EA2LY/4 who kindly passed to me this information.

   Best 73 and good luck with the TS-790. Gabriel EA6VQ @EA6URP.EAPM.ESP.EU
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