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FT736R.6

Subject: FT736R - VHF Attenuator Mod

A little trick to built in an RX-Attenuator in the FT736R (VHF Band)

Heìlo FT736 fans,

Using a preamp in the VHF Band causes sometimes trouble with noise on
this band. The S-Meter readout 2-4 without any signal. The AGC is
working only to reduce the noise.
A simple trick decrease the sensivity for about 6 dBm.

Look in the schematic-diagramm 144 MHz MAIN-UNIT. The first RX-Stage
is at the left side of the sheet. Locate the transistor Q01 3SK122L
and look at the source-resistor R02 (47 Ohm). A second resistor with
the value 1.2 KOhm in series with R02 decrease the sensivity for 6 dB.
Using the preamp-switch (this switch has a free row) You can easyly
switch between attunation and normal use by making a bridge over the
new 1.2 KOhm Resistor with this contacts.

I think, this trick is not a excellent way of a RX-Attunator, but it
works ufb here in my rig.


By the way, remember of loosing warrenty bù modify Your rig !  I am not
responsable for failures after modification !

                         Vy 73 de Guenter DD9ZO @ DB0SIF

 

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