Wednesday, December 1, 2010

Yaesu VX-7r Service Mode Setup

If you are fairly competent, AND have the correct test gear (spectrum analyzer etc), it is quite a straightforward task to put the Yaesu VX-7r into 'Service Mode', to make any adjustments.
From the service menu, you are able to make adjustments to power levels, modulation levels, deviation levels and several others.
When the service menu first appears, the window will show 'PLL REF'.
UNDER NO CIRCUMSTANCES SHOULD YOU CHANGE THIS VALUE! -
YOU HAVE BEEN WARNED!

If you intend to make any changes to default levels on your VX-7r, it goes without saying that you MUST write down ALL settings BEFORE adjusting them!

A quite common complaint of VX-7r users, is the CTCSS, or rather it's nasty habit of being slightly overdeviated, appearing as an annoying hum on TX.
This value can easily be set in the service menu.
If you feel that the low power setting is too high or low, you can adjust the setting for all 4 power levels, band by band.


Service menu includes :
PLL reference frequency
Squelch Hysteresis Adjustment
Squelch Preset Threshold
Squelch Preset Tight
SMeter
s1 adjustment
S meter full scale adjustment (S9)
Wide FM S meter S1 adjustment
Wide FM SMeter
full scale adjustment (S9)
TX power levels, all 4 bands
******TX DEVIATION ADJUSTMENT**** which is, by the way,
set at the factory to 4.2 kHz for the USA and to 4.5kHz
everywhere else
CTCSS TX level adjustments
DCS TX level adjustments

Picture courtesy of XU7ADQ


Picture courtesy of XU7ADQ

REMEMBER TO WRITE DOWN ALL THE SETTINGS BEFORE CHANGING THE VALUES!

DO NOT CHANGE THE 'PLL REF'

I CANNOT BE HELD RESPONSIBLE FOR ANY DAMAGE CAUSED BY PERFORMING THE ABOVE PROCEDURE

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