Nokia RD40 Manual page 40

R40 Modifications
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lNokia R4Ol IHardware] [Identification] [Dismantling] [PBR]
Nokia R4O Modifications
The R4O is by nature a trunked radio but can be modified for
conventional operation on amateur freouencies.
VCO Adjustment
T h e R 4 0 a D o e a r s t o h a v e a n u n u s u a l
method of tuning the VCO.
There's what looks like an RF modification
shown on the PI4VAD site (see link below)
but it's actually to tune the VCOS. I'm not
sure if this is necessary for ex-gasboard
models but the VCO will happily lock
w i t h i n a 1 0 l 4 H z b a n d w i d t h .
The method is to put the radio into service
mode, selecting the bottom of the
required band, then the top of the
required band and check that each VCO is
reading within parametêrs on each
respective testpoint whilst either receiving
or transmitting as appropriate.
T h i s
photo shows on the right hand corner the
underside of the RF board. The PCB track
is tuned by physically modifying it with a
d r i l l , o r l i n k i n g w i t h s o l d e r i n g .
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