[Premium-Rx] Racal RA3791 address

[John Nelson]

In case any other RA3791 users wish to change the address of their receiver
or make it non-addressable, the following appears to be valid for firmware
version P90550/08. 

It turns out that the "address" is the address of the tributary port, which
is set via the octal DIP switch SW3 on the digital board. The settings are
shown on page 13-4 of the maintenance manual. The receiver can also be made
non-addressable via the setting of SW4-8 as shown on page 13-5. If this is
set to OFF, both the numeric address and associated caption disappear from
the left-hand side of the LH display. 

Happy new year to all, especially Racal enthusiasts... 

73 John
GW4FRX