BC100 Scanner Mods

[Charger383]

BC100 Modifications



The Uniden Bearcat 100 XL is a beautifully made receiver which covers 66 - 512

MHz (with gaps). It can receive both AM and FM signals, but you cannot

select which you want: the receiver selects AM on the air band (118 - 136 MHz)

and FM everywhere else. The following simple modification will allow you to

select AM or FM independently of the frequency, by means of a 3-position

switch. The three settings are: AM; FM; auto. (viz. AM on the air band, FM

everywhere else).



Remove the battery cover. Unplug the ribbon cable at the bottom end of the

receiver, and pull out the microprocessor (uP) board, which is also the front

panel. Label the 12 wires of the ribbon cable 1 to 12, starting from the

left, with the component side of the uP board towards you. Wire 2 is Vcc

(about 7 V), wire 12 is ground, and wire 8 is the signal which goes from the

uP to the receiver board to select AM or FM operation. It is 0 V (or open)

for FM, and Vcc (approx.) for AM.



Unsolder wire 8 from the board, removing excess solder with a solder-sucker

or wick. Obtain a single-pole change-over toggle switch with centre "off",

and connect as follows.



from wire 8 on uP board ______@

@---@_____ to wire 8 on Rx board

from wire 2 on uP board (Vcc) ______@ (AM/FM select)



Use heat-shrink sleeving or plastic tape to insulate the connections.



The switch can be mounted on the battery cover, or perhaps -- if you can find

a small enough switch -- on the top panel, next to the "lock" switch.

</p>