SB-833

TR-7800/TR-9000 Optional Ceramic Filters                    10-10-80


FM Adjacent channel rejection in either unit may be improved by installing an optional narrow ceramic filter.

Filter    Part No.       -6db Bandwidth -70db Bandwidth Retail
CFK-455F  L72-0304-05    +/- 6 kHz      +/- 12 kHz     $ 33.50
CFK-455G  (CFK-455G)*    +/- 4 kHz      +/- 10 kHz     $ 33.50

* Not original part.  No computer part number.

Location: TR-7800, RX unit X55-1270-10 part, L10
          TR-9000, RX unit X55-1260-11 part, CF1

To install, desolder the original filter and clear the second set of holes for the optional filter.  Solder the new filter in place. Be sure all pins are actually soldered, and that there are no solder bridges between pins or across the printed circuit board.  Clip the pins flush to the board, and reinstall the circuit board.

Note:  Squelch operation will vary from unit to unit with an optional
narrow filter.  Tighter coupling from the detector  to the squelch circuit may be tried to restore "original feel".

JEB/yn
(c) 101080TKC
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                 SSB low power on the TR9000
                 ===========================

There is a very easy mod for the TR9000 to make it operate on low power on SSB. It consists of cutting just one wire!

First remove the top half of the case, then locate the back of the power switch. With a pair of cutters cut the ORANGE WIRE (there is only one wire of this colour) and insulate it. Thats all there is to it!

Your 9000 will now operate on low power on both FM & SSB.


PORTED AND REALIGNED FROM PC TO AMIGA FORMAT BY BOB G0LBQ - N6XDI.