Option Installations - Icom IC-756 Instruction Manual

OPTION INSTALLATIONS 9
E Optional IF filters
Several IF filters are available for the IC-756. You can
install 2 filters for 9 MHz and 455 kHz IF. Choose ap-
propriate filter(s) for your operating needs.
9 MHz optional filter
9 MHz optional filters:
FL-100 CW NARROW FILTER 500 Hz/-6 dB
FL-101 CW NARROW FILTER 250 Hz/-6 dB
FL-223 SSB NARROW FILTER 1.9 kHz/-6 dB
FL-232 CW NARROW FILTER 350 Hz/-6 dB
455 kHz optional filters:
FL-52A CW NARROW FILTER 500 Hz/—6 dB
FL-53A CW NARROW FILTER 250 Hz/-6 dB
FL-222 SSB NARROW FILTER 1.8 kHz/-6 dB
FL-257 SSB WIDE FILTER 3.3 kHz/-6 dB
455 kHz optional filter
@ Remove the top and bottom covers as shown on
the opposite page.
© Turn the transceiver upside down. Install the de-
sired filter as shown in the diagram at right.
¢The 9 MHz filters can be installed in either direction.
(3) Replace the top and bottom covers.
| Y NOTE: After filter installation, specify the installed
% filter using set mode. (p. 55) Otherwise, the in-
p stalled filter will not function properly.
W CR-502 HIGH STABILITY CRYSTAL UNIT
By installing the CR-502, the total frequency stability
of the transceiver will be improved.
Reference freq. check point
@ Remove the top and bottom covers as shown on (cable from J81; 60.00 MHz)
the opposite page.
(@) Turn the transceiver upside down. Remove 6
screws from the PLL shielding plate, then remove
the plate.
(3) Cut the leads of R56 and L55 (in a shielded box)
on the PLL unit.
@) Put the CR-502 in the space available as shown in
the diagram, then solder its feet into place (6
points).
© Adjust the reference frequency using a frequency
counter.
©) Return the shield case, shield plate and top/bottom
covers to their original positions.
CR-502 frequency stability: +0.5 ppm
(-30°C to +60°C;
—22°F to +140°F)