[ICOM] FL-223 in an IC-765 ?

[Adam Farson]

Hi Jay,

What I did in the IC-781 was replace the stock FL-102 AM filter with the
FL-223, using the procedure outlined in the user manual for installing the
FL-103 wide SSB filter. 

http://www.mods.dk/view.php?ArticleId=1589

If you try to use the FL-223 with the FL-96 (455 kHz, 2.4 kHz BW) and the
PBT Mod, the Passband Tuning will not work properly, as the filter passbands
will be severely mismatched. The link below refers to Twin PBT, but
single-knob PBT has the same requirement for reasonably close filter
matching.

http://www.qsl.net/icom/xfilter.html

I normally recommend replacing the FL-30/FL-96 pair with an FL-80/FL-44A
pair for -6 dB BW = 2.4 kHz and a good shape factor. (The Inrad 109 is a
near cross to the FL-44A). With these filters, the PBT will allow you to
narrow the IF bandwidth significantly, although there will be some
degradation of shape factor as the PBT is offset from the centre position.

If you are satisfied with having only a 1.8 kHz SSB bandwidth, you can
replace the FL-30 with the FL-223 - but this filter should be paired with an
FL-222 or an Inrad 322 to ensure correct PBT operation.

I have assumed throughout that you have done the W2ISB PBT Mod. This
modification is a "must". It is described in Don, VE3HUR's IC-756 Notes
(http://www.qsl.net/icom/manuals.html)

Hope this helps.

Cheers for now, 73,
Adam VA7OJ/AB4OJ



-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of radio_q at juno.com
Sent: 22 July 2004 18:17
To: icom at mailman.qth.net
Subject: [ICOM] FL-223 in an IC-765 ?

Hi Group

I was reading a recent note from Adam where he indicated he put a Fl-223
into a IC-781 to tighten up the SSB response. 

I have an extra FL-223 in my Icom Box of stuff and that got me to wondering
if I could put it into my Icom IC-765.  It appears to have the same
frequency, 9.0115 as the filter that is in there according to the service
manual.  It also looks to be the same physical size from looking at the
photographs.  I have not taken the top off yet to give it a closer eyeball
but wondered if anyone had done that or knows why it could not be done.

Thanks for any inputs

Jay

________________________________________________________________
The best thing to hit the Internet in years - Juno SpeedBand!
Surf the Web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!
----
Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom Users
Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: http://www.qsl.net/icom/