[ICOM] Icom filter question

[Adam Farson]

Hi Frank,

Interesting. I am pretty certain that the newer 9 MHz filters (FL-223 etc.)
are MCF's, so "assumed" that the FL-80 was also an MCF. That is quite a tour
de force, packing discrete crystals (how many were there?) and chip caps
into that wee case!

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 Frank A. Ellis
Sent: 11 December 2004 11:03
To: ICOM Reflector
Subject: RE: [ICOM] Icom filter question

Hi Adam,

Good info. FYI, I have an FL-80 here that I disassembled some years back, as
one of the sections shifted up about 200 Hz. The symptom was a tonal
difference with no signal between USB and LSB, and the PBT was perfectly
aligned. A new filter cured the problem. I disassembled it as I was curious,
and found discrete crystals and chip caps (the "matching network"). So,
perhaps not all of the 9 MHz filters are monolithic? 

73 Frank W3UHF



--- Adam Farson <farson at shaw.ca> wrote:

> Hi Frank,
> 
> In fact, the Icom 9 MHz filters (and the high-IF roofing filters) are 
> monolithic crystal filters (MCF), whilst the 455 kHz filters such as 
> the FL-44A, FL-52A etc. use discrete crystals with matching networks.
> 
> Cheers for now, 73,
> Adam VA7OJ/AB4OJ
>  


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