[ICOM] Icom filter question

[Frank A. Ellis]

Hi Adam,

Well, I dug it out and counted 'em - 6 crystals on the
top side of the PCB, and about a dozen chip caps on
the bottom (foil) side. The bottom side of the board
has the 2 sets of pins that go thru, and are soldered
to, the filter baseplate. The baseplate is sandwiched
to the PCB, and the edges of both get soldered to the
can wall during assembly.

I would assume that all of the other "older" ICOM 9
MHz crystals (FL-30, FL-45, FL-54, etc.) were also
made in this fashion, unless the FL-80 is just an
aberration!

BTW, have you heard anything from Bill Diamond
recently?  It has been strangely silent from his neck
of the woods for awhile.

Bill, if you are copying, drop us a line and let us
know how you're doing.

73, Frank W3UHF





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

> 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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