[ICOM] Wanted: Narrower (than stock) SSB filter for IC-735

[D C *Mac* Macdonald]

Inrad makes two at the 9 MHz I.F. for $115;
 
#123 for 2.8 kHz
#320 for 1.8 kHz.
 
They make four at the 455 kHz I.F. for $170;
 
#124 for 2.8 kHz
#109 for 2.4 kHz
#314 for 2.1 kHz
#322 for 1.8 kHz
 
I guess it's tougher to build filters at 455 than 9,000 kHz???
 
Are the 455 kHz filters better than those at 9 Mhz? I checked
the data sheets and noted that several of the 9 MHz filters
had noticably more ripple across the tops of their slope curves.
 
The 123 appears to have just a bit sharper cutoff than the 124
but the 320 is a miniscule amount wider than the 322.
 
I have located a new 109 (2.4 kHz) filter, but the asking price
is $140 which is about half of a bare 735 is current sell price.

* * * * * * * * * * *
* 73 - Mac, K2GKK/5 *
* (Since 30 Nov 53) *
* Oklahoma City, OK *
* USAF, Ret (61-81) *
* * * * * * * * * * *

 

 

> Date: Sun, 21 Aug 2011 18:25:51 -0700
> From: gfiber at comcast.net
> To: icom at mailman.qth.net
> Subject: Re: [ICOM] Wanted: Narrower (than stock) SSB filter for IC-735
> 
> I want to say the FL-30 was the original SSB filter nut would have to 
> find a print and have a look. I suspect one of your choices will be 
> Inrad but it will not likely be a drop in, you may have to use some 
> RG-174 to connect it up and some double stick tape to mount it. 
> Possibly W4RT has a collins mechanical filter that would work too. I 
> don't think the Icom FL-223 1.8 KHz filter will work as the impedance 
> for the filter is likely wrong for the 735 circuit. And it has plug in 
> leads where the IC-735 lead placement likely will not match and the 
> original filter is a solder in type.
> 
> Gary K8IZ
> 
> On 8/21/2011 5:45 PM, D C *Mac* Macdonald wrote:
> > Subject line says most all of it. I'm looking for an
> > improvement for SSB selectivity at a reasonable(?) cost.
> >
> > * * * * * * * * * * *
> > * 73 - Mac, K2GKK/5 *
> > * (Since 30 Nov 53) *
> > * Oklahoma City, OK *
> > * USAF, Ret (61-81) *
> > * * * * * * * * * * *
> >
> >
> > 
> > ----
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> 
> 
> -- 
> Gary Fiber K8IZ
> GROL PG-19-6691 with shipboard radar endorsement
> Washington State resident
> 
> ----
> 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/
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