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

[D C *Mac* Macdonald]

Inrad shows that all six of those are applicable to the IC-735.

 
Is Inrad in error?

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

 

 

> Date: Sun, 21 Aug 2011 20:01:16 -0700
> From: gfiber at comcast.net
> To: icom at mailman.qth.net
> Subject: Re: [ICOM] Wanted: Narrower (than stock) SSB filter for IC-735
> 
> The 455 Khz filters will not work in the IC-735 Though the 455 Khz 
> filters generally have a better overall shape factor. I like to think 
> that's because the crystals are bigger and easier to grind than the 9 
> MHz crystals are.
> 
> Gary K8IZ
> 
> 
> On 8/21/2011 6:56 PM, D C *Mac* Macdonald wrote:
> > 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) *
> >>> * * * * * * * * * * *