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

[Gary P. Fiber]

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) *
>>> * * * * * * * * * * *
>>>
>>>
>>>
>>> ----
>>> 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/
>>> To support QSL/QTH.net: http://www.qsl.net/donate.html
>>>
>>
>> -- 
>> 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/
>> To support QSL/QTH.net: http://www.qsl.net/donate.html
>   		 	   		
> ----
> 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/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>


-- 
Gary Fiber K8IZ
GROL PG-19-6691 with shipboard radar endorsement
Washington State resident