thanks Jay, lot of good information coming my way--will make a "book"of
all of this and then make my move
73 john
On 7/23/2012 01:07, Jay WS7I wrote:
> Having both owned and used TS-850's for a long time in the past. A
> stock kenwood 250 Hz 455 IF will work just fine. Used them this way at
> W5KFT for many many years. Never operated any 250 Hz filter that didn't
> work fine that came from Icom (751, 761, 765) Kenwood 930, 850. Yaesu
> FT-1000D. No doubt inrad's might be better.
>
> However, if you are using sound card RTTY then wider might actually be
> better. But I continue to use hardware modems along with sound cards in
> combo. I have used the cocoaModem and 2.0 Khz filters, but Chen writes
> much better software than what most windows folks are using.
>
> Jay WS7I
>
> On 7/22/2012 4:52 PM, Joe Subich, W4TV wrote:
>> John,
>>
>>> I can only buy one filter, wanting the most filtering for blood and
>>> guts 160 cw tests, but open enough to allow for fsk operation.
>> When you say FSK operation that fairly clearly puts a "400 Hz" lower
>> limit on the bandwidth and leaves you with two choices the 8830 KHz
>> (1st IF) filter or the 455 KHz (2nd IF) filter.
>>
>> The 1st IF filter will provide a bit better RX IMD performance by
>> getting the "narrow" filter earlier in the IF chain but the 2nd IF
>> filter will provide slightly sharper skirts because of its lower
>> frequency. You can see the filter curves at www.inrad.net.
>>
>> The 1st IF Filter is slightly less expansive than the 2nd. If it
>> were me, I'd flip a coin and get one now and pick up the second one
>> when conditions/finances allow. Ultimately you will want the pair.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
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