[TenTec] Wide roofing filter for the RX-366?

[Kim Elmore]

Yes, it's easy to conflate roofing filters with the more familiar IF 
filters. They don;t serve the same purpose but can be complimentary. 
Sherwood's presentation is excellent.

In my case, there's a guy about 2 mi away that runs 1.5 kW with a good 
beam at 70 ft. He's strong enough to cause problems when he's on the 
same band and pointed at me. There are several AM BC stations around and 
couple are 50 kW oxyacetylene blowtorches, one at 1000 kHz. Because of 
them,  roofing filters really do help on 160 m.

When I took my Orion II to FD, all the CW ops fell in love with it 
because all the other local FD QRM vanished; it was as if they were all 
alone. Even the phone ops were amazed they they could tune to within a 
few kHz of one of the phone stations and have zero trouble with IMD.

Kim N5OP


On 5/1/2014 8:38 PM, Bob McGraw - K4TAX wrote:
> While roofing filters are indeed nice and serve a really nice 
> function, I truly believe  the lack of understanding as to what they 
> do and how the perform and when they are needed is in short supply.    
> I  found that the "authority" Rob Sherwood has a very nice 
> presentation on his website where he discusses the advantage and 
> importance of roofing filters.
>
> My general take is:  If one intends to operate with 5 to 10 active 
> stations in an area the size of a football field on an event such as 
> Field Day,  then they are absolutely necessary.  Otherwise, if you 
> live in an area 5 to 10 miles from town and the nearest ham does not 
> operate on the same band the same time as you, then they aren't 
> necessary but, certainly nice to have available.
>
> Just remember, the selectivity is developed by the DSP system.
>
> 73
> Bob, K4TAX
>
>
>
>
> ----- Original Message ----- From: "Kim Elmore" 
> <cw_de_n5op at sbcglobal.net>
> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
> Sent: Thursday, May 01, 2014 8:16 PM
> Subject: Re: [TenTec] Wide roofing filter for the RX-366?
>
>
>> While filters are expensive, they can be swapped out without a lot of 
>> trouble. That said, I chose a wide filter of 6 kHz, then the 2.4 kHz 
>> standard filter and finally a 500 Hz filter for the narrowest. In my 
>> environment, I won't have to deal with any strong (next door) signals 
>> in a 500 Hz passband. Whenever I take the rig to, say, FD, only the 
>> main rx is much used and it has the 300 Hz roofing filter, 600 Hz, 
>> 1.0 kHz, 1.8 kHz, 2.4 kHz, 6 kHz and 20 kHz filters.
>>
>> I can't see the point in having a 2.7 kHz, 2.4 kHz, and 500/600 Hz 
>> filters because there's not enough difference in the 2.7 kHz and 2.4. 
>> Perhaps a the standard 2.4 kHz, 1 kHz and 500/600 Hz filter would be 
>> best if you have no interest in AM.
>>
>> Kim N5OP
>>
>>
>> On 4/30/2014 9:15 PM, Carl Gansen wrote:
>>> I am curious about what members of the list are using for their wide
>>> roofing filter
>>> in the RX-366. At this time, with CW as my main interest, I have a 
>>> 600Hz
>>> and a
>>> 300Hz in place in mine.
>>>
>>> I have little to no interest in AM but I do listen in on digital 
>>> modes with
>>> FlDigi.
>>>
>>> Can anybody offer some thoughts on the filter (brand & bandwidth) 
>>> that they
>>> chose
>>> and the reasoning behind that choice?
>>>
>>
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>
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