Outstanding Kim!
This is exactly what the world of Yaekencom users don't realize they're
missing.
They accept 'intra-transmitter' interference at multi-transmitter events as
a given.
(I think I just made up a word.)
The acid test is when operating 4U1VIC in Vienna.
I've run CQWW DX CW from there several times.
At that site, ALL antennas from all stations have to be located on top of
the roof of the main building. You are not allowed to string wires to other
places, other buildings, etc. Of course that building is about 400 ft. tall
which helps the signal a lot.
(picture:
http://en.wikipedia.org/wiki/United_Nations_Office_at_Vienna )
In this case, you can't obtain the kind of separation recommended by K3LR
and W3LPL in their course on antennas for multi-multi contesting, which they
teach at Contest University in Dayton.
I always took along a pair of Omni VI transceivers. Some of the others
brought their flavor of the day Yaekencom. Even without band filters (which
weren't commercially available then), my two Omni's did not disturb each
other when operating on separate bands unless they were on an exact harmonic
frequency. The Yaekencoms were useless. Their owners cried all the way
home. They were in disbelief!
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Kim Elmore
Sent: Friday, May 02, 2014 4:12 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Wide roofing filter for the RX-366?
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@sbcglobal.net>
> To: "Discussion of Ten-Tec Equipment" <tentec@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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