[CQ-Contest] 6-band W3NQN-design filter unit

[Tod-ID]

Pete, et. al.

This article has been on the web site for some time. As I recall the
translation was fairly straightforward so I would assume one could use the
in-line translators to get at least the essence of it. The capacitors that
they used may not be available in the U.S. The design is based upon the
W3NQN articles in QST and perhaps QEX. That will make the curves
substantially better than the Dunestar or ICE units. 

You can find a copy of the QST articles at
 => http://www.k0to.us/HAM/Articles/articles.htm


One does need to factor in the value of personal time used in building, cost
of parts [when you finally find them] and the relative difference between
those filters and the ICE and Dunestar ones. A 10 dB reduction for the
sub-harmonic and second harmonic may be inconsequential in a particular
situation.

The relay and coax system is similar to that found in the Dunestar 600 unit.

To really knock down the harmonics of a transmitter probably coax stubs will
provide the lowest cost and simplest to construct method. I believe that
commercial [ham radio specific] sources exist that supply the parts,
assemblies and perhaps the entire package for those who do not want to be
involved in the assembly and construction aspects of things.

Top Ten Devices is one source but I think there are other sources as well --
perhaps Array Solutions.



 Tod, K0TO


-----Original Message-----
From: cq-contest-bounces at contesting.com
[mailto:cq-contest-bounces at contesting.com] On Behalf Of Pete Smith
Sent: Tuesday, September 02, 2008 4:25 AM
To: CQ-contest at contesting.com
Subject: [CQ-Contest] 6-band W3NQN-design filter unit

While looking at DH1TW's excellent web site, I followed a link to what 
looks like a very neat implementation of the W3NQN-design bandpass filters 
in a single unit for 6 bands, with relay switching.  This work appears to 
have been done by DL2NBU and DL6RAI.  The link is 
http://www.bavarian-contest-club.de/projects/bandpassfilter/100W-BP.pdf 
.  It would be a real service to the English-speaking contest community if 
someone with the needed language skills could translate this article from 
the German.  It looks as if the performance is miles better than either the 
ICE or Dunestar filters.

Before someone volunteers the info, I know that Array Solutions markets a 
similar solution, but the cost is comparatively prohibitive.

73, Pete N4ZR

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