[TowerTalk] Are All Low-Pass Filters Alike?

[David Robbins K1TTT]

The most important question to ask about TVI filters is "Do I have a
transmitter harmonic problem?".  Remember, TVI filters can only stop
harmonics... and they can only stop harmonics that come from BEFORE them in
the coax.  If you have an overload problem, or outside rectification, or
rectification in the receiver antenna, or a receiver preamp overload, or a
stereo system getting overloaded, or any of a dozen or more other problems a
harmonic filter is just a waste of money.  So before asking which one is
best, ask if that is really what you need.


David Robbins K1TTT
e-mail: mailto:k1ttt at arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
 

> -----Original Message-----
> From: towertalk-bounces at contesting.com [mailto:towertalk-
> bounces at contesting.com] On Behalf Of doc
> Sent: Tuesday, August 16, 2005 02:33
> To: towertalk at contesting.com
> Subject: [TowerTalk] Are All Low-Pass Filters Alike?
> 
> Just read the specs for the AMECO low pass filers and wondered
> if it is fair to guess that all 10M filers really handle meaningful
> 10 & 15M garbage and that a 15M filter is not really necessary?
> 
> LOW PASS FILTERS (Cat. #AM-LP-10 AND LP-15)
> Rugged, high-performance rock solid low pass filters, protect against
> unwanted harmonic emissions that cause TVI and other interference
> problems.  Stops all 2nd and 3rd harmonics on 10M, as well as the 3rd
> harmonic of the 15M band.  Both units protect all TV frequencies above
> 52MHz and have very low signal loss up to 30MHz. Model LP-10 handles 1KW
> continuous and LP-15 handles 1.5KW continuous.  The LP-10 uses a 9-pole
> modified Chebychev design and the LP-15 uses a 10-pole Cauer (eliptical)
> design.
> 
> --
> Thanks! & 73, doc kd4e
> 
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