Towertalk
[Top] [All Lists]

Re: [TowerTalk] Are All Low-Pass Filters Alike? -

To: David Thompson <thompson@mindspring.com>
Subject: Re: [TowerTalk] Are All Low-Pass Filters Alike? -
From: Don Havlicek <n8de@thepoint.net>
Reply-to: n8de@thepoint.net
Date: Tue, 16 Aug 2005 16:10:22 -0400
List-post: <mailto:towertalk@contesting.com>
Why don't hams place the LP filter between the Xcvr and the Amp?  That 
way, the amount of harmonics reaching the Amp will be minimized, 
rendering their output levels relatively the same, if not lower, than if 
the LP filter was AFTER the Amp.
BTW:  this is what I have done since the 50's.  Never blew up a LP 
filter yet!
Don
N8DE

David Thompson wrote:
> I have a Drake TV-3300-LP that went south while operating 40 meters with my
> 8877 AMP running 1400 watts out.  Reading the filter its 1000 W Max which I
> assume is input not output.  The coil in the filter melted at one end and
> now rattles around inside the filter.
> 
> I also remember a B&W 1KW LP filter that arced over inside back in the late
> 60'S.  I had been using it with a single 4-400A amp at about 800 to 1000W
> pep
> and the first transmission with a then new NCL-2000
> amp cooked it.  Turns out they used this black plastic
> as an insulator.  I doubled the plastic and it still works
> fine with my 500 watt spare amp.
> 
> Marshall Emm at Morse-X/Milestone Technologies bought AMECO two years ago
> and might be able to
> answer questions on the AMECO filter.  HE has a web page for MOrse-X.  I
> suspect its of the same design as the B&W and the Drake and designed for
> the old KW input limit.
> 
> I do agree with K1TTT that they are probably not needed much today but they
> sure make you feel more comfortable especially on 15, 12, and 10.
> 
> Dave K4JRB
> 
> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any 
> questions and ask for Sherman, W2FLA.
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
> 


_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>