[Elecraft] Broadcast band interference

[Jim Brown]

On 1/14/2013 11:05 AM, Al Lorona wrote:
> There are at least two other ways of knocking down interference from nearby AM
> broadcast stations. Each requires the choice of a particular type of antenna.

The BEST way to kill AM broadcast interference coupled via the antenna 
is with a high pass filter.  This concept is far from new -- it's been 
around since the 1920s. When I lived in Chicago, I used the ICE model 
BCB, which is pretty decent. It's rated for 100W. When the ICE 
owner/engineer died a few years ago, the company was taken over by one 
of the employees under a different name.

WX0B (Array Solutions) was a distributor for ICE, and is selling AM 
broadcast filters built by W3NQN.   One model is designed for receive 
only, so would be used at the RX antenna patch point with a K3. It is a 
VERY sophisticated filter, designed for VERY sharp cutoff so it can 
eliminate stations at the very top of the AM band just below 160M. It 
sells for $225. Another is rated for 150W, with a less sharp cutoff (but 
still a VERY good filter), and sells for $189.  W3NQN filters are pretty 
much the Rolls Royce of filters.

Array Solutions also builds their own RX only filter for $56.  The 
cutoff is not nearly as sharp nor as deep as the W3NQN filters, but 
would likely be sufficient if your interference is below about 1300 kHz.

http://www.arraysolutions.com/Products/BCB%20RF%20Filters.htm

73, Jim K9YC