Topband: High pass Filters

[Jim Brown]

On Mon, 22 Nov 2004 15:07:17 -0500, Joseph Dube wrote:

>I was wondering if anyone on the reflector had any information a source 
>of highpass filters that could be placed in line with a transciever?  

ICE (in Indianapolis) makes decent high pass filters with a cutoff just below 1.8 
MHz. I have two of them, one of which is in line with my rig all the time. It works 
quite well. I've also measured it using lab quality test gear, and it meets its specs 
quite nicely.  Cost is about $40. Google to find them.  The broadband trash on 160 
dropped a few dB when I inserted it. 

HOWEVER:  Even the best high pass filter won't help if something outside your 
shack rectifies and/or mixes one or more broadcast stations to produce intermod 
products on the ham bands. I have that problem here in Chicago -- it comes and 
goes, almost minute by minute. This morning, I had a big signal on 1830 kHz that 
was a beat between two or more local stations. PITA, nothing you can do about it, 
short of spending a lot of time in the car DF'ing it. And even when you find it, you 
need to get someone to fix it. 


Jim Brown  K9YC