Topband: BCB interference ?
Chuck Hutton
charlesh3 at msn.com
Mon Sep 22 15:22:05 EDT 2014
Their description (to me at least) indicates an elliptic filter with a stopband peak of -40 dB at 1 MHZ and ranging to infinity (in theory) elsewhere in the stopband. In other words, 40 dB is the maximum for the discrimination factor.
"Indicates" is a word I feel is necessary as their filter really is poorly described. They should have said what filter type and order are used and used standard nomenclature for filter parameters. And there's no mention of passband ripple.
Chuck
> Date: Mon, 22 Sep 2014 11:21:29 -0700
> From: jim at audiosystemsgroup.com
> To: topband at contesting.com
> Subject: Re: Topband: BCB interference ?
>
> On Mon,9/22/2014 6:50 AM, Ed Stallman wrote:
> > Has anyone used this High Pass Filter ?
> > http://www.dunestar.com/store/160-Meter-Highpass-Filter-pid-8.html
>
> The spec for this filter is ambiguous. Is the -40dB at all frequencies
> below 1.6 MHz, or at 1 MHz? BIG difference. OTOH, the Dunestar filters
> are decent for the price.
> 73, Jim K9YC
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