[Test-Equipment] question

[Carl]

They are not supposed to replace a sharp crystal filter but to augment it by 
reducing the noise bandwidth. Most  ricebox radios are quite noisy after the 
IF filters.

Carl
KM1H


----- Original Message ----- 
From: "Steve" <k0xp at k0xp.com>
To: <test-equipment at mailman.qth.net>
Sent: Saturday, December 12, 2009 1:54 PM
Subject: Re: [Test-Equipment] question


> At 12:11 PM 12/12/2009, you wrote:
>>The K-H filters are certainly usable in the audio. They can be make a good
>>sound system sound like a telephone in bandpass mode and a bunch of other
>>things. They could likely filter out an annoying tone as a notch filter. I
>>don't remember how good the noise floor is, but it's likely pretty good.
>>
>>In the lab, they are useful for cleaning up signals. Most are high
>>pass/low pass/band pass/band reject.(Not all at the same time)
>>
>>Note, My comments refer to engineering based audio, NOT audiophoolery.
>
> I used to have one of these years ago and was very disappointed to
> find the skirts were nowhere near sharp enough for use as a
> narrowband CW filter. They work, but mine just wasn't worth the
> effort. The stock Heathkit crystal CW filter was much sharper.
>
> Steve K0XP
>
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