Re: Hi-Per-mite CW filter


Am I the only one that finds narrow filters unpleasant to listen to? Whether they're implemented digitally, mechanically,  with crystals, at the IF, or in the audio chain, narrow filters really are hard for me to listen to for extended periods of time.

They're great during the CQWWDX contest at night on 40M (the ultimate filter battleground and dynamic range test) but I turn them off as soon as I can otherwise.    I don't understand the physics of the objectionable "whoosh" they generate but...

John K5MO

On Tue, Dec 22, 2020 at 7:26 PM Timothy East <Timothyeast@...> wrote:
Thanks Johnny. I’ve not done enough CW to think heavily about a filter. 

I like the idea though and also the SSB filter sounds great. 



Ps- hope to see you and the wife at some meetings. We are zooming now. 

On Dec 22, 2020, at 17:39, Johnny AC0BQ <jomatlock@...> wrote:

Hello Tim
It’s a narrow audio filter for CW.
I think it narrows down to 200 Hz?
It will work with any radio since it’s filter the audio output.

We have one that is wider for SSB, but I’m not finished kitting these yet.
Happy Holidays Tim
Johnny ACØBQ 

On Tue, Dec 22, 2020 at 4:35 PM Timothy East <Timothyeast@...> wrote:
Johnny, forgive my ignorance but what does this filter do?


On Dec 22, 2020, at 16:20, Johnny AC0BQ <jomatlock@...> wrote:

Ge group
After a long delay which I apologize for, the Hiper Mite CW filter is back on the shelf.

Here is the link for the order page.

Thanks, 72
Johnny ACØBQ 
Check out the 4SQRP website at

Check out the 4SQRP website at

Join to automatically receive all group messages.