From: [email protected] <[email protected]>
Sent: Wednesday, May 7, 2025 8:56 AM
To: [email protected]
Subject: FW: [SFDXA] N4IS Carlos' Acoustic CW Speaker/Filter Demonstration - SFDXA Meeting Tonight

From: [email protected] <[email protected]>
Sent: Wednesday, May 7, 2025 8:52 AM
To: 'Bill' <[email protected]>; 'SFDXA Reflector' <[email protected]>; 'SFDXA on groups.io' <[email protected]>
Subject: RE: [SFDXA] N4IS Carlos' Acoustic CW Speaker/Filter Demonstration - SFDXA Meeting Tonight

Thanks Bill

I am planning a very interactive meeting with a live demonstration. Here is my presentation in pdf so you can be prepare for questions.

See you soon

From: [email protected] <[email protected]> On Behalf Of Bill
Sent: Wednesday, May 7, 2025 7:27 AM
To: 'SFDXA Reflector' <[email protected]>; SFDXA on groups.io <[email protected]>
Subject: [SFDXA] N4IS Carlos' Acoustic CW Speaker/Filter Demonstration - SFDXA Meeting Tonight

BTW: Carlos, N4IS has 308(?) confirmed on 160...few in the world have more...he has been a member of SFDXA for about 25+ years. His company manufactured and sold the Waller Flag for years...

Bill W2CQ

On 5/7/2025 7:10 AM, Bill wrote:

I hope everyone is able to see Carlos N4IS, presentation of an experimental acoustic CW Filter he calls the 3-S.....at the SFDXA Meeting tonight.

I have been fortunate to have been using a prototype for a couple of months now. It is not anything like any filter you've seen before visually or mechanically. Here is a note I sent to Carlos a short while ago regarding an experience I had using it.

"Carlos I just had to tell you...the TX9A today was just a bit too weak to copy on 24.894. But with the 3-S online I was able to hear my call and work him...then an hour later he's on 18074. Once again way too weak...I called him and he came back to someone... I just could not make out the letters let alone the callsign...then I turned the 3-S on, I tuned it, and I heard my call, it was me he was calling!...I quickly sent my report and got the "TU". So in the log on both bands thanks to the 3-S."

I planned on being there tonight, but something unexpected came up yesterday last minute, and I cannot attend. I wanted to relay this quick story to attest to Carlo's remarkable years of research and findings.

AGAIN: It is not anything like any filter you've seen before visually or mechanically.

Attend The Meeting or at least the ZOOM for this presentation

Bill W2CQ