[TowerTalk] Arrival Angle Application

[David Gilbert]

Hi, Steve.

Yes, you need two antennas ... one for each receiver.  And the two 
antennas need to be a configuration that can geometrically capture the 
arrival angle, and they need to be balanced with respect to ground.  
Otherwise the ground effects will be different for each antenna and skew 
the phase measurement.

I'm confused by your second question, though.  The only purpose of the 
entire video was to explain how to use the audio output of the K to 
measure and plot the elevation angle of an incoming signal.  I must have 
done a poor job of that.

73,
Dave   AB7E



On 4/10/2026 11:26 AM, Steve Jones wrote:
> Dave,
> Questions:
> Do you need a separate antenna on each of the phase-locked receivers?
> My K3 can do diversity reception with two antennas.  Is there a way to use the K3's audio to measure the arrival angle?
> 73,
> Steve
> N6SJ
>
>
>
> -----Original Message-----
> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of David Gilbert via TowerTalk
> Sent: Friday, April 10, 2026 12:08 AM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Arrival Angle Application
>
>
> Not too long ago I mentioned that I was working on a application that would hopefully measure and display the arrival angle of an RF signal by feeding the audio from two phase locked receivers into the sound card of a computer and doing the processing on a browser web page.  The application is now functional and I have created a YouTube video describing what I tried to do, how the application works, and to what degree I was successful.  At 50 minutes it's pretty long so if you decide to watch it you might want to click on the YouTube settings icon at the lower right to speed it up.  My production skills are limited so please take that into account.
>
> The YouTube video is here:
>
> https://youtu.be/MxRaYSRMPE4
>
> The actual application is here:
>
> http://www.ab7e.com/ArrivalAngle.html
>
> You can run the app directly from my web page but you can also just download it (right-click, save page as .html) and run it locally on your own computer.  It's totally free and comes with no guarantees of literally anything.
>
> I'd appreciate any comments or suggestions, and I'll try to answer questions.
>
> 73,
> Dave   AB7E
>
> p.s.  The application was written by OpenAI's Codex coding agent.  I created the layout and the prompts that specified how it should work, and I did a lot of refining, but I didn't write a single byte of the actual code.  We're in a new era of custom software for almost any use no matter how limited the audience may be for it.
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>