[hpsdr] Possible added feature request

[Laurence Barker]

Kjell and I are working on this one. It uses a simple VSWR bridge and relay switched capacitors and inductors. It will be integrated into Thetis, so that it can store tuning solutions for each of 3 switched antennas. 

https://github.com/laurencebarker/Aries-ATU

This doesn't follow the feature request: instead it measures VSWR, and selects L and C values to minimise VSWR using a tuning algorithm. It is largely working. We are "fine tuning" the VSWR bridge (we already have directivity better than 20dB on all bands 1.8 to 50MHz) and need to "fine tune" the inductor and capacitor set. 




Laurence Barker G8NJJ
laurence at nicklebyhouse.co.uk

-----Original Message-----
From: Hpsdr <hpsdr-bounces at lists.openhpsdr.org> On Behalf Of Dick Faust
Sent: 04 November 2020 18:52
To: hpsdr at lists.openhpsdr.org
Subject: Re: [hpsdr] Possible added feature request

***** High Performance Software Defined Radio Discussion List *****

Another possible example, with software and other design files:

https://github.com/Dfinitski/N7DDC-ATU-100-mini-and-extended-boards

Uses a simple coupler for SWR with relay switching for capacitors and inductors.

Dick K9IVB

On 11/3/2020 8:31 PM, Scott Traurig wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
>
>
>
> There are plenty of examples of how to do this. Building the requisite 
> coupler is not difficult. You can buy them from Xtronic.
>
> Here's a more relevant example: 
> https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1191&co
> ntext=eesp
>
> Incorporating something like a NanoVNA into this design, and changing 
> the software to calculate the required L and C directly instead of 
> iteratively should be possible.
>
> This could also be accomplished using a link coupled topology if you 
> prefer.
>
> 73,
>
> Scott/w-u-2-o
>
> On Tue, Nov 3, 2020 at 2:38 PM <radio at netins.net 
> <mailto:radio at netins.net>> wrote:
>
>
>     Using SWR is done when tuning L networks, but would like to try
>     adding stepper motors to a Johnson Viking Matchbox so I can use it.
>
>     I can't seem to come up with a method to tune for minimum SWR.  I
>     suppose one would adjust first the tuning and step the loading one
>     way or the other and use the low SWR position to hold for the next
>     iteration.  Then repeat that process over and over.
>
>     I have been told it is quite difficult to make a directional
>     coupler that works well over the 160 - 6m range, but a calibration
>     file could be made at the antenna system feed point (input side of
>     Matchbox) that might get a close enough calibration to use for
>     tuning.
>
>     John,  W0GNhpsdr-openhpsdr.org/
>     <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/>
>
>
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