FlexRadio Antenna Analyzer: $20

K9SO

I haven't had many responses to the other projects I've posted here over the past few days so I'll try one last one before I move on.

This uses the Flex API to measure and plot SWR across any band from 160-6m. I'm calculating SWR from the actual FWD and REV dBm readings from the radio rather than count on the radio's SWR calculations which aren't well documented.

This connects to your WIFI network and graphs SWR across any band. Using an internal web server, results may be viewed on any browser on the same LAN.

You may scan with or without CW ID, but please do so on your last scan to stay legal. Tests pulses are only 1 second long so interference will be minimal. You may use the default frequencies or enter your own.

The only hardware needed is an Arduino Nano ESP32 available on Amazon for $20.

The device can save any scan as a reference and will clearly display any changes that may appear over time. You can easily detect changes over time.

I'll post the code on K9SO.COM in a few days, but only if there are interested parties that respond to this post. If not, as I said, I'll just move on and stop bothering everyone with this nonsense

Pat KØPC

This sounds like a very useful tool.

73, Pat K0PC

Dewey WØYWW

I'm very interested in using this tool,
Thanks

serialcoder

Got ESP32 waiting for this. 73 Thanks

KP4IP

Great project! Thanks for sharing it. It would also be great to see it running in a Raspberry Pi. 

K9SO

Please consider yourselves BETA testers as this has not been widely tested yet. This version requires an Arduino Nano ESP32 ($20 on Amazon … don't buy the clones). If there is enough interest and support, I'll port this SW to Raspberry PI.

Imagine placing this tiny box anywhere in your home and have it monitor your antennas without having any direct connections to them itself! Monitor using any web browser on your network. Works with Flex 6000 and 8000 radios discovering them automatically. It saves scans in non-volatile memory indefinitely. Tune antennas and see exactly what the radio sees across every band using your phone. Don't forget to use the ID function on your last scan to stay legal.

I have posted the source code and installation instructions at K9SO.COM under the "Projects" tab.

Please post issues, questions, comments, and suggestions here or send directly to my QRZ email address. I have released the code under a broad MIT license (free to use and distribute with minor provisions).

The unit powers up from a USB-C wall wart (no computer needed) and creates a WIFI SSID for setup. It will discover all active Flex Radios on the same LAN.

Tim K9WX

This does look useful.

I have, for years, used the K9DUR SWRplotter6k to measure antenna SWR and make adjustments as necessary, and it has worked very well for me and my 6600. However, Ray became Silent Key last December so his software is frozen in time. His last version dates to 2019 and I don't know how or if it works with the 8000 series radios or the Aurora. We need a replacement application that, if possible, functions across the entire Flex product line, and that is being actively maintained. (I have a copy of the installation exe for SWRplotter6k 3.2.1 and PDF manual if anyone is interested. Email me directly: TimK9WX at gmail dot com.)

Here is a screenshot of the K9DUR user interface. I have a multiband dipole and a multiband vertical. The red plot is the dipole and the green plot is the vertical. My most common use: run plot #1on the vertical for 80m, make an adjustment to the 80m coil, then run plot 2 to compare the two plots. Then plot 3, plot 4 etc. if additional adjustments need to be made. The vertical has a 3:1 SWR of about 100 kHz so I need to retune as I go back and forth between a CW contest and an SSB contest.

Here is the lone SWRplotter6k setup screen. It is closed when using the app.

I have not tested the Fred's Scanner so my comments below reflect only my observations from what was posted here.

Per the manual, Ray's SWR numbers are derived from the radio's SWR calculations. If these are suspect, Fred's app may be an improvement. Although for my primary purpose of tuning my antennas, Ray's app has performed well and his SWR numbers appear to correlate with my uncalibrated Daiwa CN-901 meter.

Adding CW ID is a plus.

The ability to stand at the antenna, make an adjustment, and then run a new plot to see if I hit the 80m sweet spot is a nice feature. I have never tried that with Ray's software. The tablet PC I would use for that has an ARM processor; hopefully that would not be a limiting feature for Fred's software.

Ray's user interface seems more compact and intuitive to me, although, again, I have not used Fred's product.

Ray's app does NOT require any external hardware but works entirely in software. Fred's app requires that $20 Arduino. The need for hardware will be a barrier to entry for many users, although I would acknowledge that the barrier is not particularly high. However, it is high enough that I have not tested Fred's app. I mostly likely would have tried Fred's app before making this post if the app could do what it does entirely in software. Best I could say right now is that "I hope to try it some day" but that someday is a bit farther off than it would be if everything could be done in software. I think I can safely say that Fred's app would see much higher adoption rates if it was software only.

Bottom line, Fred's experimentation is a big plus for the Flex Community. I hope it receives a positive reaction and further development.

Tim K9WX

K9SO

Thanks for your comments Tim.

I didn't mean to imply the Flex SWR calculations were in error, simply undocumented and since available, I'd rather go to the source data.

The whole idea here was to do this without a computer involved. Results are displayed on any Internet browser from the internal web server so your choice of tablet or PC or MAC is irrelevant. Nothing to load on your viewing device. No software, no apps. Just a one-time load of Nano firmware. This also works with the standard API commands so there's no reason it wouldn't work with Aurora, although not tested. I did test on my 6600, 6400, 8400, and 8600 radios.

This is extremely easy to set up and there really is nothing to build. Plug, load, and play. When done, all you need is a wall wart for power and put it anywhere in the house within WIFI range. Other than the $20, it's free. I posted the source code at K9SO.COM. Anyone can make adjustments these days so as an open source project, there's no fear of it becoming obsolete.

Yes, CW ID is a plus. You are transmitting brief pulses after all even if at low power.

73,

Fred

K9SO

Pat KØPC

About 20 minutes from picking up the Nano ESP32 that had been delivered to the front door to running SWR scans. Great job Fred. Thanks so much for developing this.

73, Pat KØPC

Pat KØPC

I am using this tool with an Aurora and the power settings need to be changed.

The power setting is actually a percentage of full power. For the 6000 & 8000 series radios this tracks with actual output power. However in the Aurora a power setting of 10 gives 50 watts.

I went through the code and changed assignments to scanPower from 10 to 2, including the BandConfig definitions. Some of these changes are just cosmetic so the power listed on the SWR graph is correct.

I think it is possible to query the radio for the model and adjust the scanPower levels before running a scan but I haven't done anything with that yet.

73, Pat KØPC

K9SO

Thanks a lot for the feedback Pat. I didn't consider the Aurora. Yes, I should be able to scan for the Aurora and reset the power levels. I'll post the revision to K9SO.COM later today.

You might send me the code snippets you changed to wa9mvz AT yahoo DOT com

Any other observations? Changes at this point are easy to make. Post some results if you can. That would be interesting.

Fred

K9SO

K9SO

Pat, I have made the following changes. I also had to consider the 200w limit for 6m on the Aurora. The display should now show the actual output power:

Revised code is posted at https://k9so.com/k9sos-flexradio-swr-monitor/ I have only tested this on my 6600 so far.

I am unable to verify this on an Aurora ….yet :-) . Please test when you can and let me know. The update will retain your WIFI and callsign settings.

Flex Antenna Monitor v4.3.4 — Changes from v4.2

• Added automatic Aurora support.
  • The software now detects when the selected radio is an Aurora.
  • Aurora TUNE power is percentage-based rather than watt-based, so scan power is automatically adjusted.
  • On Aurora HF bands, the monitor uses 2%, approximately 10 W.
  • On Aurora 6 meters, it uses 5%, approximately 10 W.
  • FLEX-6000 and FLEX-8000 series power settings are unchanged.
• 60-meter scanning is disabled on Aurora.
  • The Aurora cannot presently produce the intended low-power 60-meter test level using the available integer percentage setting.
  • The 60-meter selection is therefore hidden when an Aurora is selected, and the software also blocks a direct 60-meter scan request.
  • FLEX-6000/8000 radios continue to scan 60 meters at 1 W.
• Improved FlexRadio connection handling.
  • Scan controls remain available even if the previous Flex connection has been lost.
  • When a scan is requested, the monitor automatically attempts to rediscover and reconnect to the previously selected FlexRadio before beginning the scan.
• Added firmware revision display.
  • The running software revision is now shown on the main monitor webpage.
  • It is also displayed on the Wi-Fi setup page.
  • Current revision: v4.3.4.
• Added first-time installation instructions inside the .ino file.
  • Arduino IDE setup
  • Arduino Nano ESP32 board-package installation
  • Board and COM-port selection
  • Firmware upload
  • FLEX-SWR-SETUP Wi-Fi configuration
  • LAN FlexRadio discovery
  • Saved-setting behavior
  • RF safety notes
• Added the MIT License to the distributed source code.
• Existing saved configuration is retained during a normal firmware upload, including Wi-Fi credentials, selected FlexRadio serial number, CW-ID callsign, and saved SWR reference data.

v4.2 remains available for historical value only

Pat KØPC

The new version worked well Fred. It recognized the radio as Aurora without intervention by me. The SWR scan matched my saved reference.

Thanks for the quick update to handle the Aurora.

73, Pat KØPC

VA7BNB_Brent

I will be trying it for sure!

73,
Brent, VA7RV
Flex 6600