The Dummyloads

Where ham brains come to fry

Where ham brains come to fry

Diagnostic Tools

Rig Expert AA-230 Zoom

For sometime I have had a MFJ-259B that I had purchased from an SK estate.  I have treasured the device for a number of reasons.  I knew what I had paid for the device was helping that ham’s family and I felt like I needed to honor his memory by using the analyzer.  Use it I did!  KB5NJD even helped me mod it so it would give us readings down to 470 kHz and I could tune my 630M antenna.  As my knowledge has improved, I came to find that there are a lot of things this model of antenna analyzer does not do and that made me think about getting a different device.

One:  It doesn’t resolve the sign of X.  i.e. is my load inductive or capacitive?  W2AEW has a great video on how you can actually resolve the sign of X using a smith chart using an MFJ 259B style analyzer.

Two:  The oscillator in the machine is not particularly stable in my opinion.  i.e. what freq I was measuring was in doubt by up to 20hz.  This isn’t a deal killer for measuring impedance in the field, but is frustrating in a lab environment.

Three:  The freq. knob is too sensitive in my opinion.  I suppose it makes sense given the tuning range within each band the analyzer covers, but I wanted a little more precision.

Four:  All it provides is Freq (approximate as noted above), SWR, R and X (unresolved whether it is positive or negative.)

Again — As a new amateur, it is perfectly adequate as an antenna analyzer.  But I wanted something a bit more capable.  As it turns out a friend has an AA-600.  He was showing me his conventional transformers and how he could measure the frequency response with the AA-600.  Not only will it define the sign of X, this thing draws a Smith Chart.  It will auto sweep over the entire spectrum of the oscillator enabled on your machine.  You can do live measurements where it will show you the rectangular format of impedance and the vector form of impedance.  This is a genuine scientific instrument.

Now the question is what frequencies should I cover?  I genuinely only have an interest in HF, BUT satellite contacts are interesting. . . and I’ve recently started doing some VHF fox hunts with a local club.  At some point I’d really like to build some kind of 2M yagi.  If I was doing satellite contacts, it would be ideal to have a 440 beam as well, but the cost differential and the likely hood I would ACTUALLY build such a thing. . . I’ll probably just by a satellite antenna, it’ll be close enough.  🙂

If I decide I really want to experiment at 440 MHz I can always up grade later.

 

KF5RY

WSPRlite. What it is and how to use it. (with the ZM-2 Tuner)

This episode we’re talking about the WSPRlite flexi.

https://www.sotabeams.co.uk/wsprlite-antenna-tester/

Now this is a cool little device made by the folks over at SotaBeams in the UK that lets you test your antenna’s actual transmit propagation in real time. It uses the WSPR protocol (Weak Signal Propagation Reporter) originally developed by Joe Taylor K1JT. (Quite an interesting guy, you should look him up.) Now WSPR is open source and still actively worked on. Please find relevant links below.

https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software)

http://physics.princeton.edu/pulsar/K1JT/wspr.html

http://wsprnet.org/

I’m not going to tell you how to install the support software, as that’s all very well documented when you buy the unit. The point of this episode is just to go over what it does. So, let’s go straight into the setup app where you can update the firmware and set up the device for operation.

After you plug the WSPRlite in to the computer, pick the correct COM port and click CONNECT.

Every so often, I click Update firmware, to make sure it’s current.

Then, enter your callsign and first 4 digits of your QTH locator. Currently WSPRnet only uses the first 4.

Honestly, I’m not sure what the CW callsign checkbox is for, so I ignore it. If you know, please post in the comments below and share your knowledge.

Choose the band you wish to test. Once you pick a band, it will pick a random frequency in the WSPR accepted range.

The flexi version of the WSPRlite has lowpass filters for 20 & 30 meter bands built in. You may need to get some external lowpass filters for any other band you wish to test, depending upon where you are operating from. The WSPRlite will work without them, but you may end up operating out of bounds depending upon your location. Something to keep in mind. I don’t have any other lowpass filters yet, but they’re on the way if I need them.

Then, pick your power output. I’ve just been leaving it at the default 200 mW which, when using the WSPR protocol is equivalent to 1000 watts of SSB. I’m not using an external amplifier, so I leave the Reported power at it’s default.

They suggest leaving the Repeat rate at 30%, so that you’re not hogging the frequency every minute. I’ve also left the Max runtime at it’s default of 3 days.

At the bottom is a very important link. This will send you to your own, personal DXplorer.net report page for your specific device. We’ll get to that later, for now, go ahead and click Open in browser, then, when it opens, bookmark that link. I think it will generate a new link per band.

Lastly, go back up and click Save WSPR Settings.

That’s it, you’re done. Unplug the device and let’s get set up to transmit.

I use my radio power supply,…

… and plug it into the SotaBeams Power Conditioner. When I didn’t use this, the power supply generated an ugly buzz in the transmission. So, I bought this conditioner as a kit, and haven’t had an issue since.

Plug it into the WSPRlite

Connect the feed line…

Which goes to my Emtech ZM-2 QRP tuner which I’ve posted a pictorial write-up on the build previously, see that link below.

http://dummyloads.com/emtech-zm-2-tuner-build/

Then attach the antenna to the Tuner.

Wait for 2 seconds past the minute on my atomic clock….

aaaand press the button to start transmission.

On the ZM-2, flip the switch to TUNE and fiddle with the knobs until the light goes out, or as dim as possible. If you turn the knobs to the stops and the light stays bright, try Adding picoFarads and keep trying. I took my time here. At 200 mW, I wasn’t too worried about overheating anything. When done, flip the left switch to Operate which takes the LED out of the circuit and give you the least resistance on the line.

Done, you’re now transmitting. Give it a while to transmit for a few minutes, and then go to the above mentioned DXplorer.net link you got from the setup app.

The DX10 Table shows you a list of your best 10, in range every 2 minutes or so.

The Graph is a visual representation of the data points of all your connections. In every report, you can choose a time frame snapshot.

The Spots map is … well, self explanatory.

The Spots table shows you all your spots, most recent on top.

If you’ve tested on other bands, you can swap over to them here.

And there you have it. This is a very useful bit of kit that lets you see just how well your antenna is working based on it’s configuration and current propagation conditions. For around $80 and it’s diminutive size and weight, I highly recommend it. You get a very accurate, real-time picture of how long your radio’s arms are at that moment. Especially in our current solar minimums, it’s quite handy to test out where you can reach.

If this video was helpful in any way, please, give us a thumbs up. If you have any questions on the WSPRlite flexi, please post them below. I’m no real expert, but I’ll be happy to get back to you with what I know.

Thanks for watching the DummyLoads. See y’all next time.