WSPR Station

The Solar Eclipse QSO Party urges, “Operate a wide-band automated receiver at your station” like a wspr station.  The station has been in staging at home before it gets deployed to the permanent site in Strasburg but not working correctly.  Finally a breakthrough.   Today we figured out a problem.  Now we’re seeing our wspr station being spotted on wsprnet.org, running only 1 watt and feeding a Hustler mobile whip antenna.

Screenshot 2017-07-23 19.54.16

This is the Hustler mobile antenna getting that big 1 watt signal around the country.

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The WSPR station being staged before deployment looks like this.

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The computer is an Intel Compute Stick, on the left side half way up running Windows 10 and WSJT-X version 1.8.  The red box is a West Mountain Radio PlugNPlay Rig Runner to interface to the Yaesu FT-817.  The yellow candy wrapper is shrink wrap around a dc-to-dc converter.  It takes in 12 volts dc and converts it to 5 v dc for the powered usb hub and for the Intel Compute Stick.  Green and blue plugs from the PlugNPlay go into an external usb sound card.  One of the usb dongles is a Yaesu CT-62 CAT interface cable.

Deployment plans include packaging the above apparatus into a fiberglass outdoor enclosure, then adding a solar panel, controller, and batteries.  The permanent antenna will be a Cushcraft AP8A trap vertical picked up at a recent hamfest.  The complete 12 volt station draws 1.3 amps when transmitting (at 1 watt) and draws .6 amps when receiving, including the computer. Can’t use an automatic tuner because wspr changes bands and listens before transmitting.  That means the tuner is still tuned to the previous band instead of the current one.  Must use resonant antennas like trapped vertical.

We’ll turn on band hopping and cover 80 through 10 meter bands.  If we get the ambition we’ll add a 6m vertical stub and cover that band, too.  This project is targeting the August 21, 2017 solar eclipse.  In addition to WSPR we plan to operate the Solar Eclipse QSO Party using weak signal modes JT65, JT9, and FT8 on the main station. We’ll be receiving on 630 meters and transceiving on 160 through 6 meters making as many QSO’s as we can.

First plan went out the window because a trapped vertical needs radials and the weeds  make that impossible.  Plan B is to try a Comet CHA250B because it requires no radials.  It just didn’t get a signal out. Out the window.  Plan C is to receive only at Strasburg and transmit only from home.  Can’t receive from home due to a high noise level.  But at Strasburg  when unchecking all the transmit boxes in wspr it no longer band hops.  Is this a bug?

A solution popped up while reading the manual to try to see why it stopped bandhopping.  There is a “tune” checkbox that sends unmodulated carrier for a few seconds after changing bands.  We just happen to have the ideal tuner — a SGC SG-211.  We’ll try that next.

The SG-211 failed because it needs more than a watt for tuning.  Next we tried a LDG RT-100 and it worked perfectly.

Update, September, 2022 —  Zachtek WSPR Transmitter is discovered and solves the problem.  See QST, September, 2022, ZachTek WSPR Desktop Transmitter, page 44.  “The ZachTek WSPR Desktop Transmitter is a standalone multiband WSPR transmitter that contains its own WSPR firmware, so it does not require an external computer and software to operate.  Although it’s a low-power transmitter, you will be surprised how far you can get with it — even mobile!”.  The transmitter was ordered, arrived a week later, and was installed.      

For an antenna, the Hustler 6BTV that was originally purchased for WSPR in 2017 was called upon. Part of 6BTV installation is carefully tuning each band to the WSPR frequency for that band.

The ZachTek has been in service since early September, 2022 and the results are quite impressive as demonstrated by the late morning screen shot below.

It runs on 5 volts and is very reliable so far. There is one issue, however, and that is rf interaction with the main station. When the main station is transmitting on 40 meters the ZachTek crashes, even with a lot of toroids on the leads. It recovers with a reboot. This issue was solved by installing a relay to turn off the ZachTek whenever the main station is turned on. When the main station is turned off and the ZachTek is turned back on, it reboots automatically and begins transmitting again. All settings are preserved each time and does not require manual intervention. Missing out on WSPR while the main station is running is very frustrating when the main station is running for a long time. An alternate solution is needed.

Commentary. At any given moment in 2022 there are more stations on FT8 than on WSPR or any other beacon network. The shear quantity of stations operating FT8 outnumbers the number of WSPR stations and therefore provides more information. As good as WSPR is, PSKreporter may be better because it shows a broader picture of propagation. Take a look at PSKreporter for the same time and draw your own conclusion. PSKreporter is configured to display the local grid square, all bands, all modes, for the past 15 minutes.

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