Although my effort to compare my antennas at home was a noble one, it still needed to be pointed out that switching back and forth between my antennas to see where my WSPR spots were being received, wasn’t the most accurate. Propagation, QRM, QRN can all change from one moment to the next. Though I may get a ‘general’ picture of how well my signal was being received, in order to get an accurate A/B picture, a simultaneous transmission needs to occur from both antennas. In addition, all the other parameters must be equal; i.e. feedline, power, environment. I can certainly control some of these items, but the tools I had been using thus far, WSPRlite, QRP Labs U3S, and my radios, do not allow for a simultaneous transmission on two antennas. If you program two of any of these options to transmit at the same transmit rate, there’s no guarantee that they will transmit on the same cycle.
Enter the W6LVP 3 Band 2 Channel WSPR Transmitter…
A big thank you to Larry, W6LVP for offering this device for such comparisons!
In the back, there are 2 female BNC connectors, and a simple LED light & toggle switch on the front that activate the unit & select the band. The unit is powered by a 12v power supply with barrel connector. That’s one downside to using the WSPRlite is the fact that it requires 5 volts to power – not a huge deal since you can generally power it from your cell phone, but I’ve noticed that the 5 volt power requirement has caused folks to use dirty power sources. The unit will run on 20/30/40m, and is preprogrammed with all the necessary info (Callsign, Grid Locator, etc). Transmitting at half a watt – It will transmit automatically from both antenna ports on every other cycle. Larry hasn’t started commercially making this unit yet, and not sure if there are any plans to, but it has certainly solved one problem I was having with A/B comparisons! Thank you Larry.
Hope to put this device to use for the first time testing out the Link Dipole vs Elevated 1/4w vertical. Two antennas that have a permanent home in my arsenal. There’s something particularly appealing to me when it comes to monoband antennas, they may be a pain to deal with for a band hopper, but the performance, bandwidth & simplicity is unrivalled. I always enjoy going portable & putting up full size antennas. Something I rarely have the opportunity to do at home. Honestly, if I could have a monoband antenna up in the air for every band… well you get the idea!
More later on the W6LVP 2 ch. WSPR transmitter!