This is the mobile WSPR page. The main WSPR page is here.
Audio intro:
I’m now mobile with WSPR on 10 metres. This started out as an experiment but, as the results have been amazing, I’m using my Zach Tek transmitter to go mobile most days. It’s hard to believe that the aerial on top of my car is transmitting 200 mW to South America, the West Coast of North America, Russia, Europe… I have yet to be heard in Australia, but I’m sure it’s only a matter of time.
When looking for my signal on the WSPRnet online map, remember to type in my mobile callsign, G4NSJ/M. You won’t find me with out the callsign suffix /M. I do transmit my full Maidenhead Locator from the car, IO90TT, so you’ll be able to track me as the squares change.
I’ll be transmitting 200mW on 28.1261MHz, using the 1/4 wave (base loaded) mobile antenna is shown here. It’s a CB antenna cut for 10 metres. My plan is to drive up to the top of the south downs (High Salvington north of Worthing) and check the results there. It’s about 126 metres ASL (430 feet). I’ll be out and about mobile quite often but, even when the car is parked at my QTH, the transmitter will be running.
Midday, mobile:
6/2/25. 1200 hours.
I’ve been heard in The Canary Islands, Romania, Finland, St Petersburg, Iceland, Connecticut, and Moscow. The map below shows stations hearing me at 1200 hours.
9/2/25. 1220 hours:
Heard in Russia, just north of Mongolia.
Late Afternoon, mobile:
6/2/25. 1700 hours.
The map shows South America, west coast America, Canada, Russia, Turkey… Quite amazing for 200mW mobile!
My Zach Tek transmitter:
I’ve installed my Zach Tek transmitter in my car and it works wonders!
SWR and the Zach Tek Desktop Transmitter:
Apparently, the transmitter can withstand infinite SWR. This good news if you are band-hopping or if your antenna isn’t properly matched. However, the radiated power could be down to single digit milliwatts due to reflected power.
Conclusion:
Using the Zach Tek transmitter when mobile has brought amazing results. If you’re looking for me on the WSPRnet online map, remember to type G4NSJ/M. I would appreciate signal reports, if you have time. The WSPRnet online database is extremely useful when I’m mobile as it shows the date and time, the square I’m in, who heard me and their location, my signal report and more. Check out the database.
Here is a screen shot of the database when I went to Amberley Museum. I left home at 08.54 from my square IO90TT. Gaps in the listing are either where I was parked at the museum and turned the TX off or my signal dropped out when mobile. I prefer to look at the database rather than the map as there’s so much more information available.
Here is an excellent web site.
Interpreting WSPR Data for Other Communication Modes.
I’m working on this text so ignore it.
Thanks to those who have sent me the information below.
Manual Maidenhead Locator:
When I’m at my home QTH, I need to transmit the standard message. Callsign, and a 4 digit locator.
This requires one transmission sequence of two minutes duration.
The transmission carries callsign + 4 digit locator + dBm transmit power.
Auto Maidenhead Locator (GPS):
When I’m mobile, I need to transmit my callsign with the suffix /M plus a 6 digit locator.