I purchased an Argo 650HD amphibious 6x6 for surveying that has a Briggs and Stratton Vanguard engine, Model 386447-0144-G1. I use Topcon Hiper Lite Plus GPS equipment that consists of a base and rover that communicate via a 915 MHz spread spectrum radio link:http://i581.photobucket.com/albums/ss252/N1048D/Argo800x600.jpg
The GPS radio link signal is normally usable out to about 1.5 miles in the relatively flat farm country I am working in. I am loosing the GPS radio link at a distance of about 1/2 mile when I rev the engine in the Argo. I regain the GPS radio link when the Argo engine is at idle or, of course, when it is shut off.
The gasoline engine in the Argo has resistor type spark plugs. I am now in the process of deciding what to purchase or build, as far as filters for the charging system, etc.
Any ideas or suggestions on where to start? I have contacted Briggs and Stratton, but have yet to get in touch with anyone that is knowledgeable. Topcon is of little help since this is a very specific case, works fine in my pickup. I am on my own on this one so any help would be very much appreciated. I thought about going to a two-way radio shop and using a spectrum analyzer to gain some insight into the problem.
Now to make this post related in some way to amateur radio...Before I setup my internet remote base, I ran my TS-480 in my pickup while I was surveying. Listening to amateur radio helped pass the time while spending 12+ hours per day in my pickup. During the winter while the farm fields are too soft for my pickup, I will be spending long days in the Argo. I may throw the TS-480 in the Argo and mount a hamstick on the overhead bracket behind the GPS receiver and make a few contacts.