[Elecraft] Mobile high power

[Jim Brown]

I took delivery of my 2006 Toyota Sequoia SUV in time to make multiple 
trips moving from Chicago to NorCal, carrying stuff like master tapes, 
tech equipment, and other things I didn't want to fight with the moving 
company about their losing it or breaking it. Prior to the first trip, a 
ham friend opened his heated garage to me in a Chicago winter and helped 
me pull power from the battery and mount an antenna mount on the roof 
rack. Using an ohmeter, we found that there was no continuity between 
adjacent screws -- some were insulated by paint, so we had to poke 
around to find one to bond coax shield to the chassis to make it a 
counterpoise.

I ran HamSticks, and found that they worked well enough, and mostly 
worked CW.  I mostly used an IC746 on the seat beside me, and found that 
the antenna tuner was a big help with the narrow resonances of short 
antennas.  That vehicle, which I still own, has bodacious RFI, but in 
the process of moving cross-country, I had no time to think about fixing 
it. I had mostly run one band leaving Chicago, and noticed that the 
ventilating fan sped up when I transmitted. No big deal. But driving 
through the very isolated NV desert the next day, I fired up on 20M, got 
three responses to my CQ, and then noticed that my speed had dropped to 
20 mph -- RFI had gotten into one of the vehicle's computer and put me 
in "limp home" mode. Luckily, I had tools with me -- pulling fuses 
didn't reset the computer, so I had to pull the positive battery lead to 
reset the computer.

This weekend, K6EU and I ran 6M FT8 and MSK144 from that vehicle with a 
K3 to a 6M whip. RF got into everything, which I tamed with a dozen or 
so chokes formed by 2 turns through a #31 clamp-on, multiple chokes in 
series on each cable, including the coax at the antenna. That shouldn't 
be a surprise -- the vehicle chassis is half of the antenna.  The clamps 
didn't help his Apple phone, which locked up in the presence of 100W of 
6M. My Motorola phone had no RFI issues at all, even when we parked at 
county lines and ran a KPA500 from a generator to a 3-el Yagi 6 feet 
from the car. The objective of Tom's operation was to activate two rare 
grids for 6M grid chasers.

73, Jim K9YC

On 5/6/2019 8:31 AM, Wayne Burdick wrote:
> My Prius is so dependent on embedded processors that I take no chances -- I run only 10 W mobile. Yes, it's harder to make contacts, but my car doesn't have E-peleptic seizures.