[Top] [All Lists]

Re: [Amps] new mobile amps from THP

To: "amps@contesting.com" <amps@contesting.com>
Subject: Re: [Amps] new mobile amps from THP
From: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 11 Jan 2006 09:06:38 -0600
List-post: <mailto:amps@contesting.com>
On Wed, 11 Jan 2006 06:30:40 -0800, Bill Turner wrote:

>I like the idea of HP mobile, but I still hear concerns about RFI to 
>the car's electronics. Has anyone had any experience with this lately?

YES! I just put a 100w HF transceiver in my 2006 Toyota Sequoia and drive 
to CA with it. Power straight from the battery, antenna a Hamstick on the 
luggage rack, shield of coax bonded to a big bolt holding the luggage rack 
to the roof. Antenna works great, and I had lots of fun on 17m CW and SSB. 
Had to turn off the car's climate control when I worked CW, because it was 
speeding up when I keyed the radio. 

BUT -- the Toyota Sequoia is an EMC nightmare -- when I fired up on 20 SSB 
and called a 15 sec CQ, the Toyota's main computer crashed, leaving me dead 
in the water in the middle of the Nevada desert! No fun. I managed to get 
rolling by pulling the power lead off the battery to reset the computer. 

Prior to installing the rig, Ron, K9IKZ and I poked around with an ohmeter 
to see what was bonded to what so that we could find a decent connection to 
the body for the antenna and understand how the vehicle was shielded. What 
we learned is a disgrace -- two bolts a few inches from each other holding 
the luggage rack to the body read 60 ohms between them. Bolts at opposite 
ends of the luggage rack and on opposite sides are 3-6 ohms apart. A copper 
strap supposedly tying the battery negative terminal to the body reads >10 
ohms to those bolts and to the body near the bond! In other words, almost 
nothing is bonded together, all the bolts and washers have paint between 
them and the body. 

Because I'm in the middle of moving from Chicago to CA over the next few 
months, I won't have time to dig into this and clean it up. I will, of 
course, add ferrite chokes to power leads for the ham gear and to what 
senstive electronics I can find. And I'll bond everything I can find, 
including body parts, tailpipe, hinges, etc. But what a mess! This is 
absolutely SHAMEFUL!

Jim Brown K9YC

Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>