Rick, I have an IC706MKIIG radio.  A Powerwerx Timer/Switch unit will allow me to program it for up to 12 hours, so that should work nicely for my needs.  When I'm operating stationary, it's only for 30-45 min before I restart the engine.  Since I'm only operating on VHF and sometimes UHF, the maximum power my radio provides is 50W, which draws significantly less than the 20A needed for full power (100W).

I can see the advantages of connecting to the battery, and I'll feel much better knowing I can't accidently leave the radio on when I'm not there.

Bruce, KK4IKO

I do believe the laws we have should be enforced, absolutely.  However, we might take a cue from traffic law enforcement in West Germany.  Yes, it is against the law to give another driver the bird; and fines are levied based on the offender's ability to pay.  You make more money, you pay more.  Hitting the pocketbook in a noticeable manner is a great attention getter.

Bruce, KK4IKO

K0BG,

Just checked out your website, and I must say you have a lot going on there.  It's guys like me who really appreciate good solid info made available by good folks like you.

Anyway, with your help, my dilemma has been solved.  I'm going to order one of those Timer/Switch units from Powerwerx, and run out to the battery.

One question, though...does the radio require a separate ground connection to the vehicle for mobile use, in addition to the power ground?  It doesn't show one in the radio manual.  My meter indicates that all points which should be at ground potential, are grounded to the vehicle chassis and sheet metal.

Bruce, KK4IKO

I am using a drilled NMO mount in the center of the roof.

K0BG, I understand what you are saying.  How would you suggest connect directly to the battery, so that I still have peace of mind about my radio not being on when the key is off?  Like I said, my CRS is kicking in so I'm tending to go with more foolproof stuff.  Should I install a relay, controlled by the ACC circuit, in the line, or would I need an electronic switching circuit of some sort to avoid interaction with the vehicle's electronics?  In the 6 months since installation, I have detected no issues. 

My mobile unit's (2000 Jeep Cherokee Sport) battery monitoring system is the old fashioned kind...battery dies, no workee.  No advance warning or protection like on my new car. 

Bruce, KK4IKO

Hi,

I've read some comments about connecting the power source for a mobile rig directly to the car battery, using very large conductors (#8@40A, or #6@50A).  My radio is rated for 20 amps, #12 wire, so I removed the cigarette lighter and connected #12 directly to its wires.  My cigarette lighter is fed by a 20 or 25 amp relay, through a 25 amp fuse.  The ignition switch has to be in the ACC position, or the engine running to hot up the radio, which means I can't accidentally leave the radio on when I remove the key.  I have CRS these days, and that sort of stuff happens more and more. 

I'm only setup to use the radio on VHF, and UHF in my vehicle, for which my radio restricts the power to 50 watts or less.  I don't see the  advantage of going to larger conductors and connecting directly to the battery in this case. I am a retired industrial electrician, so a detailed technical answer will be understood.

My rig for HF is in the house.

Bruce, KK4IKO

Based on my experience with a large CB antenna mounted on the roof of a previous home, I found a simple way to add to its life.  If the joints and screws are carefully wrapped with Scotch 33 and sprayed with a couple coats of clear acrylic finish prior to installation, the integrity of these points will be maintained for many years.  I know that to do this is a bit of a pain, but the results are worth it.  The newer liquid tapes might also work, and the acrylic protects from UV.  When I took that antenna down after about 10 years, it appeared to be as sound as when installed, and it was used when I put it up.

As a lifelong Electrician, I've learned that you do NOT stretch the last complete turn of electrical tape, but CUT it off and press it down it smoothly over the stretched wraps.  Stretching that last turn is what contributes most to the tape unravelling.  Bite the bullet and use the Scotch 33 or 88, not the jap wrap!

KB3VIS...

What area of North Carolina are you in?  I'm in the mountains near Asheville, and I too am setting up a new HF station, struggling with what it's going to take for a decent antenna down in this crack in the earth.  It sounds like I best get some wire up and start listening, LOL! 

73

Bruce, KK4IKO

Hi, Floyd

It looks like I'm probably going to get an abandoned telephone pole between 30 and 35' high, unless the line crew come by to take it when I'm not home.  I'm retired and home most of the time, though.

I was thinking of a vertical on the pole and an inverted vee 30' in a tree.  I have the room for a half wave inverted vee on 80 meters.  I would like to be able to use 10 - 80 meters, maybe even 160, as my HF rig (Kenwood 820s) covers those bands.  What bands should I allocate to which antenna?  Local and DX is my plan, or is that too ambitious?  I can afford a decent vertical, but not a beam and rotator setup right now.

Looks like a change to my situation will be in the works soon.  The power company will be pulling a no longer used pole on my property (new poles and lines, last summer) and I've been told I can not only have it, but might be able to sweet talk the crew into re-planting it for me.  It looks to be about 30' or so above grade, and where I'm planning to put it will give me a small elevation advantage, as well as the 30'.  The pole is actually in very good condition, it's just that the new poles are bigger and taller to carry a second hot line.  That should open up new possibilities. 

I'm glad I'm not licensed to put my HF rig on the air yet, gives me plenty of time to work out these other issues without rushing to do something quick.  I'll probably test for General in September.

73
Bruce, KK4IKO 

http://maps.google.com/maps?ll=35.747922,-82.45208&z=13&t=h&hl=en

Here is Google Map Link to the satellite photo.  My house is next to the little smooth green spot in the center of the picture.  The ridgelines on either side are approx. 500' higher than my house, which is 2400' elevation.  The two ridges are about 3/4 mile apart, so I'm a little closer to the west ridge.

Thanks for the help, I appreciate all I can get.

73
Bruce, KK4IKO

I live in a mountain location with about a 15 degree elevation angle from my house to the top of ridges on each side (east and west).  I see a choice between a multiband vertical on the roof, or an inverted V dipole, behind the house.  The biggest difference besides initial cost is the dipole will require 125' or more of feedline, part of which will have to be underground in PVC.  I can stand the cost of the vertical (something like a Titan or Butternut) if there is a reasonable chance it will do the job.

Any North Carolina mountain hams out there?

73
Bruce, KK4IKO

Has anyone tried using braided trolling wire for antennas?  I saw some at my local fishing shop and wondered about this.  It is reasonably priced and comes in convenient 300' spools.  I would say kinking would be non-existent.  How is it fastened...knots or crimp sleeves?

73

Bruce, KK4IKO

Thanks all, for the information.

Not to sound like a smart @&*, but I wasn't looking for dissertations on the possible effects of RF exposure pro or con...I already know, having been an electrical/electronics technician all my working life (now retired).  I was just asking for knowledgeable opinions about exposure to a specific antenna in an area where there will be other people wandering around, which I certainly got from several folks.

The consensus seems to be that it won't be an issue if set up and used as described.

Bruce, KK4IKO

I'm building the portable 2m yagi in the June issue of QST.  I plan to mount it 10-12' above the ground next to my vehicle (Jeep Cherokee) on the opposite side of the vehicle from my operating position (sitting down next to the vehicle under a canopy).  My radio is restricted to 50W on VHF.  Is there any danger from RF at that distance?  The antenna will be hand rotatable, but not during transmission.  If I read Table B in the RF Safety section of the handbook correctly, this does not seem to be a problem.

Thanks.

73
Bruce, KK4IKO

Thanks KA1MDA for the info.

See my reply above.  The knob was already all the way onto the shaft, and still too easy to move.  I made a small adjustment which made the tension much more satisfactory.  Worked fine on the road today.

73

KK4IKO