[Icom] Mobile antenna considerations

[Ray V.]

I've used various mobile antennas over a span of 40 years including a 
hand tapped coil in the trunk of my '57 chevy convertible feeding an 8' 
whip back in the very early 60's. First rig was a homebrew 
transmitter/BC band converter. Later an SR-500 and eventually a KWM-2. 
Every time you changed frequency on 75 meters more than 10kc or so I had 
to stop, open the trunk and move the tap. Later went to Hustler and that 
only gave me a span of 25kc on 75 meters, then I'd have to stop and move 
the adjustable whip up or down. You teneded to stay in a very narrow 
frequency window. That got old real quick. I tend to agree that on 
160,75 and 40, the center loaded whips do have a good advantage. I 
haven't used a screwdriver yet but I expect they are in the center 
loaded class. However for ease of use and convenience I have settled on 
an SGC-230 tuner/SGC-303 helically wound whip system. I've found it to 
be adequate (not great) on 160 and 75 and works fine on 40 and above 
with my IC-706MkII. The major factor for me is the nearly instant 
tuneup. Nothing to do but push the PTT button and start talking, the 
tuner senses the RF regardless of band and in 1/2 second or less the 
match is made. The only place this doesn't work well is on 160. That 
usually takes 5 seconds or a little longer to find a good match if the 
exact frequency isn't in the tuners memory. And of course performance is 
very poor on 160, but I have made a fair number of mobile 160 meter 
contacts using this system. I do have my tuner mounted to the bulkhead 
of my truck with only a 10" piece of wire running thru the bulkhead 
attached between the tuner and the antenna base on the outside and the 
antenna is mounted as high as possible on the truck, not down low on the 
bumper.

73, Ray  W2EC