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Old April 25th 06, 04:22 PM posted to rec.radio.amateur.antenna
 
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Default mobile loading coils


wrote in message
oups.com...
Thanks Cecil, I have some old fiberglass 11m antennas, the kind that has
a
wire antenna heatshrinked to a fiberglass rod that would be pefect for
making this. ....................................


You can use one of those for all those bands, just by changing the
top "stinger" whip. I use the small hose clamps to hold them, if the
stick doesn't have a slide in mounting part on top.
IE: if you had a 6 ft CB stick that used a short stinger, you can add
length to tune the lower bands. On one of mine, the stinger needed to
be about 2 ft longer to tune 20m using the CB stick. So if you had
various
stingers to clip on, you could work all the bands from 20-10.
On those upper HF bands, even the simple CB stick/extended stinger
will work quite well. A cb/10m stick using a longer stinger to tune
20m,
is more efficient than most 20m sticks using more turns of wire, and a
shorter stinger.
I have one antenna that I've used for nearly 15 years that was built
from a
firestick CB antenna. I added a large coil in the middle, and it works
all
bands 80-10. I change coil taps on the low bands, stinger length on the

upper bands.
I also have one I made from a 6 ft 20m stick. It's also converted to
all
band use, and has the performance of a bugcatcher, being it uses a
large
coil on the lower bands. But...it's as light as a fishing rod n reel...
I use a 5 ft stinger, and the normal driving height of the antenna is
11 ft.
That antenna is exactly center loaded in the driving mode. If I add a
3 ft
mast, it's 14 ft tall, with the coil at the 8 ft level. But I use that
when parked.
Bit tall for driving... :/ Anyway, you can build a pretty good antenna
dirt
cheap if you look around. I've never spent more than junk parts and
chump change for a mobile antenna.
MK


I had taken an old CB 6ft antenna, the kind with the wire heatshrinked to
the side and put new wire and a loading coil in the middle. Works OK on 10
and 15 SWR is pretty high on 20 and I dont have a way to match it.
Experimented with a cane pole for a support and found I could get a
reasoable SWR on 20 if the antenna was about 14ft long, a couple more feet
and I wouldnt even need the coil. Next plan is to try to use something that
folds kind of like fiberglass tent poles and get away from the loading coils
all together. They are more of a bother than what they are worth for my
application since I dont ham while Im driving. I just wanted something I
could store neatly in the back of the truck which would limit eveything to
6Ft or less. Changed my mind about 5 times now on what I want and how to do
it, I guess that happens when you are going up the learning curve.