In a message dated 10/30/98 12:38:26 AM Eastern Standard Time,
wbcapps@mindspring.com writes:
> i'm going to put up an inverted vee this weeked for topband 160 meters. I
> have a pine tree that i have a rope over that at it highest clear point is
> around 55-60 feet. I was trying to decide which feed line is best. I have a
> bunch of ladderline that i could feed the dipole with, or I could go
> purchase some coax. Has anyone had any luck using ladderline to feed an
> inverted vee, or should i use a coax feed line? also, any advice on spacing
> of the legs of the vee, say 90 degrees, less or more?? What happens if the
> Vee legs are close together say 45degrees, with a forward attitude to them.
> (like a sloper dipole)I have a small city lot, with many trees to dodge. My
> home may not be a good top band location.
>
Hi Bill,
The best is to use 50 ohm coax, your inverted Vee is very close to 50 ohms,
regardless of typical angle that terrain, situation allows. Get the legs as
far as straight as you can. Rest you can bend to fit the property. Trim it to
resonate around 1830. Changing location/height of ends will slightly change
tuning.
I have mine at home QTH in NJ up in a tree at 35 feet, angle is more than
90 degrees, one leg is straight, one end is bent about 40 feet from the end.
Got 1:1 SWR at 1823, I do not use balun. It works fine on all other bands
except 80 m (voltage feed point), rig's tuner matches it fine.
If you can complement that with KM1H Slinky Beverage (about 5 slinkies
stretched over abt 150 ft, 600:50 ohm transformer, terminated or not) it will
help to improve your S/N ratio and improve reception. Otherwise your Inverted
Ve at many times around the sunset/sunrise will beat even beverages and you
might be able to briefly hear stuff that "Big Boys" hear all the time.
I found this setup to be the most efficient for limited situations.
Next best
thing would be to have some vertical top loaded L or T configuration, with few
elevated radials. This is possible with houses surrounded by trees. Use two
trees to support the top of the Tee, run wire down to feed point at the roof
top. Have two or four elevated sloping quarter wave radials (or bent). (Hide
your telephones and answering machines!)
The "bestest" thing is to use balloon to support the straight vertical.
They
also present 50 ohm impedance, no matching or lossy tuners necessary. Again
beverages, slinkies, small loops, pendants, ewe help tremendously to
discriminate against local and band noise. I am even using "dog loop"
underground antenna, which is wire loop around the perimeter of the property,
about 800 ft of insulated "dog fence" wire (stranded #16?) with, have 600:50
transformer at the feed point and using preamp. It is invisible and works.
You can for the duration of night run wire "beverage" on the ground, street
gutter, etc. Done it for contest nights.
Good luck and see you in the contests!
Yuri Blanarovich, K3BU, VE1BY, VE3BMV
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