[600MRG] Loading coils....

Fri Dec 19 08:02:41 CST 2014

I can't speak too highly for a vertical wire LOOP used for transmit and 
receive...

1. It is *way* more quiet on receive...
2. It uses *way* less wire than a vertical monopole with a zillion wire 
radials in an insulated ground...
3. It tunes very nicely from 17.2kc. to 10 meters and works best here, 
over all... It always sees SAQ...
4. It's a 600' vertical loop made from 'dog wire' sold on E-Bay for <100 
bux and is all you need plus a vacuum variable and a good core for the 
transformer...

If you are on salt water or at the shore then the vertical will do 
fairly well, but inland here where the soil conductivity is very poor 
then the vertical makes a decent dummy load but it does get out, sorta...

With pine trees @ 75' plus, it becomes simple to shoot a line over the 
tops with a 55# compound bow and no insulators are necessary with that 
quality wire from e-bay... At about 10KV I get some corona but no melt 
down...
So it is simply just 600' of wire 70' x 550' strung vertical and I have 
been heard from W6 to SV8 land and still consistently copy west coast 
stations and EU very well most all the time...
I can't think of any improvement so I just took down 7 high pines and 
now a 1000' vertical loop is looking good to go...

http://www.ebay.com/itm/14-Gauge-Heavy-Duty-Pro-Grade-Dog-Fence-1000-Continuous-Wire-Invisible-Fence-/230870672771?pt=LH_DefaultDomain_0&hash=item35c0f6e583

TNX from DaveR/XSH17  'we hear you'

On 12/19/2014 3:54 AM, Edward R Cole wrote:
> Ken,
>
> I am no way an expert on HF antennas, but there are many ways to load 
> a short antenna.  Your base coil is adding inductance in series with 
> the coax line which is grounding the base end of the coil at the tuner 
> if it is not grounded before reaching the tuner.  Hopefully you are 
> using a good ground on the tuner.  Your tuner probably is adding 
> inductance as well.  The coax line is part of the antenna since it is 
> not grounded at the coil.  You mention a 40m trap which I assume is 
> transparent below 7-MHz.
>
> I feed an inverted-L which is basically a 43-foot high vertical with a 
> long top hat (two 122-foot wires separated 2-foot but connected at 
> both ends electrically).  That make it possible to run with a smaller 
> base loading coil.  My coil is grounded on the far end and I tap off 
> the coil about 2-1/2 turns above the ground end and connect coax.  I 
> use no tuner as the coil is tuned for resonance and the tap for 50-ohms.
>
> Be interesting to hear others comments.
>
> 73, Ed - KL7UW
>
> At 08:44 PM 12/18/2014, Kenneth G. Gordon wrote:
>> OK. I just realized that think I may have a misconception here about
>> base-loading coils for verticals.
>>
>> I have a 55' tall vertical, which was originally designed for the 80 
>> and 40
>> meter ham bands. It has a combination trap/loading coil at the 33 
>> foot level,
>> so that the antenna acts as a 1/4 wave antenna on both 80 and 40 meters.
>>
>> I feed it with 50 ohm coax, and use a home-brew antenna coupler at the
>> transmitter end to load it on all bands, including WARC bands.
>>
>> It works very well, considering that it is a vertical.
>>
>> Furthermore, it is the only antenna I have.
>>
>> Last year, I added a base "loading coil" to it so I could operate the 
>> antenna
>> on 160 meters.
>>
>> I also calculated and bought the necessary "stuff" to make a 
>> base-loading
>> coil for 600 meters.
>>
>> Now here's my confusion: when I used the base-loading coil on 160 
>> meters, I
>> connected one end of the coil to the antenna, and left the other end
>> "floating". I.e., not connected to anything.
>>
>> Then I tapped down on the coil in the direction away from the antenna 
>> until I
>> was able to obtain a 1:1 SWR on 160 meters.
>>
>> This worked quite well, and I managed to work Europe twice with this 
>> combo
>> and 100 watts on that band.
>>
>> So, what was actually happening?
>>
>> What is confusing me is that I THINK I recall seeing base-loading coils
>> added to verticals, like for a car, but the "far" end of the coil is 
>> grounded, and
>> the coax was connected to a tap somewhere above the ground point.
>>
>> This, to me, means that the coil + antenna must FIRST be resonant at the
>> operating frequency, and THEN the tap for the feedpoint must be 
>> chosen to
>> match the coax impedance.
>>
>> So, what was happening when I did NOT have the "other" end of the coil
>> grounded, yet the system worked very well?
>>
>> BTW, it took only about 2 turns of a 4" diameter coil wound of #12 
>> wire on a
>> ceramic form to achieve the match.
>>
>> I now suspect that my antenna coupler was providing the necessary extra
>> inductance to enable the match.
>>
>> In addition, I cannot find my ARRL Antenna Book right now... :-(
>>
>> Ken W7EKB
>>
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>
> 73, Ed - KL7UW
> http://www.kl7uw.com
>     "Kits made by KL7UW"
> Dubus Mag business:
>     dubususa at gmail.com
>
>
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