Topband: Response to W8JI's comments about using a K2AV folded counterpoise at VK6VZ

[Steve Ireland]

G'day

 

Tom wrote a number of comments about my nice results with a 3/8 wave
inverted-L fed against a K2AV folded counterpoise back on 26 August. I went
into hospital a few days later for a routine operation but ended up with
pneumonia and then influenza, so never got the chance to reply.  

 

Those who are interested in the FCP performance may find the discussion
below food for thought:  

 

 

>> VK6VZ: Having read about the K2AV folded counterpoise, which I could
mount along one side of the half acre block here, I decided to (once again) 

>> try a Marconi antenna.  With the counterpoise in this position, I put up
a 3/8 wave inverted-L antenna with a 100-foot vertical section (the 

>> antenna is 100-foot up, 100-foot out, similar to that used by K2AV).

 

>W8JI: So you had multiple verticals before that disappointed you, always
had more success with an Inverted V.

 

Absolutely.  Quarter wave, 166' and three-eighth wave Marconi antennas with
45 - 50' vertical sections were used over a fifty-radial W3ESU/K8CFU
mini-poise (old topbanders will know about this) in one backyard location
(1997 - 1999). From another backyard location (2000/2002?), a quarter wave
Marconi-T with a 66' vertical section was used, over thirty 60' to 100'
radials. 

 

All the Marconi antenna systems worked OK, but not as consistently well as
an inverted vee half-wave dipole at 90' locally or on intercontinental DX
(and all other continents are a long way from Perth).  Still early days, but
the 3/8 wave Marconi and K2AV FCP are looking like the best 160m antenna
ever from here.    

 

>W8JI: Now you have a new antenna in a new spot with a new counterpoise that
also, because of lengths, has considerable horizontal component.

 

Yes.  But remember that all my previous Marconi antennas with the exception
of the Marconi-T had considerable horizontal components.  Most had 100'-plus
horizontal sections.  Also, the sizes of the vertical sections of the
previous Marconi antennas were limited by where I could put a sizeable
circular-ish/squarish radial field under the antenna.  

 

As the K2AV is simply 66' long and takes virtually no space in the two other
planes, all of a sudden on my limited block I can get up a really
seriously-sized vertical section.  

 

>W8JI: I know this might ruffle some feathers, but when we want to evaluate
a counterpoise change, we really should change only the counterpoise and the
antenna should not freely allow horizontal component. Otherwise we really
don't know what part really did what.

 

As per my previous comments and original email, the places where I could put
up a radial screen limited the size of the vertical section of my Marconi
antenna.  The FCP frees me to put up a Marconi just about anywhere where I
want in the yard - with the biggest amount of vertical section in it. The
whole point of my original post was that using the K2AV counterpoise meant
that I could use a much improved Marconi antenna - in both the length of the
vertical section of the antenna and the height of the horizontal part of the
antenna.

 

I think it is far more positive/practical for people with small yards to
simply re-evaluate how they could use a K2AV FCP to improve their antenna
system as well - by relocating the latter.  

 

>W8JI: Now you have a 100 ft long horizontal up 100 feet fed by a vertical
wire that might not even be radiating much if it is near a tower.

 

My antenna system can be described in so many different ways - your way
sounds pretty negative.  I don't care how anyone describes it though -
because it works so well for me. ;-) The tower has been prepared so it is
well and truly detuned from 160m.  My ground-wave reception and signal has
gone through the roof - ask the local VK6 160m ops.

 

>W8JI: I changed the front tires to new economy six plies, fuel tank shock
mounts, changed a fuel filter, and repaired the fuel tank crack on my
tractor, and the new front tires let me mow twice as far on a tank of fuel.
:-)

 

Jeez Tom, sorry about that mate. Luckily I found the crack in my tractor's
fuel tank and could then afford some better injectors - now she takes less
fuel and pulls a bigger load.  ;-)

 

Vy 73

 

Steve, VK6VZ