Ah Ok, Rik,
Well my loading coil is also at the top of the vertical section , so looks
like your array is very similar, i found the layout to work very well on
500 , the vertical section and the capacity section are in a cleare location
, the far end being attached to the house ... Ill try altering the
inductance .....
The ground system , i think will play a part using the system on the higher
bands , it would be intresting to see what is 'happeing' to the v/h on
1.8 and 3.5 ..
I can re-arrange the top section into a phase cancelling section , with 3
wires , feeding the center section with the returns via the outer section
Note the comments on earth system at lf , its the affect of the wires at
higher fequencys that was behind trying to model the array as its
performance falls off sharply over 5 mhz ... may be it turns into a faraday
cage ?
Tnx
Graham ..
----- Original Message -----
From: "Rik Strobbe" <[email protected]>
To: <[email protected]>
Sent: Friday, December 28, 2007 8:34 PM
Subject: Re: LF: -HELP- MMANA-GAL Antenna analyzer .... can anyone'code'an
array ?
Hello Graham,
the load (= loading coil) is at a rather unusual place: at the top of
the vertical wire. Or to be exact, one segment below the top.
If you want the load just above the feeding point just change "w1e1"
into "w1b1" (= one segment from the bottom).
The "trick" with MMANA is that wires only interconnect at their ends,
so the correct interconnection between a single vertical wire and
multiple horizontal wires is a bit tricky and need an number of short
wires.
Regarding earth: any wire at zero height is considered to be grounded.
So no need to worry about that.
As mentioned by G3YMC ground(loss) is not taken into account for the
impedance conculations. In my opinion this is a good thing, as this
allows to calculate the radiation resistance even al low efficiency.
At 136kHz and even at 500kHz it would be hard to calculate the losses
as greenery often plays a much larger role the soil. Beyond that the
waves penetrate that deep into the soil that only in very few cases
you can assume the ground is a uniform layer.
73, Rik ON7YD
Quoting Graham <[email protected]>:
Ok Thanks for that Rik,
Thats the basic layout , ive only 2 top wires , but thats the layout ..
I see you have a load defined in the geometry listing , but where on
the ae is it located ? , I found one post on the user group , where a
element could be given a short lenght and have inductance added to it
.. that way you could control where the coil was placed
My ae has the 'coil' at the 90 deg bend , top of the vertical section ,
if i could work out how to add that, I would be half way there ! the
earth system would be the other half hihi
Tnx
Graham ..
----- Original Message ----- From: "Rik Strobbe"
<[email protected]>
To: <[email protected]>
Sent: Friday, December 28, 2007 5:49 PM
Subject: Re: LF: -HELP- MMANA-GAL Antenna analyzer .... can
anyone'code' an array ?
Graham,
attached a MMANA-GAL file that simulates my 136kHz antenna when
adapted for 500kHz.
Maybe that will be of some help.
73, Rik ON7YD
Quoting Graham <[email protected]>:
-HELP- MMANA-GAL Antenna analyzer .... can anyone 'code' an array ?
After several attempts .. and getting no-where fast , Is there anyone
who can code a top loaded antenna array ? the array is in the shape of
a inverted L . with top loading coil and 2 wire capacity section
I can find some similar files , but can I add to them .... not as yet !
It 'works' up to about 5 mhz , then falls over , I have a feeling
the earth system is playing a part in this ... also how do you code a
parallel 2 wire section ?
Any help would be appreciated ,
Tnx
Graham
G0NBD
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