|
Ok Alan, ..laws
That's easy , just claim there linked to dark
matter , then anything go's : )
A ground mounted ui-pole , is it really just
a short thin loop ? , if the ATU
earth is bonded to the ground point ? ,
IF..the current at the earth and
at the feed point are equal and
opposite , then nothing will happen , or
have I missed something ? or is there
a diminishing distribution , but over a short
loop , what go's out , must come back to
the tuner ? what's radiating or is it
establishing a near field by cancelation ,
ala counter-would ? .. Its something that could be
erected in the uk 20x40 back plot..
This talks of top loading and 'ground
reference system ' what ever that is , no
info , unless its a tuned counterpoise ....
something I had not though of , tuner in the
earth line to match to the ground z on
477 .... what happens at commercial mw
sites , marine wise the hull is earth ?
appears to have a cage of wires
to increase the tower diameter , the tower
is actually broken up with insulators , once again
, may be the effort should be in establishing
a top loaded vertical cage / top ,loading
and not a multi wire top ?
bbc mw tx side
nav text mf Ae
Ranges on the radiation plot look
familiar 250/300 K first skip ?
73-G,
Sent: Friday, May 08, 2015 5:28 PM
Subject: LF: Re: UNIPOLE V INV-L ?
Hi G,
Well the Laws of Physics dont change however much
one might wish it :-))
The unipole will be approx -3dB ERP on the inv
L
Effective height of unipole approx half physical
height
Effective height of inv L same height with 1.5*h
top is approx 0.9* physical height
inv L disadvantage.....requires another support and
insulators
inv L advantage ........over poor ground with the
same feed-point grounding the inL will have lower ground loss and higher
capacity. Over good ground or sea-water this advantage may disappear, but losses
will be low anyway.
I think this folded monopole is covered in Rik's
tutorial, the extra wires are just "matching" they dont increase the radiation
resistance. Commercial stations like grounded aerials for lightning
protection.
Alan
G3NYK
----- Original Message -----
Sent: Friday, May 08, 2015 4:54 PM
Subject: LF: UNIPOLE V INV-L ?
UNI-POLE V INV-L ?
Assuming a robust ATU and earth
What would be the advantage / disadvantage
of say a 40 foot uni-pole
, to a conventional 40 x
60 ft inv L at MF ?
tower and side wire or RG8U /
copper pipe construction ? ......... -3 dB of a
similar size loop ?
73-Graham
G0NBD
| 
