Wire size is always put in relationship to its wave length 0.01:1 is a
comfortable ratio. 0.001:1 may cause a mild concern of bandwidth. That will
generate band selectivity and can cause some channel are more effective
than another across the RC band. Over all wire size variation can cause
much less impact than wire length (0.25wave on groundplane, 0.5wave air
borne). Once again, we are using a ground base antenna in air borne
applications that is electrically incorrect. I use 0.5wave across my 2m
planes, or 0.5wave in "J" tips for my HLG.
If CF is inevitable, we may apply "skin effect" on antenna theory. In
principle, imagine a CF boom inside an aluminum tube-antenna. Majority of
RF current flow at the outside surface of metal tube, that effectively
making the CF transparent. knowing that the tail boom has a high aspect
ratio, a practice 2nd best to the outside tube may be considered. That is
to split a single wire into two equal length and run it outside the CF in
all parallel arrangement. We would expect the RF one each paralleling wire
to repel one another and concentrated at the far outer portion avoiding
"seeing" the CF in between them. Any metal lengths or push rod MUST carry
signal current "in phase" with the antenna current. That can be met by
treating them in same fashion as a member of the team of split wires,
except it stay at the core. However, all lengths must be equal to comply
the "in phase" requirement.
Aluminum strip with adhesive is one idea that comes into my mind at this
point (only if you can make reliable electrical contact at all times
without soldering connection). Copper although is solderable, some may
think that is too heavy. I would use copper. When ever affordable, use 4
split parallel wire can produce improved result. The split wire ending near
stabilizer need not be electrically connected together, but wire tips
should not flare/diverge from one another by more than 0.05 of full wire
"length". Dealers and vendor, can pay attention to this potential
marketing opportunity, for "thin" copper foils with adhesive. :-).
Let me know if I have missed any relevant points.
_YK
in Seattle
- Original Message -
From: Antonio Martinez <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, May 27, 2000 12:41 PM
Subject: [RCSE] antenna wire size
> I know this has been addressed in the past - but I wasn't paying
attention
> (sorry YK)... Does the size of antenna wire matter, or just the length.
I
> have been using a pushrod as the antenna in my HL, but I'd like to use CF
> rods instead. This means I need a bona fide antenna. I was hoping to
use
> wirewrap material (very fine dia copper wire) glued onto the fuse
exterior.
> Any antenna engineers out there?
> TIA
> a
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