On 8 Jul 2005 04:04:02 -0700, "Blue Dawg"
wrote:

It really looks weird up there without a reflector on it.
I may put a reflector on it but am stumped as to length of the
reflector (ging to be made of 1/2" electrical conduit).

Hi OM,

It's going to look quite odd with that conduit (no physical strength
to speak of) drooping in the wind. And it would look odd if it didn't
droop, being so much bigger:

I can't find
the formula for the length taking into consideration of the diameter of
the reflector. I believe that the 'stand-by' one should use 468/f.

Well ±

The formula neither takes into effect the larger diameter of your
"wire" reflector, nor its reflector size (which would be approx 5%
larger than you might expect).

Using 27.185 (Chl 19) the length should be 17.22 feet. Only thing is
the length of the driven element is less than 12' because of the
antennas having the centerload coil in them.

And your point is?

If you want an expected outcome, you do what you have to do and get on
with it. In your case, if you are seeking elegance you would then buy
two more units, clamp them base-to-base, put them about a 20th wave
behind the first two, and tune the reflector (make it bigger) by that
same roughly 5%.

If you haven't already noticed all the loose terms (about,
roughly,...) then you may think that was the end of it. But no,
there's more! How much more depends on how deep you research these
size and distance correlations, or simply take someone's word for it
and build an aircooled dummy load.

73's
Richard Clark, KB7QHC

On Fri, 08 Jul 2005 09:40:29 -0700, Richard Clark
wrote:

if you are seeking elegance you would then buy
two more units, clamp them base-to-base, put them about a 20th wave
behind the first two, and tune the reflector (make it bigger) by that
same roughly 5%.

Hi OM,

If you may notice the disparity between my post in this particular and
KB5WZI, Richard Harrison's (which is far better researched) then you
may note also his warning for element diameter (your conduit is not
"thin" by any stretch of the imagination to suit precision and text
book formulas).

73's
Richard Clark, KB7QHC

Richard, are you saying to go buy two identical antennas and mount them
the same sans coax and then also put another reflector behind the 2nd
one, ending up with a 3 element Yagi?
Cliff


"If you want an expected outcome, you do what you have to do and get on

with it. In your case, if you are seeking elegance you would then buy
two more units, clamp them base-to-base, put them about a 20th wave
behind the first two, and tune the reflector (make it bigger) by that
same roughly 5%.
"

On 10 Jul 2005 21:53:28 -0700, "Blue Dawg"
wrote:
Richard, are you saying to go buy two identical antennas and mount them
the same sans coax...

Hi Cliff,

Put them back about ¼ wave, and tune them about 3-5% lower in
frequency = Two element yagi. If you want to chip in two more, you
can build them as directors.

73's
Richard Clark, KB7QHC