Gary Morton scribe:
At the recent FRARS radio rally I bough a cheap HB9CV antenna for 6m

Good antenna if you save space and like to be better than a dipole...

(there were no 3 element yagis on sale).

Don't worry abt.

out. My only concern was for the spacers to hold the "thin rods" away
from the main elements. The supplier wasn't particularly helpful. I have
a suspicion that the spacing may be critical,

It is. You should have a certain distance from the elements. Amount is not
to critical. I did a 6m HB9CV too. I followed the advice/plan o the
designer and use 5 mm plexi glass (spelling/naming??)

I am interested in how I can tweak the antenna to get a better SWR
reading.

That's the C and the element length

Am I right in thinking that the gaps between the thin rods
(name please!)

phasing lines needed to shift the phase by 215° (??) sri, not sure any more

and the elements is important

element lengths is important, yes

effect of too big, or too small, or an asymmetric gap?

a gap too small will severely detune the whole system

Also I was told that this antenna was about the same gain as a 3 element
yagi, possibly a little better. Was this just sales talk?

HB9CV:

4.2 dBi gain
~20 dB F/R

period

Regardless it does seem to work and I had my first QSOs using this
antenna. Since I am a QRP operator I would like to get the best out of
the antenna possible.

Sure a nice antenna and well worth the effort regarding the size.

Claus
DF8GH, JN48pa
htp://home.t-online.de/home/df8gh