HB9CV doesn't tune up
 

Gary -

Look at these web sites.

L.B. Cebik, W4RNL basics on the HB9CV antenna.
The HB9CV version of the 2-element phased array appeared in 1961. In Europe,
some writers refer to almost any 2-element horizontal phased array as an
HB9CV, while the English-speaking world tends to refer to the ZL- Special to
mark the genre of antenna. The HB9CV version of the antenna and many
variants are widely used in Europe, with Christmas tree stacks for 20- 15-10
meters. Users swear by them, claiming near to, and sometimes better than,
3-element Yagi performance.
http://www.cebik.com/hb.html

There are a number of "copies" and homemade versions
of this antenna on the market
http://www.page.sannet.ne.jp/ja1hwo/...4elhb9cv_e.htm

http://www.alfa-tango.com/ant/hb9.php4

Make sure that the former owner did not "modify" this antenna
http://davidkearns.co.uk/G8TTI/HB9CVdetails.htm

http://www.wimo.de/verteiler-e.htm?s37a_e.htm

This is the 28 MHz version
http://14at259.chez.tiscali.fr/hb9cva1.htm

73 de Greg
w9gb
--
DO NOT use Reply.
Only reply through ARRL forwarding service to W9GB


"Gary Morton" wrote in message
...
At the recent FRARS radio rally I bough a cheap HB9CV antenna for 6m
(there
were no 3 element yagis on sale). When I got it home I noticed that a hole
had
worn in the plastic and that some bolts and spacers (for the gamma match
elements - if that is the right description) had fallen 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, but the supplier didn't seem knowledgeable.

[ SNIP ]

regards...

--Gary (M1GRY)

G.Beat wrote:
Gary -

Look at these web sites.

L.B. Cebik, W4RNL basics on the HB9CV antenna.
The HB9CV version of the 2-element phased array appeared in 1961. In Europe,
some writers refer to almost any 2-element horizontal phased array as an
HB9CV, while the English-speaking world tends to refer to the ZL- Special to
mark the genre of antenna. The HB9CV version of the antenna and many
variants are widely used in Europe, with Christmas tree stacks for 20- 15-10
meters. Users swear by them, claiming near to, and sometimes better than,
3-element Yagi performance.
http://www.cebik.com/hb.html


73 de Greg
w9gb

Greg,

thanks for the pointers. I have already used Google to do searches for
information on this antenna, but some of your pages were new to me. I see that
there is some software to design a HB9CV. This may be helpful in checking the
antenna which I bought.

regards...

--Gary

Helgina Koosmaen wrote:

....original message snipped....

As at all radio rallies - its a case of "Caveat Emptor" - Let the Buyer
Beware.

I don't disagree, particularly since I am still a beginner as far as antenna
theory and practice goes.

Can you answer any of my specific questions?

regards...

--Gary

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

HB9CV:

4.2 dBi gain -- 4,2 dBd, of course
~20 dB F/R