When I went to Guantanamo Bay in 1970, and became KG4CS,
and ran the "only airline between the USA and Cuba", my
Base Passenger Transportation Officer job, "Barry BiPto",
had an airline that also went to/from Kingston, Jamaica
for our labor force, so I was able to get a JOGA QUAD,
made by Jose Gavin, XE3-something, in Merida, Mexico,
which had direct service to Kingston.
Because it was still only ham phone-patches from GitMO
to anywhere, with no overseas telephone service, any
new ham was MOST welcome, and as soon as my quarters
on East Bargo were assigned, the Public Works guy
drove me to see which of the 35 foot wooden "telephone"
poles I wanted moved and installed for my antenna.
Installed the next day, with a pulley at the top,
using a 1/2 inch line, I could easily raise and lower
the 50 foot section of 3 inch pipe used as the mast.
That quad's spreaders were made of (rectangular, 3/4 inch??)
Mexican Ironwood, with a wooden cube size 10 meters that then
supported outward and upward sloping wooden supports to
optimally space the 15 and 20 meter loops, with a single feed.
Of course, from KG4CS in 70-72 a 4 foot high dipole
worked the world, but that quad was super, and I
thought at least the mounting method worth sharing.
73
Barry, W5GN
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Jon
Pearl - W4ABC
Sent: Saturday, March 11, 2017 4:03 PM
To: Daniel Hileman <n9wx@hotmail.com>; TOWER TALK <towertalk@contesting.com>
Subject: Re: [TowerTalk] Cubex Mantis II
Hi Dan,
I don't have any experience with the Cubex 40m cubical quads but I still
have (stored away) a 4 element 10m-20m of theirs that I used for many years.
I'm a long time quad fan, starting with a 2 element Gotham with bamboo arms,
then a 2 element Skylane with fiberglass arms, then finally the 4 el. Cubex.
The weakest point in the Cubex design is the wire elements where they are
formed into corners. They are comprised of tinned #14 cu and pass through
drilled holes in the fiberglass arms. Over time, due to wind oscillations
the fiberglass will slowly abrade the wire causing failure. It does take
some time, though. My fix for this problem was to purchase a black air
shock, airline kit. I have the fiberglass arms stack on brackets on my
wooden fence and the short lengths of air line passing through the arms has
shown little deterioration from the years in the sun.
I cut the air line into lengths long enough to pass through (and then
some) each of the fiberglass arms (longer at the fat ends and shorter at the
small ends) with the wire elements passing through them. If I remember
correctly, as the fiberglass arms are shipped, the drilled holes are just
large enough to pass the supplied #14 but not the air line so I re-drilled
all of the element holes with an 1/8th in. drill bit. From that point on, I
never realized another broken element again.
There are a lot of written words out there by a lot of different authors on
quads vs. Yagis. Anecdotally, I know that as a kid getting ready to head
out the door for high school each morning, I'd always get up early to check
10 and 15 and was amazed to often hear that I was one of the first east
coast stations to be heard across the pond. Cycles 20 and 21 were pretty
good to me but so was the quad.
I'll close by mentioning that quads are three dimensional antennas.
I've always been lucky to have all of them mounted on crank-up and tilt-over
towers. When something broke, I could aim the boom end where the repairs
needed to be made towards the ground and then fold the tower over. On a
stick tower like the AN Wireless, if a wire element breaks on one of your
highest corners (40m), you're not only going to be dropping the antenna down
beside the tower, but it's going to have to remain in a boom-horizontal
fashion while you attempt to reach the upper corner of your 40m box.
Then again... you may well own a crane!
73, Dan,
Jon Pearl - W4ABC
www.w4abc.com
On 3/10/2017 9:52 AM, Daniel Hileman wrote:
> Hi Everyone,
>
>
> I am thinking about putting a Cubex Mantis II Quad (2 elements on 40m, 4
elements 20-10m) on my AN Wireless tower at about 72'. I am looking to see
if anyone has experience with this quad, or other 40m quads, and can tell me
how they like it. Looking for real life performance on 40m Vs a 2 or 3
element yagi? I know there is quite the debate on this, but not looking for
"opinions" with no operational experience between the two. This would be
quite an undertaking to install and looking for whether those with 40m quads
would do it again, and if they thought the performance was better/worse/same
as a 2 -3 element yagi.
>
>
> Thanks and 73,
>
> Dan N9WX
> _______________________________________________
>
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