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
_______________________________________________
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|