[TowerTalk] Cage Antenna Construction Hints?

[thompson@mindspring.com]

Subject: Fwd: Re: [TowerTalk] Cage Antenna Construction Hints?


>>I'm having trouble visualizing the cage antenna from all the descriptions.
>Can anyone point me to a picture, either on the web or in a book?

SNIP
>>At 11:46 PM 8/26/98 -0400, DavidC wrote:
>>>
>>>a coupla years ago W1CW made an awesome looking vertical out of a cage of
>>>wires which were around rings of PVC pipe.....he took a length of PVC
pipe >>>and cut it on the saw into a ton of short pieces....mebbe 1/2" or so
long >>>"pipes" - then attached the wires to one of these spacing them every
coupla
>>>feet.......it looks awesome....as to whether it really adds
>>>bandwidth...dunno...but gawd it looks really hammy!   73, Jim, K4OJ
>>>
>>>
>>>Jim:
>>>
>>>   Found the following on DejaNews, it may be another way to skin that
cat!
>>> :-)
>>>
>>>73, DavidC  AA1FA
>>>
>>>
>>>yo3ctk@alltrom.ro (Mihail Mateescu) wrote:
>>>
>>>>Hi everybody,
>>>
>>>>I wonder if someone has any practical experience with an unusual H.F.
>>>>antenna: G4ZU "canary cage" quad. I discovered it in an article in Radio
>>>>REF magazine, March 1978. According to author D. Nicolle, F6AZP, this
>>>>antenna was invented in 1957 and is covered by several patents


>>>The antenna is called the G4ZU Bird Cage.  The original article was in
>>>the April 1960 CQ magazine.  The antenna was made commercially along
>>>with his popular G4ZU 20, 15, 10 minibeam.


As you can see below the cage antenna is a multi wire dipole that broadens
the bandwidth  but has NO GAIN over a dipole.   The G4ZU birdcage and
slightly modified G4ZU canary cage is a version of the quad...an endfire
antenna with gain and directivity.   Please lets no get confused!

Dave K4JRB.

BTW:  Several of the antenna books show details of one way to do the cage
dipole.  Tom, W8JI also correctly pointed out that that a conical dipole
(wires spread out at the ends) does an even better job of broadbanding than
even the cage.  BUT THEY ARE ALL DIPOLES! 0DBd....




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