|
New to Ham Radio?
My Profile
Community
Articles
Forums
News
Reviews
Friends Remembered
Speak Out
Strays
Survey Question
Operating
Contesting
DX Cluster Spots
Propagation
Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers
Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net
|
|
1-3 of 3 messages
|
Page 1 of 1
|
|
2-meter Quad that can be mounted on a camera tripo
|
Reply
|
|
by KB3KYO on July 19, 2004
|
Mail this to a friend!
|
I'm going on vacation in a month, and my goal now is to make a quad that I can take with me and aim (Fred Flintstone method) wherever I want.
The plan I'm currently interested in is here: http://www.softcom.net/users/kd6dks/quad.html
Would this be mount-able on a camera tripod, to make it easy to swivel around? Or is there a better way (will be spending several nights in a cabin in the woods).
|
| |
|
RE: 2-meter Quad that can be mounted on a camera t
|
Reply
|
|
by KE4DRN on July 20, 2004
|
Mail this to a friend!
|
hi scott,
nice antenna, I have one of them too.
That will work but the higher up in the air
you get this quad (or other antenna) better off you are.
Not to talk you out of the quad, have you seen this
antenna, called the half square.
http://www.cebik.com/hs.html
Easy and light weight you can build it for a few bucks or less if you have the wire, coax and pvc pipe.
You can attach it to a 10' length of 1" pvc pipe
and point it anyway you like.
73 james
|
| |
|
RE: 2-meter Quad that can be mounted on a camera t
|
Reply
|
|
by WB6BYU on July 20, 2004
|
Mail this to a friend!
|
Personally I prefer the W4RNL dimensions (www.cebik.com).
He has a BASIC calculator that takes as input the
desired frequency and wire diameter (which does make
a difference!) and generates optimized 2, 3 and 4 element
dimensions. (I converted it to a spread sheet and have
built them for several different bands, with good
results.)
There are several factors to consider in choosing a
quad and how to install it. The first is height: this
is often more important than design gain. I suggest
you start by thinking of how you can get your antenna
up 12' to 18' off the ground, then consider how large
of an antenna can be supported at that height. Simply
leaning a mast against the side of the cabin may be
adequate in some cases. Unless you are on a hill, I
wouldn't be surprised if an omnidirectional antenna at
20' outperformed a quad mounted on a camera tripod.
(A roll-up J-pole hoisted on a tree branch would be
smaller/lighter/cheaper to build.) Depending on the
wind, a camera tripod probably won't hold up a quad on
a 10' mast unless it has some other support. A couple
of bungee cords around a fence post or porch rail
support might be better.
The next question is transport: how heavy and bulky
can the antenna be and still be practical? A 4-element
quad that doesn't disassemble is going to be awkward to
fit in the car with your other luggage. I build mine
using PVC pipe and all the joints come apart, so the
elements stack flat. I also have some yagis where the
elements store inside the boom, making a 1-dimensional
package. My personal favorite for a small portable beam
is the "tape measure yagi", which easily colapses up
small enough to fit in a carry-on bag on the plane.
Clearly your choices may be different if you are driving
to the cabin in a motorhome or hiking 10km to get there. If I were driving in your situation I'd probably
take 24' of military mast sections (or my 12' telescoping
squeegee handle) with enough rope to guy it if needed,
and a 2- or 3-element quad to put on top. Remember,
the more gain the antenna has the more accurately it
must be aimed: unless I have a good way to secure the
antenna so the wind doesn't blow it around, I probably
wouldn't go over 2 or 3 elements.
Of course, for a major VHF contest you would take
bigger masts and antennas, along with suitable rotators.
If you have any questions on the antennas I mentioned
send me an email and I'll try to find descriptions of
them.
Good luck! - Dale WB6BYU
|
| |
|
Email Subscription
You are not subscribed to this topic.
Subscribe!
My Subscriptions
Subscriptions Help
Check our help page for help using
Forum, or send questions, comments, or suggestions to the
Forum Manager.
|
|
|
