[TowerTalk] Looking for NEC models and hardware ideas...

Jim Lux jimlux at earthlink.net
Mon Jan 31 14:57:28 EST 2005


I'm working on a portable phased array demonstration, based on multiband 
trapped verticals, and I'm looking for some NEC models for them 
(particularly, the traps).

I'd also welcome suggestions on how to characterize the traps by 
themselves, say, with a MFJ antenna analyzer (test fixtures?)

Specifically, I'm using the Hustler 6BTV, which I now have 4 of.  They were 
selected on the basis of price, primarily, figuring that there's no huge 
difference in RF performance between the various versions  (among Cushcraft 
R8, MFJ/Hygain whatevers, etc.), and they appear to break down nicely into 
3 8 foot segments (which makes them "car top able").  Thanks to all who 
gave me feedback over the weekend to my request.
(I have to say that price was a big factor.. if the idea doesn't work, due 
to the vertical antennas, I'm only out $800 or so, as opposed to $2K for, 
e.g. R8s)


To issue of portability, I'm looking for ideas on quick connect/disconnect, 
other than the standard hose clamps. I realize that hose clamps which might 
actually work as well as anything else, especially, if you have a little 
collar on the "non-clamp" tube that positions the element in the right 
place when you slide the segments together.

The goal is to have the entire array able to be deployed/stored in 15-20 
minutes, so if it takes more than, say, 5 minutes to put a single antenna 
up, it's too long.  I think this is perfectly reasonable.. It only took me 
15-20 minutes to assemble one of them from scratch out of the box and go 
lash it to the kid's fort in the back yard. (obviously, I didn't do any 
tuning in that amount of time.. just tape measure adjustment, clamp it 
down, and we're done)

I'm also looking for a source for inexpensive, rugged waterproof cases 
(like Pelican cases) to hold the antenna base tuning and monitoring 
components.  Something 12x12x6 or thereabouts would probably do, perhaps a 
bit bigger.  I'd like something where the lid latches positively closed (so 
Rubbermaid containers don't hack it), and which is structurally rugged 
enough to stand being lashed onto a roof rack, or (although I don't plan to 
do this) survive being checked as baggage.  I'll probably need 5 or 6 of 
them (so you can see why $150 Pelican cases aren't really what I want!)

Jim, W6RMK




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