On 11/17/2010 4:17 PM, J.Gordon Beattie, Jr., W2TTT wrote:
> Ed,
> Do what the manufacturer requires and you won't have trouble.
Remember the ROHN "dirt base". I'm planning on 50' of 25G, bracketed to
the end of the shop at roughly 18'. There will be a Force 12 C19XR at
50' and a WARC-7 at 60'. I'm using a 6' long, dirt base constructed out
of 1" solid rod with 6" X 10" X 1/8" steel face plates. The tower will
be guyed at roughly the 48' level using either 1200# test Phillystran or
3/16 800# test braided poly rope. I have no qualms about climbing said
tower
> Ask yourself who is climbing this thing and do you want to save a couple of
> dollars on concrete
At 30'?
> and then have to address an issue should there be a
> failure? There might be VHF and UHF antennas today and BIG YAGIS TOMORROW.
In my case, if I go with larger antennas I'd replace the tower at that
time. However I have used 40' of 25G on a dirt base holding a 5L KLM 20
meter monobander, guyed at roughly the 38' level. It withstood nearly 70
mph winds plus a monster ice storm that took out over half a mile of
power line, Behind the house the power line had such a load of ice it
was only about 4' off the ground.
However, I don't have room to swing the larger antennas on the small
tower any way so it's a moot point. Any thing big goes on the 45G
system which is guyed at 3 levels. The bottom two use 4000# test
Phillystran while the top tier uses 6000# test Philliystran. Guy
anchors are about 17,000# each.
> Don't take the risk.
Risk is relative and also depends on how risk tolerant the individual
is. I tend to be a risk taker with investments, but am quite
conservative when it comes to antennas, towers, and climbing.
73
Roger (K8RI)
> Thanks& 73,
> Gordon Beattie, W2TTT
> 201.314.6964
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Ed Swiderski, KU4BP
> Sent: Wednesday, November 17, 2010 9:09 PM
> To: TowerTalk@contesting.com
> Subject: [TowerTalk] Short tower base question
>
>
> All,
>
> I have a couple full pieces and one cut piece of Rohn 25 that I'd like put
> up against the house with a couple VHF antennas on it. (2m-16el and
> 432-18el) I plan on using a house bracket at about 3/4 of the height was
> wondering if a full size base is neccessary? I have been told by a good
> friend who used to work at installing towers that I can get away with a
> smaller than spec base in this situation.
>
> Thank you,
> Ed KU4BP
>
>
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