At 05:24 PM 8/23/98 +0000, Terry Wright wrote:
<SNIP>
>The expertise of the people on this list is incredible!
Flattery will get you no where on this list ...sarcasm on the other hand.....
>I hope that my trivial question is not a bother as it is obvious you
>folks are very advanced in this great hobby. Here goes anyway.
Not to worry Terry most of us definitely don't have anything better to do
~8^) Those who do have something better to do should unsubscrbe and stop
wasting their time.
>I am in the market for a new self supporting tower and am new to the hobby.
>I am considering a Rohn HDBX-48. Nat. Electronics has 'em for $508.00.
>I want to go heavy duty for hf work some day.
>Is this a good choice and price?
For modest sized antennas the HDBX-48 is not a bad choice as long as you
understand its draw backs. $500 seems like a reasonable price for a new one
but they can be had for less than $300 if you can find a used one. I had a
HDBX for several years before I moved ( I wish I had could have moved it!)
So My comments are for that tower which has one additional 8' section,
otherwise I believe they are the same.
The good news:
1) The sections are fairly light weight and easy to handle. I put my 56 up
single handed. in two weekends.
2) Unlike the tubular Rohns it is easy to inspect the tower for rust and
there are relatively few places for problems to hide, if you ever have to
take one down (which is very easy to do, I took mine down in less than two
hours). I think they are a safer tower to dismantle for that reason. I had
a near miss on a Rohn 25 once.
3) There are no guy wires to mess with or to absent mindedly walk into and
it is slightly more pleasing to the XYL's and neighbors eyes. (but only
slightly)
The Bad News.
1) Because of the "X" brace construction they are a bit uncomfortable to
climb. I eventually decided that it was easier to climb with the tower with
my body centered on a tower leg rather than the face of the tower.
2) Because the tower gets wider as you come down , you have to constantly
adjust your safety belt as you descend or ascend. That is if you wear a
belt while actually climbing some folks don't use a belt during ascent or
descent...too each his own.
3) The HDBX-56 is only rated for a 10' boom and I believe the 48 is as
well. This is a little short for most antennas. This rating is because the
tower is not "safely" designed to handle the moment arm of a longer boom
with out twisting and possibly failing. I on the other hand chose to ignore
this, I had a Cushcraft A4 on mine about 7 sq. ft and an 18' boom. I
survived one storm with winds clocked to 70 mph..lucky? Probably. One way
of avoiding this problem would be to run the mast the full length inside
the tower and secure the rotator to the concrete base. You would need a
couple of thrust bearings along the way, but this would take the rotational
stresses off the tower almost completely and make servicing the rotator a
lot easier, again more expense too. I know of one such installation over in
Idaho . And if the rotator fails you can then arm-strong the antenna easily.
4) The HDBX series requires a lot of concrete for the base the cost of
concrete ran me $325 more than I paid for the used tower! You can get used
concrete for next to nothing but it doesn't pour very well. Plus digging a
5 ft deep hole was no walk in the park. Figure more $$ for a backhoe or
plan on spending several weekends digging it by hand and hope you don't run
into rock.
5) You cant use a standard gin pole to assemble a HDBX series tower. They
HDBX towers don't have tubular legs. Since most clubs have a gin pole for
ROHN 25 (and not for HDBX) you will have to improvise. I Used a 6' piece of
1 1/2" pipe with a U bolt at each end. This in turn was bolted at the
center of the X braces on the faces of the tower. I then used the Rohn 25
gin pole attached to this piece of pipe. It worked pretty slick but was
slow going because I had move both the gin pole and the "adapter" each time.
Good luck
Dave
K9NX
..
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