Howdy all:
As requested, pix of the new flagpole antenna here at K8XR in The Villages FL. Many thanks to
the TVARC club members & others who volunteered their knowledge & tips on flagpole antennas.
A lot of test-fitting to see what would work with what, started out with 2" white PVC,
soon learned that -
- standard Hustler clamps won't fit in 2" PVC, ears are too long
- standard heater hose clamps fit in 2" but then the traps won't slide in
- have to go to 2-1/2" PVC which is a special order item due to low demand
- 3" PVC would work & be cheaper but want to keep the weight & wind-loading down
First order of 2-1/2" was eBay, lotsa $$$, opened box to find transparent PVC (!) Would
work OK but not very low-profile, used it for the test-fits, these were 8' lengths. For final
build, ordered white 2-1/2", ended up with (2) 20' lengths (!) from Ace Hardware, used 1.
2-1/2" PVC ends up being a nice slip-fit down over the 6-BTV, the hose clamps are staggered
around the joints such that the antenna is kept centered in the PVC & thus centered over the
mount pipe, to minimize or eliminate any tendency to lean. The 2-1/2" is also a slip-fit over the
high-power 75M resonator, using 2" would require the use of the low-power mobile coil.
None of the components in this system - 6-BTV, DXE tilt base, etc - are designed for a flagpole's
weight & wind-loading, so additional strengthening was added everywhere it was feasible -
- the ground mounting pipe was upsized to 2" galvanized steel, set 40"' in the ground concrete
- the DX Engineering tilt base frame was drilled to take a third clamp to the ground mounting pipe
- the Hustler antenna base & DXE tilt bracket were drilled to use 8 bolts for assembly instead of 4
- the Hustler base had 3/16" aluminum side straps Heliarc weld added to make it into a channel section
- the DXE optional double-wall tubing first pipe section on the base was ordered & installed
The beefing-up of the Hustler base is to accommodate the weight of the PVC pipe, which just rests
on the top of the base but is not attached or fastened down, the 2-1/2" coupler is a slip-fit over the
base top insulator & centers the PVC assembly on the base.
The rest of the assembly & installation was straightforward & followed the DXE instructions and
recommendations with the exception of the ground radials, we used 17 gauge galvanized steel
electric fence wire, strong & cheap, $35 for a 1/4 mile spool, almost a lifetime supply. I prepped
the wire with a few knife strokes to thin the zinc, then crimp & solder the ring terminal. Gail did a
lot of the radial placement work, ended up using a battery lawn edger to cut a slot in the grass,
lay the wire in, use DXE hold down clips and then walk on the slot to close it up, put in 32 radials.
The lawn's been mowed twice since the radials went in, and they're already essentially invisible.
To add some stability, (3) 80lb monofilament fishing line "guy wires" run from about the 13' level
to the front corners of the house, they protect against winds from SSW thru NNW, not perfect but
better than nothing. The pole attachment is a short piece of PVC, slit to slide over the pole and
cemented in place, each line makes 2 turns around the pipe & tied, the short collar holds them up.
2 runs of DXE RG-8/X and 1 run of 8-wire rotor cable are in the 1/2" electrical PVC, to accommodate
a possible future remote antenna tuner, these were a tight fit, it worked but shoulda been 3/4" PVC.
The DXE 1:1 Line Isolator choke and its mounting shelf were included in the system, may be a bit of
overkill but put it in anyway.
The fiberglass landscaping base cover rock came from Home Depot, a small jig saw took care of the
needed cuts easily, no fuss, easy to handle, weighs about 15 pounds or so.
System checkout & antenna tuning was a surprise, as shown in the Excel file, who knew that a PVC
pipe cover would detune a trap vertical antenna so drastically. Ended up having to tune the antenna
off-frequency such that adding the cover would then bring it into resonance where desired. I might
do a little more touch-up on it in the future, as the footnotes on the spreadsheet show.
Overall the system performs pretty good, on 75 & 40 it's picking up a fairly strong noise source every
4 KHz that's annoying, some sleuthing is called for, the higher bands have been working into Central
and South America and Europe well, and having more band choices again than just 40 is really nice.
Total system costs for the flagpole antenna came to about 2,700, not counting the Hustler 6-BTV which
was already on hand, and not counting the installation of the ground mounting pipe in concrete, nor
burying the 1/2" conduit . We were going to redo the island landscaping anyway, so it was just a matter
of scheduling to have the landscaper do the pipe work for us for the flagpole install.
Any questions, feel free to ask.
Larry Sheridan K8XR
307-630-5697