Lost Frogs Records

Subject: G3TXQ HexBeam Progress
From: Dave Matthews
Date: Wed, 02 Jul 2008

I have received the fiberglass poles and spreaders, and the baseplate
with holes drilled, and the u-bolts. The fiberglass came from Marietta
GA, the baseplate from Lawrenceburg TN(!) I ordered on Monday and all parts arrived today.

I will be following instructions for assembly from this website:
http://leoshoemaker.com/hexbeambyk4kio/general.html



Date: Fri, 04 Jul 2008

Today I glued up the spreaders with 'Liquid Nails' as instructed. I had to keep fiddling with the pieces as the glue firmed up, the sections wanted to creep out a bit during drying time. In the end everything looks good, all close enough to 144" to work fine. Also, I put the base plate components together. I drilled a 3/4" hole in the base plate for the coax feedline, that was the only hole not predrilled in the base plate.

Tomorrow if the spreaders feel firm enough I will start with the primer coat of spray paint.

 

Date: Sun, 06 Jul 2008

I'm letting the primer coat dry before the final, green, paint. I will order the wire tomorrow. Just for interest below is a link to the hex-beam yahoo group, and a message that is -very- inspiring.

http://groups.yahoo.com/group/hex-beam/

I finished the 5-band G3TXQ Broadband Hex Beam a few weeks back. I followed K4KIO's outstanding step-by-step plans, used his materials
list, and studied his photos. No problems were encountered.
I'm not used to an antenna being this flat across so many bands...with terrific F/B and genuine gain. I'm also not used to so many 'big signal' compliments from all continents. I have a variety of wireantennas at about 60 feet. Its rare to find a station that is not 2-3 S-units stronger on the the Hex beam. Where the wire antennas may have a null, the difference can be dramatic.
To say that this antenna has exceeded my expectations, is an
understatement. I am thrilled with the beam.
73,
Bill WY3A

Date: Mon, 07 Jul 2008

Green paint is on, including the connector blocks. I went to Lowe's and
got the stainless steel hardware including the hose clamps. This
morning I ordered the 16ga wire for the antenna. I guess now all of the
buying and prep-work is finished, assembly will start after the paint is
cured.

I found that I used TWO full cans each of the primer and the top coat
spray paint, despite the parts list indicating one can each.

 
Date: Tue, 08 Jul 2008

I got the wire in today, and I just ordered it yesterday! Thanks
WireMan!

http://www.thewireman.com

The wire was a bit pricey at $54 (300'), plus $9.50 shipping, but it is
a very nice tinned flexible wire, their "model 519, 16ga tinned silky". And
the name silky does in fact describe the feel. No complaints here about
the price and the delivery was next day!

By the way, I am keeping all of the receipts to make a grand total cost
of this antenna, and that will be published when it is finished.

 

 

I installed the terminal screws in the mast today, and it was just like
described in the published instructions:
http://leoshoemaker.com/hexbeambyk4kio/broadhexstep3.html
It was a bit tricky at first but once I adjusted the screw holding
gadget I too installed all 10 screws in about 20 minutes. I used liquid
loktite on the screws as well as the lock washers.

Date: Wed, 09 Jul 2008

I just wanted to mention that the hole size I ended up with for the terminal screws on the center post were 7/32" rather than the 3/16" described in the instructions. Even after cleaning the paint out of the holes it was too hard (for me) to get the screws inserted from the inside. Once I made the holes a wee bit larger it went smoothly.

Date: Thu, 10 Jul 2008

The Kevlar cord arrived today. The parts list shows a requirement for
75 feet, and The Radio Works had it only in 200 foot spools. So I will
have 100 feet or so to sell to the next local builder. The price with
shipping was $31 for 200', so I will sell 100' for $15 if anyone local
is interested.

Today I also bought a bunch of 'S' hooks and some nylon cord to use with the initial shape adjustment.

( http://leoshoemaker.com/hexbeambyk4kio/broadhexstep5.html )

I will try to preserve the 12 sets needed so that future local builders
won't need to make up their own.

I put the hose clamps on the spreaders, and I think that some of the
diameters chosen are a little large. No matter, I can cut off the
excess with tin snips, but perhaps when it is all finished I will have a
better insight and may comment about that issue.

I built up the coax jumpers for the center post today.
( http://leoshoemaker.com/hexbeambyk4kio/broadhexstep3.html )
It was tricky to get the length right. In the end I think if I had cut
the coax to about 1/4" shorter than the distance between the element
screws it would have looked better. But it is fine the way it turned
out and I am happy with it. That liquid insulation is really messy, but
it is -very- neat stuff. I have plenty left and will happily share it
with future builders until it runs out.

I think I will add nuts now to the terminal screw to secure the coax
jumpers since there is plenty of screw length, and I can get them
cleaned and torqued down while inside in the air conditioning. There
will be enough threads left to make the actual antenna wire terminal
connections, and I will use conductive and corrosion preventative grease
to ensure a good connection. The parts list called for 20 of the 10-24
stainless nuts, I will add 10 more.

 

Finally, the yahoo site is a great place to visit, with G3TXQ posting
and responding. What a great time to be building a unique antenna, the
designers are all present and communicating!
( http://groups.yahoo.com/group/hex-beam/ )

Date: Sat, 12 Jul 2008

WoW! Fun morning!

The base plate fit on the center post perfectly, and W4DRM
( http://www.hexkit.com/ ) supplies a long and a short clamping set
screw with each mounting flange. The short set screw hold the center
post by compression, and the long set screw actually goes into the
center post to eliminate the chance of rotation and subsequent damage to
the center post. After marking the location for the long screws, I
drilled a 5/16" hole into the center post for each flange long screw.
Then I assembled the base plate on the post using removable thread-lock
on the set screws. I used caution on the short screws to not damage the
fiberglass post, I need to get a torque wrench!

 

 

The spreaders went on the base plate very easily, and the HexKit base
has holes pre-drilled for the 6-32 screws to keep the spreaders from
twisting and therefore galling. While the antenna was on the taller
test stand I drilled up from beneath the base plate in those pre-drilled
holes to make the proper clearance holes in the spreaders. It was a
snap and the screws are in place.


 
 
 
 
 

I spent part of the morning making up the temporary cords that I then
used to establish the frame shape. It was very satisfying seeing the
hex beam shape established. I put some liquid insulation goop on the
's' hooks where the nylon cord is attached to make it secure and to keep
the cord from unraveling or coming off of the hook. The cords with
hooks will be available for future local builders.

 

 

 

Date: Sun, 13 Jul 2008

I measured and prepared the driven and reflector wire elements. That
was tedious, took about three hours, but all is finished. I also built
up the tip separator cord and terminal block assemblies.
http://leoshoemaker.com/hexbeambyk4kio/broadhexstep4.html

In the photo of the 20M connector blocks you can see how I when I used
my band saw cut apart the terminal blocks, I preserved the terminal
block mounting holes for a handful of the blocks. I'm hoping that will
help with the 20M assembly in a manner similar to the plans, maybe a bit
neater?

Perhaps tomorrow I will install the wires and prepare to test the
antenna at about 5' high. Depends on the weather and my day-gig work
progress.

 

Date: Wed, 16 Jul 2008

Today I put the 20M wires in place and went through the routine of setting the required tip spacing and other distances. I used a 10' piece of emt tubing from Home Depot ($2.50) with a scrap piece of aluminum angle to make a 128 measuring stick. That sure helped!

I installed the wires in the morning, then fine tuned the adjustments in the afternoon, after the wind and sun hopefully un-kinked wire and cord to some extent. There were only slight modifications required, and I am satisfied with the results, it looks good.

 

 
 

Date: Fri, 18 Jul 2008

Today I have an 5 band HexBeam antenna!

I put the remaining wires on this morning, and adjusted everything in the afternoon. Then I attached the feed line and made preliminary measurements with the antenna ~ 3' above the ground. I am happy to say that the tuning seems to spot on, and the swr bandwidth curve seems to mimic the charts.

http://leoshoemaker.com/hexbeambyk4kio/broadhexswr.html

In general I have higher swr values. But not by much! I will test things more rigorously later when I raise the antenna on a higher test stand. Then I will see if adjustments are called for. The antenna will weather a few more days I expect before being hoisted onto the roof, and before the final mounting I will go around and be sure the tip spacing distances are holding up.

 

 
 

Date: Sat, 19 Jul 200

After our WCARES group breakfast meeting this morning I bought a 10'
piece of 1.25" emt pipe and raised the antenna up on it. It is still
near some telephone wires and a gutter, but it is well clear of the
ground. I re-measured the swr for the bands and was elated to see lower
numbers than from my previous measurement. For example now have lower swr across the 20 M band by 0.1 than the graphs posted by K4KIO: http://leoshoemaker.com/hexbeambyk4kio/broadhexswr.html

Other bands have also fallen in swr by one or two tenths, and are
in-line or lower than the graphs. This is -very-satisfying!
My sincere thanks to K4KIO for the site and plans, Max-Gain Systems for the fiberglass, and W4DRM for the HexKit baseplate and support.

I started by ordering parts on July 2, 2008, and I have been following instructions for assembly from this website:
http://leoshoemaker.com/hexbeambyk4kio/general.html

I ordered all the fiberglass poles and spreaders needed, incl. shipping:
$133.60 http://www.mgs4u.com/index.html

Baseplate and mounting components, incl. shipping: $146.26
http://www.hexkit.com/

(All prices at the time of purchase, some increases are to be expected.)

 

Date: Fri, 25 Jul 2008

Still no performance results, I just got it on the roof today!

Earlier this week I installed a roof mounted tripod, and to it I
attached a rotator and thrust bearing donated by WA4SCA.

Yesterday I installed a SO239 connector on the baseplate, and a balun
that I will discuss after performance testing.

Today I spent 4 hours dragging ladders around and using ropes and
pulley to haul the antenna to the roof. It really
was a blast figuring out how to do it and then it really was a breeze.
(Coulda used a breeze, the humidity was extremely high! Or maybe not,
probably it was a good thing the winds were calm...)

The antenna suffered no damage and it is now connected to coax into my
shack. I still need to run the rotator cable and adjust the azimuth.
The SWR bandwidth is the same as before or maybe even slightly better,
measured in the shack.

The baseplate of the antenna is 40' above the ground. I was going to
put it up on a 10' pole above the tripod, but I decided to wait and see
if I had to make modifications or adjustments first, so I went with a 5'
pole. The Traffie antenna is not supposed to be higher than 45' I
believe, but I don't recall similar specs for the broadbander.


Date: Sat, 26 Jul 2008

Ok Folks, this antenna is working as advertised and this will be my
final report. As a newcomer to Ham radio, I don't have the background
yet to evaluate this antenna against other directional antennas. But it
works just fine and according to the specifications. This antenna's base
plate is 40' above ground.

I have attached a PDF showing the SWR bandwidth for my antenna (blue
lines) as compared to that built by the author of the instructions K4KIO
http://leoshoemaker.com/hexbeambyk4kio/broadhexcomparison.html (red
lines). The antenna SWR was measured in my shack with roughly 50' of
LMR 400 coax feedline, using an MFJ-259B antenna analyzer. The blue is me, the red is K4KIO.

It appears that I have a close match to the calculated and exemplary
values, and I have very happy with the numbers. The 10M values are a
bit higher than I had measured before on the 10' pole in my front yard,
but still within acceptable limits. I may elevate the antenna a bit to
see if the 10M numbers improve, but I won't be doing that real soon.


Today I spent an hour or two monitoring signals on 20M, and turning the
beam to get a feel for the side and back rejection. I have never had a
beam in my short HAM experience, and I wasn't sure what to expect. In
many cases my G5RV dipole and the Hex Beam were equivalent in signal
strength when the beam was pointed in the signal direction. Never was
the Hex Beam weaker when pointed at the station. In most cases the Hex
Beam was at least 1 and usually 2~4 'S' points greater than the G5RV.
The front to back rejection was harder to judge due to the signal fading
and the time it took for the rotator to swing around. I'm guessing a
good 3 'S' points difference as an average.

 

 

Looking at the graph below comparing the classic Hex Beam vs this
broadband model,(blue=classic, red=broadband w/better F/B ratio), it is
apparent that this is not a highly directional beam as compared to a
multi-element yagi. But it does concentrate the signal in the forward
direction and offers side and back rejection to a greater degree than a
dipole or vertical.

I made a few Stateside contacts and got good signal reports, but I
didn't spend a lot of time with other operators comparing signals...yet.

I'm looking forward to more experimentation with this antenna, and at
this point I deem the construction project to be an unqualified success!

 
 
 

Date: Mon, 28 Jul 2008

In the last message I neglected to summarize the costs involved and
notes about the BALUN I used.

Attached is the expense list, the antenna cost me right at $500, but a
good deal of savings could be realized with better shopping for things
like the hardware. And I have half of a can of the liquid insulation
left, and 100' of Kevlar cord, and all of the temporary cords with hooks.

I really enjoyed the hand's on work, and I recommend it for anyone. It
was not hard at all. But if you are not inclined to do all of the
drilling and measuring, you can buy the kit for this antenna for $700,
( http://www.hexbeam.net/ ), but you will still need to glue it together
and paint it.

As I mentioned in my last report (final, ha!), the performance of the G5RV was as good as the Hex Beam for certain stations/directions. In order to keep this antenna's performance in perspective, below are few comments sent to me regarding my last report that I feel are worth sharing with those interested in this antenna:

1) From Leo Shoemaker, author of the plans:
> Dave:
> Congrats on the completed hex beam.
>
> I was pretty impressed with the correlation of your SWR with mine. I
> can't get measurements that close on two separate days with the same
> antenna!
>
> Your observation that this beam is not as directional as a full scale
> three element Yagi is certainly true. Some of the reviews of the hexbeam could make one wonder if it is a miracle antenna. I don't regard it as such. It is a two element compressed Yagi; nothing less,
> nothing more. Its beauty is the ease of tuning and compact size, etc. It will generally beat a dipole or G5RV simply because you can aim it whereas you cannot the fixed wire antenna. It's as simple as that and your quickie tests confirmed that. 73, Leo


2)--- In hex-beam@yahoogroups.com, Rick Denney <rick@...> wrote:
> Dave Matthews writes...
>
>> In many cases my G5RV dipole and the Hex Beam were equivalent
>> in signal strength when the beam was pointed in the signal direction.
>
> On 20 meters, the G5RV pattern is flower-shaped, with lobes projecting outward in a number of directions. In the middle of one of
> those lobes, the gain can be quite good. Of course, there are nulls between those lobes, where the antenna pays the piper.
>
> Another "of course" is that the G5RV happily fills your receiver with
> signals from all those other high-gain lobes, too.
>
> Your report suggests that the hex-beam is at least as good as the G5RV's high-gain lobes, but without the clutter caused by gain in those other directions. That's what a beam is all about.
>
> Your report also suggests that, when using the Hex-beam, I'll be able
> to put the tuner in bypass. There's no doing that with my G5RV. Rick, KR9D

Leo explains that this is not a magical antenna, and Rick reminded me
that the pattern of the G5RV is more complex than that of a simple
dipole, and that the beam bands are resonant....And then the guy who designed the antenna ties the ribbons on it:

3)From: Steve
To: hex-beam@yahoogroups.com
Sent: Monday, July 28, 2008 2:35 PM
Subject: [hex-beam] Re: My new G3TXQ antenna

> Rick makes a very good point.
>
> It's instructive to overlay the azimuth plot of a half-wave dipole
> onto the azimuth plot of something like a 102ft G5RV. As an example,
> on 10m the G5RV shows about 2.5dB peak gain over the dipole. But the
> lobe of the G5RV is so narrow that the half-wave dipole beats it on
> Gain for about 60% of the total azimuth. So unless your operating is
> confined to a few particular directions, and your G5RV happens to be
> orientated the right way (and remember, the lobes point different ways
> at different frequencies), a half wave dipole could be a better option.
>
> At the end of the day, the ability of a beam like the Hex to point the
> energy where you want it, and to reject signals from other directions,
> is a massive "plus", even if the Forward Gain is not great.
>
> 73,
> Steve G3TXQ