Category Archives for "Antennas"

Weekend fun…

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A little weekend fun…

A tower with stacked beams and a foursquare fell in love and decided to get married.

The wedding sucked.

But the reception was INCREDIBLE.

Would your government give you a permit for this tower?

OH8X 160/80 Tower and AntennasI really love the hams from OH. They think big, think tall, and look for the most out of their antennas. Since they get hit too often with all that aurora stuff, they try and compensate with bigger, stronger, and better antennas.

If you are in a low point of the solar cycle, build bigger and better antennas for the lowbands.

Like this announcement from OH8X:

It’s well known that the bigger and higher the antenna, the better results you’ll get. The new 3-element 160m antenna at OH8X must be about as big as you can get. Look out for a strong signal from them during 2009.The new antenna for the 160m Amateur Radio band was completed just in time for Christmas on 24th December after OH8SR and OH6RM had spent three weeks installing it.The Arcala Extremes station OH8X is located at Arkala 65.18N, 26.24E.

The specs? 100 meter tall tower (not feet, but meters). 60 meter booms for both 80 and 160 meters. and five 80-meter full size elements.

You can see the picture on the Facebook site.

Would your local government provide you permits to put up this antenna support structure?

Me neither. But it sure looks nice!

The effect of ice on antennas

Aglow in the SnowEngineering can only take us so far. Mother Nature knows all about engineering and creates havoc with the best sites and the most careful owners.

Take out the power and one is left with generators and a mess.

K1TTT’s great site is an example of excellent engineering meeting the power of Mother Nature. David’s documented it on his web site. Well worth the look.

David — best to you in getting it all back together. What a ton of work.

Antennas for 100-pound DXpeditions

image One of my favorite ham radio web sites was 100 pound DXpedition, a look at what it takes to organize and execute a light weight DXpedition. Unfortunately, Scott, NE1RD, decided he had written all he needed to write about the subject for his blog back in November, 2007.

But he hasn’t stopped writing.

Scott’s latest foray is to take all of the experience from his DXpeditions and write about the antennas used and tested. He’s initially published this report on the web. But, it also looks like he’s going to be publishing it in a couple of different formats, available for download as well.

The most encouraging sign: this is volume ONE.

Can’t wait for the rest.

Scot, K9JY

Still liking ZeroFive Antenna

Got a note late yesterday asking whether or not I was still liking my ZeroFive Vertical that I put up earlier in the summer.

The short answer is “yes.”

Great construction, good instructions, and good performance. The antenna has been used in Field Day (with a comparison to another local Field Day site), the IARU Contest, and working PSK31 on the air.

I spent a lot of time getting 60-radials set up with the system, including crawling around under my deck laying out wires. What fun – but worth it. The radials, combined with the superior construction done by ZeroFive Antennas is what makes this antenna a great performer.

The original series of articles on the project are all here on the K9JY site: The Project, Preparation, Installation, Radial Installation and Performance. You can also check out the pictures on my photo site.

Scot, K9JY

Blowing up a tower or four

The Naval Academy has a transmitting site for Very Low Frequency communications with submarines.

Or, had.

The 31-second video has the take down. There is a guy who says “happy new year” on the video, but it was just added to You Tube two days ago. You can also see more about the site from a ham tour of the facility.

Hat tip to TowerTalk reflector, W3LPL, and Peter for the links.

Greenbury Point Towers Demolition: Naval Academy Annapolis, Maryland.

httpv://www.youtube.com/watch?v=qdvpjV1Mb1w

ZeroFive Antenna — Performance

image After prepping the parts, installing the antenna, and installing the radials, we finally get to performance of the 40-10 meter vertical from ZeroFive Antennas.

The antenna is designed to work with a tuner. In my case, I use the built-in tuner on the Yaesu FT-1000MP.

SWR is more than acceptable with the tuner.

Radials make a difference in SWR

I installed some radials and then measured the SWR. Each time I installed more radials, the SWR was different.

Here’s what it looked like:

Frequency   30-radials   45-radials   60-radials
7.000   2.50   1.80   1.80
7.300   2.75   2.00   2.00
             
10.100   2.75   2.80   2.80
10.150   2.60   2.80   2.80
             
14.000   1.80   1.90   2.00
14.350   2.00   2.00   2.00
             
18.068   1.70   1.70   1.80
18.168   1.80   1.90   1.70
             
21.000   2.10   2.50   2.50
21.450   1.50   1.90   1.70
             
24.890   1.60   1.50   1.30
24.990   1.60   1.60   1.20
             
28.000   1.30   1.50   1.40
28.300   1.20   1.40   1.30
28.600   1.20   1.40   1.20
29.000   1.20   1.30   1.20

 

As I mentioned, these SWR ranges are easily handled by my tuner.

On-the-air

I have not made hundreds of contacts yet with this antenna, so early on performance can’t be based upon experience. That may change this weekend with Field Day; we shall see.

However, I can say that this antenna works what it hears. There have been enough contacts that were tough for me to hear where the other person was copying me Q5, regardless of signal strength. I attribute that to the radials and the path of the radiated signal from the vertical.

Consequently, I very pleased with the results. ZeroFive puts out some killer antennas; the construction of the hardware is first-rate. You will note how small a profile this antenna makes; ZeroFive just added a “flagpole” line of antennas — with flags!

Plus, the single band antennas would make a great four-square or other type of vertical gained antenna.

I’d highly recommend ZeroFive Antennas for both their product and their service.

You can see all the pictures at SmugMug.

Scot, K9JY

ZeroFive Antenna — Radial Installation

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After getting the parts organized for the 40-10 ZeroFive antenna and installing it on the mounting pipe, it was time for installing the radials.

Radials are critical to the performance of any vertical. Most hams put far too few radials under their vertical antenna to have it perform the way verticals do. They let half the signal go into ground because of the lack of radials.

When I lived in Madison, WI, I built a vertical for 40-meters. At the time, I lived in a city lot with a chain link fence around it. I literally put 60-radials around the antenna to the chain link fence. I also connected a radial to the ground system for the tower.

It was killer.

I didn’t care if you had a 3-element  beam on 40-meters. I got in the middle of the pile-up with confidence that my antenna would perform like gangbusters. And it did.

I helped another ham who had a 2-element beam for 80-meters up 120-feet and a full quarter-wave 80-meter vertical. But no radials under the vertical. So, of course, the 80-meter beam worked better.

Then we put down a radial plate and 60-radials of 66-feet each for the band. From that point on, if anyone could be worked on 80-meters, the vertical was the antenna that got the contact. (DX, of course).

Radials are necessary for turning your vertical into a great antenna.

In my experience, a lot of radials under your vertical also make your vertical much quieter. This is because so much wire so close to ground  causes the receiving to have a beverage effect: much quieter.

And more wire gives your vertical a perfect launch for your transmitting signal.

Radials are a pain to put down. But necessary.

It took two full days to put down 60-radials. You can see from the picture above that I have large bushes and/or trees to get through with wire. Plus a great deck — one that I crawled under to install ten radials.

The original plan was to have sixty 24-foot radials, but I ended up with some over and under that length. When I could run them longer than 24-feet, I did, especially under the deck and to the left down my lot from the picture perspective. About five of the radials are about 50-feet in length.

You can see all of the pictures at SmugMug.

Next up: performance, including SWR.

Scot, K9JY

ZeroFive Antenna Installation

image After receiving all of the parts and getting them in order, it was finally time to do the installation of the ZeroFive 40-10 vertical.

Digging the hole

As a reminder, the first piece done was digging the hole for the cement and the mounting pipe. In the Puget Sound area of the Pacific Northwest, this is no easy task. Puget Sound was formed from glaciers in the last ice age and what is left is mostly small rocks with some dirt around them. Hand digging takes time.

However, I was able to get down almost to the recommended depth and was able to mold the hole into a bit of a bell shape at the bottom so cement would need to come up against earth.

After that came putting the mounting pipe into the ground. I then used levels to get the pipe perfectly vertical. I then used stakes and rope around the pipe to hold the pipe in place to maintain the vertical before pouring in the cement.

After the cement is in place, you wait for it to cure.

Mounting the antenna

Finally, we get to the day where the antenna gets mounted to the mounting pipe.

First, one needs to put the radial plate over the mounting pipe to the ground. After that comes the antenna.

Here’s a picture of what each of the 3-foot sections, all perfectly tapered to fit into only the correct aluminum tubing section:

image

This picture is slightly out of focus. There are two items to notice. First, the tube is slit in three places around the end of the tube to aid in fitting the sections together. Second, the stainless hose clamp used to connect the sections together.

Each section is marked before shipment with a line for fitting to the section so you get the correct length. No need to measure on your part; a great time-saver by ZeroFive.

I put on connectivity goop on each aluminum section; the inside of the tubing shown and the outside of the connecting tubing. I did this for each section.

The top section comes with a black cover for the top section of aluminum tubing. It was not cheap and fit tightly into the tubing. This, of course, to keep rain and snow out of the vertical.

And, from our first article, remember that above the insulator there is also a weep hole drilled into the aluminum tubing for condensation that may build up onside the aluminum tubing. Very smart.

The fold-over mounting plate is then attached to the mounting tube. I then attached one 12-foot section to the mounting plate and then another 12-foot section to that so the entire vertical was connected, but on the ground. The 12-foot sections were easy to carry from inside to the antenna; your situation could be different. Each section of the antenna is 3-feet long so you can connect the length you need to carry around as needed.

Then I slowly walked the entire antenna up so that it was vertical, tightened down the number 8 bolts to secure the antenna.

Staring at the antenna

Then I stared at it for a while. Always nice to see an antenna…

After this, I installed the Balun on the ground side of the antenna and connected the center and ground from the Balun to the correct bolts.

Finally, for that day, I connected the coax to the Balun and ran the coax back to the house. Turned on the radio, of course, and heard signals.

Radials were left to two full days to come.

You can see all the pictures at SmugMug, where I have all my photos (still uploading more galleries to this great site from the laptop).

Next up: radials.

Scot, K9JY

ZeroFive Antenna Preparation

Earlier this year, I hinted at a new antenna project that I would be doing. Well, it’s finally done. Everything takes longer to do than expected, right?

After ordering the 40-10 ZeroFive antenna, Balun, coax, I left them in their boxes for a couple of weeks or more. Then, I started to get the pieces out of the boxes. These people make great hardware!

First, I dug a hole and purchased the mounting pipe. I also bought 1500-feet of number fourteen insulated copper wire to be used for radials.

After digging the hole and mounting the pipe in the cement, the unwrapping began.

Here’s a look down the mounting hardware:

image

The left side of this photo is where the in-ground pipe will attach to this plate. The right is the install plate for the antenna.

Note the number 8 bolts that hold the antenna in place. Removing the top one allows the entire antenna to be walked up and down for work. Also note the green insulator at the back of the pipe. High quality, precision machined. Just above the insulator is a small hole for moisture to leave the pipe — a great touch.

Here’s a different view of the hardware:

image

This configuration makes it extremely simple to install the antenna on the mounting pipe. I had no problems installing this by myself.

The top of the picture also shows the aluminum tubing in their bubble-wrapped shipping form. The packing for the parts for shipment was way beyond normal.

Here’s a view of the radial plate and bolts for the plate:

image

This radial plate holds 60-bolts (comes with the plate). It is designed to be installed around a 4×4 inch post, or to be connected to the mounting pipe with a supplied U-bolt. The two round holes are designed for ground rods (which I did not use as they would have hit the cement).

Next is the installation plate for the Balun.

image

The four bolts fit the recommended Balun perfectly. The other two holes are for the U-bolt (supplied) to connect to the antenna.

The Balun is designed for mounting on a beam. Consequently, the weep holes for moisture are not open to earth. The manual recommends, and I followed, sealing the holes and drilling new ones on the side of the Balun facing ground.

Finally, here is the insulator between the antenna and the ground portion of the antenna:

image

The two bolts are where the Balun wires connect. The Balun manual notes which side is the center and which is ground.

The only engineering comment on this great antenna was that both bolts were facing the same direction. There wasn’t enough wire supplied between the Balun and the antenna connections here.

What I did was remove and reinstall one of the bolts shown, but in the opposite direction. By doing this I had wire for the “nut” side of each bolt for connection. It was a long haul, too. The bolts are machined through the insulator.

That was the setup. Next, I’ll cover installation.

You can see these pictures and others on my picture site. Simply put your cursor inside the main photo and you’ll get a menu of sizes to look at.

Scot, K9JY