How close can I install the OCF DX Flagpole to my home?

by Greyline Performance 10月 29, 2018

Hello Friends and Peers!

Many have asked, "how close can I install the antenna to trees" or "my home" and "surrounding buildings" so we asked antenna designer and engineer, John Portune.

He came back with a worst-case scenario for us by calculating an OCF Flagpole near metal siding!

John's findings are encouraging indeed. What can you learn from John's experiment? Read his notes below and let us know your thoughts too!

TU and 73

Does it matter where you mount the pole?

By John Portune (October 29, 2018)

My existing 20 ft. flagpole (4+16 ft. 2 in. aluminum, 1 ft. fiberglass base insulator and 4 in. fiberglass feed point insulator spacing) sits roughly 18 in. from my metal-skinned mobile home. I added a new mount 15 ft. away from the house.

In both locations, I used my VNA to measure the impedance and SWR's at the input of the 5 ft. 450 Ohm ladder line from the base to the feedpoint in three situations.

(1) near the house with a flag,
(2) away from the house with flag and
(3) away from the house without a flag.

The graph below shows the SWR vs. frequency.

Clearly, the flag has no effect, the two curves, with and without a flag, totally overlap. From 40m and up, the house has only a little effect. On 80m the house increases the SWR. (

I also measured the impedances but did not plot them on this chart. The R is very much the same for all bands. The reactance (X) follows the SWR. These are not surprising.

I think these measurements show that the user does not need to pay much attention to where he mounts the pole. My metal-skin house is pretty much a worst-case scenario. However, very close to a large metal building may make it difficult for an auto-tuner to tune on 80m.

Lesson: Install the pole more than 18" inches away from your metal siding house. (worst case scenario, right?) 15' is certainly far enough away to lose interaction. Have a home made of a material other than conductive metal siding, such as stucco or wood? Install your antenna less than 15' and more than 18" from the home for best results.

Thanks, John! Hope you learned a little something here. I sure did. Looking for just a little more confidence to get you and your friends back on the air?

- Greyline Performance Team

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Thanks John for working this out. I’m sure it will help a lot of op’s to decide where to put there flagpole when they purchase one. When I bought mine, really didn’t give it much thought, though I probly should have, hi hi. Mine is about 8 feet from my porch and it works great.

Nuff said, thanks again.

Best regards and 7 3’s

Larry Ward W7GST

Larry D Ward W7GST 11月 08, 2018

24' Flagpole does the job.

I purchase a 20’ Flagpole antenna that also included the 4’ extension. I installed the flagpole the end of January here at my home in central Florida. The install was easy with only a couple of small issues that were easily resolved by just thinking things through. I installed the antenna in the back yard in the HOA and have not had any complaints.

The performance of the antenna has been very good. The SWR on most band has been =< 1.5 except the 12 meter band. The SWR is just under 2.0. The DX into Europe and Africa has been good. Have done a lot of FT4 and FT8 with good reports. SSB has been good with good signal reports depending on propagation. All of my contacts have been made on 70 – 100 watts. I am using a SGC 230 tuner mounted at the base of the antenna

Most of my contacts have been 10 MHz – 28 MHZ. I have done some work on 40 meters but not much. Not much of an night owl so I don’t get very much of a change to use the antenna on 40 – 160 meters. The SWR is on these bands is 1.0 – 1.3, so I would expect good performance if I had more power.

At this point in time the only negative I have to report is the flag. It has been flying on most days in 5 to 15 MPH winds. I have taken it down when we had higher winds had exceed the 15 MHP. I noticed this morning the flag was torn and shredded. I took the flag down and noticed the flag was made by Anley and it was manufactured in China. I wouldn’t expect a flag to be in this condition after 3 months. I had USA made flags last over a year flying in much stronger winds that this one.

I'm only giving a 4 because of the flag issue. I will reach out to Greyline to see what they have to say.

We are so glad to hear that your Antenna has FB SWRs from 160-10M and congrats on the great DX! Fun... We buy our flags from several USA companies one of which is Anley, Inc., which is also a US company based in California. We are happy to replace the flag.

US GOV reports 90-days is the expected Flag lifespan. 'The U.S. Government generally expects a nylon or cotton flag to last 90 days based on being flown daily from sunrise to sunset - but not during periods of inclement weather. Tests have shown that, in some cases, a flag flown 24 hours a day will last only one-fourth as long as one flown only during the daylight hours.' - again, happy to help and we will contact you directly for a replacement.

Remember, Ham Radio is fun again, Please pass it on to your friends and family. - 73m Greyline Performance

Thank you so much!!!

It has taken me a while to get it put together and up, but with the help and patience of two of my sons, my beautiful flag pole antenna is up and operational. I am still learning how to use my radio, just found out my microphone has an on/off switch for example. The install is complete but it is working already. I will send some pictures. I am thinking about a 4' extension for my 16' flagpole antenna. Does the extension go on the bottom? If it does, i may do that.

IMPRESSIVE IMPROVEMENT

This is an antenna I wish I would have purchased sooner. We live in an HOA with a small lot and some restrictions on antenna placement and height. We had a small vertical antenna mounted to our fence, but had limited places to install grounds and could only put two in place along the fence line. We could only receive 40M, sometimes 20M, and both had to be tuned and adjusted at the antenna. This year, those bands began generating high SWR. I was able to determine the wiring and connections were all good but the antenna was failing and we would miss out on the new solar cycle. We ordered a 20' Greyline, without the flag mount options, along with an LDG 100W external tuner. Due to a backlog in supplies, it took many months to process my order, and when I paid with a credit card it was cancelled the following month because they could not ship it within 30 days to process my credit card. I called and they no longer had any 20' antenna packages to ship at that time, but they agreed to ship me a 24' for the same price without further delay. That was still not going to be visible from the street above my home which is an HOA requirement, so I agreed. After receiving the equipment and installing it, I was amazed. 40M, 20M, 12M, and 10M bands were all below 1.5 SWR. 30M was an impressive 1.1 SWR. Unfortunately, I could not tune 80M, 17M, or 15M due to high SWR. Quite possibly this is an issue with the LDG tuner. We have reached far away with this antenna, and my wife began using FT8 and collected QSOs with 29 countries on multiple bands within a week. I was able to reach Australia, which showed a distance of 10,000 miles. The antenna is in my back yard, close to my house and neighbors say they don't notice it. While I could have installed it in the front as a flagpole, I would have to re-rout all of my wiring to the front of the house. This is an impressive antenna. If I were to do this again, I would like to have purchased an already assembled ladder-line to PL-259 adaptor as assembling the provided kit proved somewhat challenging without a drill press which I no longer have after downsizing a few years ago, and having to modify the clamshell case so that it would fit over the PL-259 component. The RF-choke required weather proofing so I ended up purchasing 1-1/2" waterproofed shrink tube that seemed expensive for the length needed. In the end, it all worked well when connected. I fully recommend this antenna.

Wow! So great to hear that you and the XYL both are enjoying the bands together. Let's get those other bands working. Likely a ground issue we can resolve. *We've already called him for a few testing exercises to get things dialed in. Ham Radio is fun again! Pass it on... 73 Greyline Performance

Proudly displaying "Old Glory" and working the world!

At the age of 79 was able to install the 20ft flagpole antenna without help, which surprised me. I installed solar lights above and below the flag and it's a beautiful sight at night. I attached the ladder line directly to the ground and long wire terminals on the MFJ tuner and it works perfectly. Very low SWR on all bands. In spite of poor band conditions I have been having a blast. Frankly, it tickles me to have my antenna sticking up in my front yard in plain site. My neighbors love it and the HOA is clueless. 73's, Kelly K4SLE

Latest review

Band conditions have been tough running barefoot, but I have been working DX on 20 meters! DL, SM, YU, RU, ZS, TI all in a single morning with only 70 watts. In fact i have had so much fun being back on the air i have made the decision to replace my aging 30+ year old Kenwood with a new radio. I been pleased with the antenna and my neighbors have been pleased with the look of the flagpole.

How close can I install the OCF DX Flagpole to my home?

Does it matter where you mount the pole?

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