Tag: EXPERIMENT

From the Desks of Mike Pickett W9MWP and Steve Purshock KQ4SMM

Several years ago when I started visiting Fort Walton Beach for long periods of time after retirement I deiced to erect an antenna in the back yard of my hosts Cheryl and Steve KQ4SMM. When at home I regularly check in to the Badger Weather Net on 3.984 MHz. and decided it would be great if I could occasionally check in with warm numbers while visiting Florida. I started out with a copy of the antenna I use at home which is known as “The Mystery Antenna” a variation on the G5RV, a multi band antenna with peak performance on 20 meters. Details on that antenna can be easily found on the internet by just simply searching for “mystery antenna”. This antenna worked sometimes and sometimes not as is common with HF and propagation. I decided to look for something else a little more reliable and settled on an 80 M loop antenna mostly because it is often praised as a quiet antenna and void of noise.

Construction

The first step in any project is to sit down with pencil and paper and a calculator and draw out a sketch to see if the project is workable. I started with the calculation to determine the full wave length of the center of the band 3.750 MHz. L=1005/F MHz. The result of that calculation was 268 feet, divide that by 4 and it comes out to 67 feet on each side, a quick jaunt around the back yard with a 100 foot tape determined I could easily do a 67 foot square in the space provided. Steve already had 2 ten foot sections of chain link fence top rail screwed to his fence forming a 20 foot mast for his VHF antenna with a rope and pulley on top. He had provided a duplicate mast for me to launch my Mystery Antenna for the last two years which now provided two of the for masts needed for my project, so it was off to Home Depot to acquire 4 more sections to complete my square.

Supporting masts attached to fence in the back yard

After drilling and attaching 1/4” eye bolts and pulleys to the top of the two new 20 foot masts we screwed them to the fence on the other side of the property and awaited for the wire to arrive from Amazon, which is another disappointing story I won’t get into. Because the masts were not counter guyed against the strain of the antenna wire I chose light 18 ga. magnet wire for the antenna radiator so that it didn’t put excessive strain on the masts and would be easy to pull through the insulators on top of each mast. The plan worked well and once I had the wire I could easily string in through the insulators on each mast on the ground and we pulled the antenna up a little at a time until I felt the mast had reached it’s stress point. I purposely positioned the masts further apart then necessary to deploy the antenna so that there would be a little extra rope on each corner keeping the insulator away from the mast.

Testing

Connection to the antenna was a SO 239 soldered to each side of the insulator located in the corner near my operating point. After running the RG 8X into the shack I took a reading with my antenna analyzer and found the SWR null to be around the 3.650 MHz. somewhat lower than my target and measured about 1.7 to 1. Connection to my Kenwood TS 570S showed a different scenario however with the SWR off the scale everywhere without the tuner on. I found I was able to get the SWR manageable and down to 1.3 with the tuner. I attributed this to the direct connection without the use of an un-un Oh well too late in the day to make any more changes so I put it to bed for the day and decided to try for the Weather Net tomorrow.

Modifications

I was able to make contact with the Weather Net even with the antenna not showing the results I had intended. Now it was on to make the necessary modifications to make the antenna perform as intended. With the SWR graph null lower in frequency than target I knew the wire was too long so trimming was necessary. Taking into account how far it was off target and the ratio of the calculation for length I decided 15 feet would have to come off to get to 3.750, I cut 12 feet off thinking I can always cut more should my calculation be wrong. It came out to be about 3.7 MHz. Center so I was pretty close. While trimming for length I also installed an unun I had in my antenna box at the feed point and after a little modifying of the enclosure and adding a couple of terminals I was able to connect the aforementioned unun with a couple of wire nuts that were living in the pocket of my jacket. I would suggest soldering the connection for a permanent installation however. After examining the null on the analyzer graph though I found that it was not wide enough to cover the whole band with a decent SWR and maybe was 150 kc. on each side of center that was acceptable SWR with out the tuner. Since I was looking for the best performance on 3.984 MHz. I decided to cut another 10 feet off the radiator which brought the graph null in range at just under 4 MHz. I measured an SWR of 1.99:1 at 3.984 the target frequency, close enough I figured for a temporary antenna.

The extra un-un laying around in my antenna box

End Result

The next morning I was on with the folks from the Badger Weather Net and we were able to hear each other direct, reports from the net resulted in mostly somewhat weak but able to copy with generally a 5-6 S meter reading while using my Kenwood TS 570S with 100 W. While the antenna is not perfect it gets the job done and is reliable which is all I could ask for. I still am able send Winlink messages on the other end of the band with the aid of the radio’s built in tuner so it’s a usable antenna across the band with the aid of a tuner. Many people consider the loop antenna to be a much quieter antenna than a conventional dipole. I cannot attest to that since there seems to be a high noise level on 80 M here at Cheryl and Steve’s house. Overall I felt this to be a fun and rewarding project that accomplished my goal and provided some useful information and antenna building experience for Steve and myself.

Respectfully submitted by Mike Pickett W9MWP and Steve Purshock KQ4SMM

“What are you working on?” From the Desk of K4LWM

By DJ Stewart

On March 8, 2026

In Announcement, Pile-Up, Technical

A very common question at any of the Playground Amateur Radio Club meetings, pile-ups or importune events is “What are you working on?”

It seems to come from any member, because everyone is looking for something interesting, potentially for their next project. I have even asked that question, of other members, when I hear snippets of conversation that pique my interest.

In the past year I have been asked the question several times and have not really had a good project to talk about. Not because I have not been busy or not looking for things that I wanted to work on, but mainly because I have been listening and taking notes and investigating, that is if you consider watching YouTube videos investigating. Yes, I have been looking for what I want my HAM radio experience to be.

Let me digress, I have had my license for over 25 years, but I came from a club in Birmingham that was very active in the weather warning scene. The club (BARC) had networked repeaters that covered the entire five county area that made up the Birmingham metro area. Lots of members that were active on the VHF bands at all hours of the day and night. I was content to be just one of the members and because of a job that kept me mobile most of the time, I was one of the Ratchet Jaw operators you found on the bands during the normal work day.

In 2013 I purchased a home in FWB to serve as a vacation home with the intent to retire there or at least in the area in the future. While I was working on the house trying to get it ready for that retirement day, I monitored the bands but was very disappointed because of the lack of traffic. I did make a few contacts and enjoyed having breakfast with a few of the operators that I met on the local repeater. Those were few and far between because I was still traveling back and forth to Birmingham for work. Of course, the restaurant, Mother Earth, closed and I lost contact with the few HAMs that I knew from this area.

When I retired in 2017 and moved to FWB full time I had lost interest in Amateur Radio and to downsize I sold my tower and all most all of my gear. I thought this area was void of radio activity. Unfortunately, I had just not met the right people.

All of that changed when I connected with Bill, KQ4ATC, which lead to an invite to PARC’s field day, where I meet several operators and had a very good time. That activity earned an invite to Tech Night at the PARC club house and then to membership and then to that question, What are you working on? I did not really have a project to talk about.

That led me to ask myself, What do I want my HAM experience to be?

I became an active participant in the club, attended tech night, the business meetings and the swampfest, along with other club activities. I found that my interest in Amateur Radio was renewed and I started looking for what I wanted to do to enjoy this hobby.

I dusted off the old Icom IC 7000, built a LiFePo4 battery box, purchased a wolf river coil vertical antenna and started making contacts on 20 meters (chasing POTA) something that I had never done in the past. That was fun but, hearing the other club members discuss the projects that they were working on still left me with a feeling that I was not really embracing the experience yet.

Other members were creating things with 3D printers, experimenting with an assortment of antenna, incorporating digital modes of operating and then trying to bring the information to the club members at tech night. Wow, what a varied assortment of activities they were involved in. I started making notes in my little black book. I made list of components that were used in the various projects, websites for sources of the components and/or YouTube videos describing similar projects.

I would take my list to the hamfests, tailgates or swap meets that I attended. I ordered torriods, enameled wire, printed project boxes and began to build transformers, balum, ununs and chokes. By collecting the various parts and pieces an idea of a project that would allow me to expand my radio experience formulated in my mind. I wanted to build an antenna that would allow operation on the low bands that would work within the confines of my lot size and the HOA restrictions.

I assembled an antenna mast out of chain link fence gate post, used push-up antenna mast and 1” Lowe’s PVC pipe that combined to form a 30-foot base for an EFHW 40-10-meter antenna. This was installed in the back yard next to my storage shed. The 20-foot flag pole in the front yard anchored the other end of the 63.5-foot 18-gauge EFHW wire. This arrangement did fit into the 38×150 foot lot size of my property and kept the antenna wire behind the front of the house.

The tuning process required raising and lowering the wire many times pulse adding a counterpoise and trying to compensate for the metal roof on the shed which is under the feed point of the antenna. Finally, after two days of tuning, an acceptable antenna SWR was achieved for the 40-10-meter bands and the IC 7000 was hooked to the coax and powered on. When the 40-meter band was selected the radio came alive with Net traffic at 7.185 LSB.

I was able to join the net and made 35 contacts on 40-meters, which I had never operated on before. Those contacts ranged from Wisconsin to Connecticut down the east coast to Virginia and even one in ST Augustine Florida, all within 20 minutes. I was operating mobile from a patio table on my deck, on an antenna that I built. This was quite an accomplishment for my first project build, made possible by the influence from the members of Playground Amateur Radio Club that renewed my interest in the core activities embraced by the HAM radio community, Experimentation and Implantation.

So, can I ask you, “What project are you working on?”