Tag Archives: 6m antenna

ARRL June VHF Contest

For the first time I had a functioning 6m station for the ARRL VHF contest. I used the Par Electronics Omni in its temporary location and my Kenwood TS-480SAT.

The contest started at 1800 UTC Saturday 11 June. I was a bit late for the start getting my first contact, W9GA in EN53 at 18:55 UTC. This was followed by three more stations in Wisconsin and then the band opened up for me and I could here more stations. For awhile after that I was getting a new station about every five minutes, scanning the SSB portion of the band. All my signal reports were good.

My XYL arrived home from work and wanted to go for dinner at our favorite BBQ place, Altas BBQ. Talk about the horns of a dilemma…XYL and Atlas BBQ…VHF contest…XYL and Atlas BBQ…VHF contest…hmm, what should I do? Actually it wasn’t that hard even though I am enjoying 6 meters. So after an excellent Cuban sandwich (I heard it’s good for propagation) I returned to the contest and had 26 contacts when I pulled the hook at 0259 UTC.

Extents of contacts

Most distant contacts

I had a wee bit of time to grab a few more stations on Sunday morning. In the end I contacted 33 stations including my first DX station, VE1PZ in Nova Scotia. This brings my grid total to 29 and 14 states on 6m. I really like 6m operation. The dynamics of the band are very interesting in a way that is much different from that of the HF bands. I guess that’s why it’s called the magic band. I’ll be watching for more openings and hope for a big opening to Europe.

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Par Omni – Initial test

Yes, it’s time for the latest installment of Tim’s 6m adventure. This one begins where the previous post left-off, the the Par Omni. My nice new OA-50 leaned against a workbench in my shack all week waiting to go outside and play with all the other antennas. Well Friday was the day. I stuck in on the aforementioned mast that I used to test my Par Moxon and bungee corded it to the side door of the garage workshop.

Par Omni @ 20ft

Par Omni @ 20ft

The wire in the picture is not a powerline, it’s one leg of my Cobra UltraLite Junior. It was temporarily deployed late last fall in order to have a backup for the winter in case my main antenna came down which it had the previous year during a very cold period late in January. Typical antenna behavior. They never have problems when it’s sunny and 72.

A quick test with my MFJ-259B showed that the SWR was at 1.1 at 50.125 and thru the SSB portion of the band. Using my TS-480SAT I slowly scanned through the range from 50.125 to 50.200 and didn’t hear anything. I returned to 50.125 and called CQ a few times to no avail. So I flipped back to 20m and worked some DX and NPOTA stations, occasionally checking back to 50.125 and watching DXMaps for signs of band activity.

On one of my checks I heard Ray, K9KHW and responded to his call. Being new to 6m operations I asked Ray about the tools that are typically used to check on 6m activity and he recommended the DXMaps site and also subscribing to the ON4KST chat which I subsequently did. He also recommended checking activity later in the evening. The rest of the afternoon was spent on HF.

About 7:30 PM CDT band activity appeared to be increasing as indicated by  the DXMaps site. Hearing nothing on 50.125 I called CQ with no response so I moved to 50.130 and called CQ and Kevin, W9APE in Sheboygan responded. With only 38 miles between our stations we certainly weren’t pressing the limits of the 6m band but he was very helpful with a few more 6m operation questions that I had. Shortly after breaking with Kevin to tune around a bit a station from Houston, Rick K5GZR called him followed quickly by another station in Houston, Dan N5TM. I could hear the two Houston stations very well so after W9APE completed his contacts with them I gave K5GZR a call and he responded with a good signal report. After a nice conversation with Rick I called for N5TM and he responded as well with a good signal report. Both of these stations had much more substantial antenna systems than my Omni on a pipe and also power but I was able to clearly hear them (no real surprise) and more importantly they were able to clearly hear me. That’s a thousand miles on 6m with an Omni on a pipe at 20 feet and 100 watts. As I think of it I should have tried to reduce power to see how low I could have gone and still maintained contact. After breaking with Rick and Dan I tuned around a bit more and called CQ on occasion with no response. I heard KI4FCQ in Georgia on 50.125 and called for him, while he had my call we were not able to complete the contact. I returned to 50.130 and called CQ again and Matt, W3UUM responded. Matt is located well east of Houston so another 1000 miles on 6m. As a side note you should check the picture of Matt’s antenna farm on his QRZ page. It’s very nice and enough to give the average HOA president a well deserved heart attack. After a nice contact with Matt I called CQ one last time as weather radar indicated that a storm was approaching and would be at my location in less than an hour. Bruce, W9XX responded and after a short contact we both decided to pull the hook in the face of the impending storm as Bruce is located in Sheboygan and the path of the storm was angled such that the leading edge of the storm was closer to him than to me at that point.

All in all a successful day of 6m operations. The Par Omni performed as expected and given that this is the weekend for the ARRL June VHF Contest it will get a bit more workout if the band conditions allow. Plus my XYL thought the Omni looked cool which I’m certain is wife-speak for “Honey, why don’t you get some more antennas.

Conclusion: Par Electronic’s antennas work very well and 6m is a blast!

Update: Here’s an interview with Dale Parfitt of Par Electronics

Update: Here’s a nicely done introduction to 6m operation that’s largely done on air with KF7ETX.

More Par to ya

Briscoe Darling couldn’t have said it better. Based upon my experience with the Par Electronics Stressed Moxon I decided to get more Par…Par Electronics that is. The Moxon was intended for my portable station but I also wanted a fixed 6m antenna. So the obvious solution was to get another antenna! As with the Par Moxon, I’ve wanted one of Par’s Omni’s for quite awhile as well. Since I bought the Moxon used and saved a fair amount of money over the price of a new one I figured that buying a new Omni would save even more, at least that’s what I told my XYL. Besides, it works for her, “Look honey, if I spent over $100 then they gave me an additional X% off so I saved $Y.” You have to spend more to save more, isn’t that how it works?

In any event, I sent Par Electronics an email inquiring about the price and shipping for an OA-50. I received a very prompt reply (I sent my message at 8:51 PM on a Tuesday night and got a reply 22 minutes later) from the owner, Dale Parfitt with all the information I asked for plus more including the fact that they were about 3 days behind on orders and working 80+ hours a week to keep up. I guess that’s a good problem to have if you are a small business. I was in no hurry as long as I had an order in the queue. I figured that I’d see it in a couple of weeks. Based upon the eHam reviews it was definitely going to be worth the wait.

Six days later Brown Santa dropped off a package:

What's in the box?

What’s in the box?

Opening revealed the brand new OA-50:

OA-50

OA-50

A quick inspection showed everything intact even though the box was a bit roughed up. The quality of all the parts is the typical top notch that you’d expect from Par Electronics:

OA-50 parts

OA-50 parts

One odd part was this:

Has Par nailed it?

Has Par nailed it?

Yes, it’s a nail. What’s a nail have to do with a 6m antenna you ask. A quick scan of the instructions revealed that they include it to dimple the radiator tubes onto the tip assembly for fixed operation. Nice touch.

OA-50 assembled

OA-50 assembled

A few minutes later and I have a new OA-50 waiting to be tested. Too bad it’s dark, cold, and raining right now. Dark and cold would be okay, almost normal antenna deployment weather. Rain, not so much.

Now that I have one Omni, wouldn’t two be better? They do make stacking kits. Stay tuned for more!

 

KA9EAK Portable – 6m

The weather was beautiful today and I really didn’t want to do anything that I needed to do so it sounded like a perfect day for Amateur Radio. I checked various propagation sites and saw that 6m was open. This combined with the fact that I had a new (to me) Par Electronics SM-50 6m Stressed Moxon waiting to be deployed made for a good day for portable operation.

I’ve wanted to get one of the Par Moxons for awhile and found one at the ORC spring hamfest. It was complete in the original box and the price was right so it followed me home. The antenna gets really good reviews on eHam and is perfect for portable operation. It is very easy to assemble and is very well made. The reflector is a piece of Flex Weave wire with ring lugs on the ends that screw into the arms that lead out from the driven element causing them to bow in a wee bit. I placed it on the top of a bit over 20 feet of pipe welded together for just this purpose and fed it with about 30 feet of RG-8U.

6m stressed Moxon

6m stressed Moxon

Antenna at a bit over 20 feet

Antenna at about 20 feet

By the time that I got the antenna up and the rest of the station (Kenwood TS-480SAT) assembled the band was starting to get busy. I went to the SSB calling frequency, 50.125 and listened for a bit, hearing nothing I called CQ and got an almost immediate response from WA1T in New Hampshire. Great signal reports both ways and I was working off the side of the antenna at that point. Using my armstrong rotator I moved the antenna around and moved up and down a bit on the band from 50.125 to 50.150 looking for stations. In less than two hours of operation I had made a dozen contacts, most with good signal reports though with some effort as the band moved around. Some stations were there and strong and the next instant they were gone so some contacts were missed. Most all of the stations I contacted were running as much or more power and had larger antennas than I so it was good that they had better ears than mine, but the little Moxon on some pipe in the backyard performed well. More investigation is required in order to determine if the pile of flowers at the base of the mast had any influence on signal strength. Could this be the origin of the phrase “flower power?”

Portable station

Portable station

I heard\called a few Texas stations but the only one that heard me was K5HGX. I also heard\called some stations in zero-land but was unable to complete any contacts.

Map of contacts

Map of contacts

It was a fun afternoon trying out the new Moxon and operating a portable 6m station. Now that I have this nice antenna I’ll be watching for 6m band openings.

Your host enjoying the best hobby of all

Your host enjoying the best hobby of all

 

6m Squalo from a lawn chair

What does an old lawn chair have to do with Amateur Radio?

Hidden in this lawn chair is a 6m antenna

Hidden in this lawn chair is a 6m antenna

Now that I have a 6m rig I need to build an antenna to operate on this band.  I was wavering between a Moxon and a Squalo and after a discussion on the ORC club net last week which included Tom, W9IPR donating an old lawn chair I decided that I’d build a Squalo.

There was an article in the January 2002 issue of QST, ”
Six Meters from your Easy Chair” in which W9SR described the construction of a 6 meter antenna using the aluminum tubing of a lawn chair.  It turns out that the size and shape of the frame of the chair is perfect for building an omni-directional square-loop or “Squalo” antenna.

After drilling out all of the rivets and disassembling the chair it’s starting to look like an antenna:

Lawn chair legs after disassembling the chair.

Lawn chair legs after disassembling the chair

After cutting the tubes to length, cutting and shaping the capacitor plates, and fitting the insulator (3/4″ PVC works fine):

Cut to size with capacitor plates cut and sized.

Tubes cut to size with capacitor plates cut and sized (cat for scale)

Mounting plate and capacitors attached

Mounting bracket and capacitor plates attached

I used a piece of aluminum angle stock (1/8″ x 2″) for the mounting bracket and made a mounting plate for the SO-239 out of a piece of 0.060 aluminum bent so as to position the Gamma match 1″ from the element.

Mounting plate

Mounting plate

Capacitors

Capacitor

Complete antenna with Gamma match

Complete antenna with Gamma match

Since it was late at night and raining outside when I finished construction I suspended the antenna from the ceiling of my radio shack and hooked up the antenna analyzer and it actually works!  Resonant at the bottom of the band!

It's resonant!

It’s resonant in the band!

After the construction was complete and a quick check with the antenna analyzer it was time to mount it outside.  It was an unseasonably warm winter day (44 deg F) so my younger son Ben and I worked on the installation.  The first mounting was on the mast that supports my 10m vertical.  This placed the antenna at about 9 feet.  Not at all optimal but it’s what I had for the time being with the intent to improve the mount in the spring.

Ben and I

Ben and I

Testing at the initial position with Tom, W9IPR and Jim, K9QLP resulted in marginal performance.  Both sideband and FM were sub-optimal.   After checking over the installation and further testing with the antenna analyzer, including using a different transmission line I decided that height was the major factor in the poor performance.  This probably isn’t a big surprise as height, height, and more height are the primary requirements for the best operation at VHF frequencies.

So I decided that some improvement in height couldn’t wait until spring.  Even though the weather was getting cooler (28 deg F) we needed to get the antenna higher in order to improve its performance.  My older son, Dominic (W9KKX) welded two chain link fence top rails together with reinforcement at the joint and the base with conduit.  This gave us a mast of 21 feet.

Squalo at 21 feet

Squalo at 21 feet

Dominic, Ben, and I

Dominic, Ben, and I

The new location provided greatly enhanced performance.  FM simplex is improved and I now can clearly get into the WERA 6m repeater (53.030\52.030 MHz) located in Milwaukee.  Sideband performance is improved but still needs some more work.

The SWR across the 6m band is:

Squalo SWR

Squalo SWR

It’s very easy to move the desired center frequency by adjusting the capacitor plate.  Closer together moves the frequency down and further apart moves the frequency up.  This adjustment isn’t too touchy.  The gamma match is touchy.  I was able to get the SWR down to around 1.2 to 1.3 at 52.715 MHz.  This is good enough for now.  Over the entire 4 MHz of the band the SWR is never above 3.5 so the LDG YT-100 that I use with my the FT-857D is able to quickly find a match across the entire band.

I’d like to thank Tom, W9IPR for the lawn chair that started this project and both he and Jim, K9QLP for taking the time in the fine tradition of Amateur Radio to run some on-air tests with me as I worked out the installation.

In addition to the  January 2002 issue of QST, ”
Six Meters from your Easy Chair” in which W9SR described the construction of the antenna I found an article from the July 1958 QST, “Beam Talk for the Layman” useful for some additional information on the gamma match.

This was a fun and interesting project that resulted in my first 6m antenna.  It’s not a super performer but it got me on the band and with a bit more work it will serve me well.

UPDATE: Here’s a slightly different, perhaps more entertaining version of the story that I wrote for my radio clubs newsletter.