KU4AB 6m / 2m / 432 mHz square loops.

KD5ITM

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Joined
Jan 15, 2024
Messages
13
Location
Spring, Tx.
Who else uses the KU4AB VHF / UHF loops? SQ-50 6m square loop. SQ-144 2m square loop. SQ-432 432 mHz square loop.

In 2010 I bought the KU4AB SQ-50 single loop, SQ-144 stacked loops and SQ-432 stacked loops that I used for VHF / UHF rover operations. I liked how each of the loops worked well that in early 2011 I bought a second set of the KU4AB SQ-50 single loop, SQ-144 stacked loops and SQ-432 stacked loops for VHF / UHF operations at the home QTH. The rover loops are mounted to a 10’ section of 1.25” OD 16 gauge galvanized TV antenna mast. The QTH loops are mounted so that the SQ-50 single loop is up at 35’, the SQ-144 stacked top loop is at 34’ and the SQ-432 stacked top loop is at 33’. It’s been several years since I‘v operated as a rover, so I’m thinking later this fall when this Houston heat and humidity comes back down to reality, of taking the SQ-50 single rover loop and stacking it with the SQ-50 single QTH loop. Since the SQ-50 6m loops when stacking them require a spacing of 12’, I’m going to add another 10’ section of 1.25” OD 16 gauge galvanized TV antenna mast so that the top SQ-50 loop along with the rest of the loops will be 10’ higher which will put the bottom SQ-50 stacked loop up at 32’ high and well above the peak of the roof. This should make for a nice noticeable difference with receive signals and for sure give a nice boost to my 100w signal on 6m sideband. Not to mention a bit of all around improvement with the SQ-144 stack and SQ-432 stack loops with the addition of an extra 10’ gain in height.

KD5ITM - EM20hb - Spring, Tx
 

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vagrant

ker-muhj-uhn
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California
I had never heard of the KU4AB loops. M2 is my neighbor, so I have used their 6, 2, and 70cm loops. The single loop works for me as I am typically around 6000’ (1800m) ASL in the Sierra’s. As they are quite narrow I enjoy them at the bottom of the band for SSB and FT8. The setup is quick and easy. I operate SOP for the contest, so low power for me.

I can definitely appreciate your use of them as a rover, versus fooling around with a rotor. I can imagine the looks you get driving with that. Still, that’s rather tame to some other rovers. From time to time I use Yagi‘s and log periodic antennas, but I’m not moving. I have a five element 6m antenna I sometimes use and that really opens the eyes of people as it is on a mast in a vehicle hitch mount. There are other antennas further up the mast as well.

I might catch you on 6m this September. Have fun!
 

KD5ITM

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Joined
Jan 15, 2024
Messages
13
Location
Spring, Tx.
Where is your QTH? I grew up in the 80s in Westwood Ca up in the Sierra Navadas about 80 miles west north west of Reno.

I first got started with VHF / UHF rover operations in 2007. I first learned of the KU4AB loops in the spring of 2008. What attracted me to Phil KU4AB’s loops was the good reviews and the affordable price. I paid $75 for the SQ-144 2m stacked loops which included mounting hardware and phasing coax. The SQ-144 stacked loops at $75 was the most expansive loops that I bought from him. The SQ-50 6m single loop and SQ-432 432 MHz stacked loops were both under $75. I want to say that if you bought the SQ-50 stacked loops, it was around $115. Back when I was buying all of my different loops from Phil, they seemed to be some what popular. I saw several pictures of different rover setups in QST that were using KU4AB loops. Between 2008 - 2010 when I was buying my loops from Phil, I had zero issues with his customer service. He shipped the antennas quickly and was friendly to talk to over the phone. I guess a few years later after I had bought all of my loops, Phil’s customer service started to go down. I started seeing a lot of people saying that they bought a loop from him and it took a month for him to ship it or that they never received it in the mail and that he was either slow to respond back to you by e mail or didn’t respond back at all. When I was dealing with Phil, I had very good service from him. And in my opinion all of his loops are of a quality build and perform very very well. From what I know, his web site has been down since 2017. I have 2 of the SQ-50 6m loops that Im thinking of stacking. I emailed him back in March and then again a couple of weeks ago asking for the specs for the stacking distance between both loops and the length of the phasing coax. I have not heard back from Phil. According to QRZ, his licenses is still active.

The M2 loops are probably the most popular on the market. If I ever need to replace one of my KU4AB loops, I would have no problem replacing it with an M2 loop.

When I use to operate rover a lot more then I do now, when at a gas station someone gives me a weird look, I just tell them that Im with “Civ-Rad-Com” Civilian Radio Communications lol. The SQ-50 will handle 100 mph wind speeds and 1000w. With just an IC-706MKIIG 100w and a single SQ-50 up at 35 ft, Iv confirmed as of last week, 219 grid squares on 6m ssb!
 

KD5ITM

Member
Joined
Jan 15, 2024
Messages
13
Location
Spring, Tx.
I forgot to mention that when I received my first set of KU4AB SQ-144 stacked loops and SQ-432 stacked loops, a week before the 2010 June VHF / UHF contest. The day I received both sets of stacked loops, I mounted them to the ”rover” 10’ TV antenna mast, that evening from 6:30 pm when I turned on the radio, there was a huge 6m opening that was still going strong when I finely turned off the radio at 2:30 am. I ended up setting the 10’ rover mast in the corner of the bedroom next to my radio room. The top loop, SQ-50, was about 2 inches below my 8 1/2’ ceiling. With just 100w, I was able to work and confirm St. Lucia, FK93, 2,575 miles from my home QTH in Spring Tx - EM20hb. My furthest grid square worked. I can’t imagine how much further I could have talked if I had the loop up at 35’! When the band is open, the band is open. So I have no doubt that the good conditions had a lot to do with it, but thats only 50% of the equation. With the loop only 8’ high, a good performing antenna is the other 50% of that equation!

During the June 2007 VHF / UHF contest, before I found the KU4AB loops, I was using an MFJ-1762 6m 3 element yagi. This was my first time operating 6m SSB during a June VHF / UHF away from my home QTH. More of a portable set up then a rover set up. I parked my truck about 100 yards off of a quiet country back road about 15 miles north of Huntsville Tx, about 60 miles north of my home QTH. Where my QTH is in Spring Tx, just north of Houston, it‘s pretty flat. No hills other then the free way over passes lol. You start to get in to some smaller rolling hills when you get north around the Huntsville Tx area. My home elevation is right at 122’ above sea level. Where I parked the truck and had the 3 element yagi set up was on the top of a hill. Where I had the antenna mounted the elevation was at 480’ with the 3 element yagi up at 25‘ above the ground. I bought the MFJ 6m yagi a few weeks before the VHF / UHF contest and was my first time using a directional antenna on 6m. I had the yagi set up so that I could rotate the mast by hand. At the end of the contest I came to the conclusion that I didn’t like using a directional antenna on 6m. The way that the 6m band opens with the sporadic e propagation, you can have a small opening down to Florida. So you point your antenna to FL, not knowing that there is a much better opening to the mid west. Or the band can be dead for a hour and if your antenna is not pointed in the right direction, you miss the quick 10 minute opening. So I quickly figured out that I don’t like a directional antenna for 6m. Thats what got me to start looking on line at other 6m antenna options and is when I came across the KU4AB 6m / 2m / 432 MHz loops. KU4AB also made loops for 10m and 222 MHz. I also remember Phil offering an antenna that used a loop and a 1/4 wave vertical, I want to say that it was only for 2m. I don’t remember if it received with the vertical and transmitted with the loop. I kind of want to say that the loop was used for 2m side band and the vertical was used for the FM repeaters. Not sure how it all worked and I don’t think it was a big seller for him compared to his loop and stacked loop antennas.

So, long story short, I much more prefer an omnidirectional antenna for 6m SSB then I do a beam / yagi. I lose a little bit of performance with the lack of gain, but at least with the loops, I can receive / transmit in all directions, don’t need a rotator and the loops make for a quick and easy portable / rover set up.


 

vagrant

ker-muhj-uhn
Premium Subscriber
Joined
Nov 19, 2005
Messages
3,610
Location
California
I am near the Fresno area. As to omni versus directional, during my time participating in the ARRL VHF Contest, I found that many/most of my contacts were north of me. I even dedicated more antenna time with the yagi to the south and I was still catching more off the back of it. Additionally, I found stations participating in the contest started to fall off sharply south of Fresno. Thus, the move to using directional antennas more often and enjoying the benefit of it. I can easily work Modesto to Bakersfield between the coastal range and the Sierra's. There's a few areas where I am shadowed, but I am not really looking for points and rather enjoy the experimenting with different antennas from handheld, to mobile, omni and directional. Another reason for the Yagi is when Canada, Mexico and the eastern U.S. pop up on the magic band. It definitely helps.

For a quicker setup on the five element I purchased for $50, I pulled up the PDF for it's three element brother and marked up everything using different colored markers, so I could easily go with five and enjoy the gain, or with three and get a slightly wider spread. I also use wing nuts where I can along with hose clamps that use thumb screws. I transport it in a nylon bag originally made to carry flags. ( I recently picked up a new in box Cushcraft TEN-3 for $30 at a local swap and I'm marking it for the lower end of 10m along with giving it the wing nut and thumbscrew clamp treatment for quick setup/takedown while camping )

Another 6m favorite with a quick setup is the Diamond A502HB. It handles the 6m band, so I can dial up/down, versus the narrow loop. I marked up the elements on that as well to improve setup, which is now ridiculously quick, for a yagi. I believe it is based on the HB9CV two element design. It is incredibly light and easy to armstrong.

Getting back to omni directional, I also use the Lakeview 6m Hamstick from time-to-time. I ran some wires from the antenna base to my vehicle roof rack screws to help with the ground plane. I enjoyed the recent results with that antenna on FT8 during the June contest as SOP.
 
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