With that out of the way, I was on a search for some aluminum and recently encountered a Hy-Gain Explorer 14 (EXP-14) that was in the attic of a local ham. I knew nothing of this Hy-Gain model, but the specs seemed to be right in line of what I was looking to accomplish. The price was right and it was in excellent condition. In speaking with the seller, the beam used to belong to a local club who unfortunately lost access to put up towers for field day and this beam was one of the casualties.

The Hy-Gain EXP-14 has a unique feed point (as they even state in the manual) with parasitic driven elements on 10m. It weighs approximately 45lbs, 14ft boom with a 17ft turning radius, perfect for my rooftop mount.

I had to beam built, tuned and installed in what seemed to be record time, only taking 3 1/2 hours. Part of that time included running out to Home Depot for a 12″ mast (above the rotor) and prepping the coax with ring terminals.

Once the beam was up, I could hear a drastic difference compared to my temporary bob-tail curtain on 20m. The first stations I heard were from India and Oman. Keep in mind, all of this was going on during the CQ Worldwide CW contest that I unfortunately could not commit a serious amount of time in due to the holiday, but ended up being a good time to test the new antenna and tweak the station.

The antenna is only sitting about 25ft off the ground, 6ft from rooftop. I was concerned with takeoff angle with the antenna being so close to the ground, but the fact that I was able to work into the Middle East, India and Asiatic Russia all while barefoot, says something.

In the photo, it may look like the antenna is mounted to the chimney, which it is not. The mount is a modified non-penetrating roof mount for DirecTV-type satellite dishes with 8 low-profile concrete blocks acting as ballast. The lower mast is guyed to the plate that holds the blocks. The mast is then guyed to the 4 corners of the house and attached just below the rotor.

During the 4 hour trip, I worked a number of DX stations on 17 and 20m including Russia and Belgium. Having HF in the car definitely makes the time go quick, but logging becomes the difficult and hazardous part.

Once on-site, our tour guide took us around league headquarters where we visited the Logbook of the world (LoTW) and certificate department as well as Product Test Lab, Marketing & Advertising, and VEC departments. While there Laurie (KB3SIK) was able to find out the status to her recent upgrade, which happened to arrive in the mail that day. In the outgoing QSL card bureau, we found cards destined for NE3F, the local contest station in Reading, PA, which I found rather funny.

We also had a tour of the ARRL employee station, W1HQ which had a decent amount of gear including a SteppIR beam and 6 meter King Conversion amplifier. I’ll be adding W1HQ to my rare DX list.

It was nice to be put faces and names to the ARRL and see what they do from their perspective. They do alot with what they have and make use of every piece of equipment they have; Something quite apparent in the Lab and Art departments.
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After lunch at a local pizza place, we put in some operating time at W1AW, their visitor operator station. W1AW is also the station that provides the on-air ARRL bulletins as well as qualifying Morse code runs. I ended up running their Yaesu FTDX-9000D on 15m for a bit. The station has alot of different gear and operates a number of modes.
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The remainder of the photos and video can be found here.

The following day, Laurie and I made some adjustments to our 2 meter stack by adding a tilt-over base which allowed me to change the polarity on the cubical quad. Now I can get into N2KEJ’s repeater in South Jersey.[simage=463,576,n,center,][simage=462,576,n,center,]

Well it arrived today and I think I’m going to stick with my new D72A. The F6A is a little too small for me, although the fact that it can receive AM/FM/SSB and CW is a real help. Hopefully she’ll let me borrow it for our future outings. Check it out!
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How to resolve this? Reduce your coax run length and quantity by using antenna switches.

I reviewed a number of designs online and ended up designing my own, 2 position antenna switch which injects 12VDC onto the coax, so we didn’t require additional long lengths of control wire which could end up resonating RF.
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For the next 3 weeks part of my station would be turned into an assembly line, etching circuit boards, fabricating cases, etc.

A week before the contest, Eric and I put the switches through their paces by dumping 2.5kW at 100% duty cycle for about 10-20 seconds. This would help us assure that they would hold up to the contest pace.

I ended up building five switches, 2 rated at 10kW and 3 rated at 5kW. I’m happy to report success with the design with no smoke emissions. One thing we did find was a high SWR at 15m and above, which I believe I have a fix, that needs future testing.

Barry, KU3X and I discussed the capabilities of 160m mobile in the summer. He had a successful coil design for his mast and whip combination with good signal reports into our nightly 160m net on 1900khz.

Fast forward to this last weekend where I acquired a quick disconnect (QDC) for my screwdriver antenna and a spool of 16ga enameled wire from the LVARC table, all at the Cherryville Hamfest in NJ. Now that I had the wire and QDC, what better time to build the coil and attempt to go mobile on 160m with my High Sierra HS-1500MKII screwdriver antenna.

At first I just winged it, and used a 3 inch PVC as the coil form, with 7 inches of exposed PVC between the end caps. I ended up with a 100 turn inductor that I would later discover calculates to 390uH of inductance. After reviewing someone elses blog about an inductor for this purpose, I ended up being about 110uH of too much inductance. After a little experimenting, I removed about 20 turns and tested again. I had found my resonance was around 5850khz.

This is where I started utilizing my MFJ-259B analyzer beyond the typical SWR readings. I had found a relationship to inductance at the resonant frequency to be 0uH, and 25uH at 1900khz, our target frequency.

With this new information I removed another 5 turns and now found I was around 4:1 SWR at 1900khz with resonance still up and around 5Mhz. It was then I remembered that the 40m shunt coil at the base of my antenna was still in the circuit. Once I removed the matching coil, SWR came down to 2:1. All I had to do now was to raise or lower to the desired resonance, 1:1 at 1900khz.

After I had the test case completed successfully, I re-evaluated the connection points, I decided to drill an entry point to wire the coil from inside the coil, which makes for a cleaner appearance. I also decided to anchor the caps with 4 screws each and not sealing the form in the event of internal coil failure. Because of this, a drain hole exists at the base, only millimeters away from the bottom connection point.
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Here are the specs on the coil:
Length not including quick disconnects: 11 inches
Turns: 75 (i think)
Calculated Inductance: estimated 270 uH
Tuning: Allows tuning down to 1815khz at 1:1 with screwdriver fully extended.

On air reports were surprisingly good. I have an Icom 706Mk2 running 100w.
I was S9+20 into Pittsville, MD, S7 into Western PA all from the Pottstown, PA area. This is typical of what I expected, but never that great of a signal.

I’m planning on building another coil with a few less turns with hopes of bringing resonance down to 1800khz even. Then this will truly be a 160m coil.

–jeff
N3QO

Any New Year’s resolutions? At first I didn’t think I had but I guess mine would be the following:

-Actually learn code (CW) besides, CQ DE N3QO, 5NN and TU. A future post…
-Not spend as much money on the hobby as I have in last 2 years, although a Flex 3000 is in works.
-Timonium Hamfest, Timonium, MD.
-Dayton Hamvention. Enough said.
-Sussex Hamfest, I missed this one in 2010 because of work on-call.
-The 2011 antenna projects. See next post.
-..and finally, operate more, build less.

Writing the last post (year in review), I realized I did more station building than actual operation. I’m hoping we have better sunspot performance this year, but now I’m poised to hunker down and start working some DX.

With the change in antenna size, weight, etc we were able to extend the mast another 4 feet and add a 6′ mast above the rotor. At approximately 40ft is the 2m vertical, with the quad at the bottom set to horizontal polarization. This allows for another antenna to be mounted in the middle, most likely another 2m cubical quad vertically polarized.

The idea was to scrap the satellite station project and move the Hexbeam to the roof a few weeks after the initial move. With some help from Harry (K3HVC), we were able to relocate the Hexbeam and retune it a bit. We also made room below the Hex for the home for a future 6m beam. Wiring is already complete, so installation should be cake when that day arrives.

Signal reports have been phenomenal. A week or 2 after the installation there was a 10m opening which I was easily able to work South Africa, barefoot without issue. 10-15+ signal reports working barefoot were welcomed.

Overall, I’ve been very happy with the decision to go back to the Hex. For my particular installation, it seems to be the best choice.

Hoisting the antenna up on the 25ft mast was quite a challenge, but it’s up. Unfortunately I misjudged the site where the antenna is located but putting it too close to my 40-80-160m inverted Vee and miscalculated the distance from some tree branches.

I would call it a failure, although I found the signal strength comparison between my previous Mosley TA-33 and Hexbeam to be a night and day difference. The Hexbeam works circles around the TA-33 which surprises me. Initially when I went from the hexbeam to the Mosley I didn’t notice too much of a change, but comparing it now having gotten used to the tribander for the last 6 months, I’m very happy with my decision to return to the unconventional design.

Now, I’m not saying the TA-33 is a bad antenna, but for my location it isn’t optimal. The beam was mounted 8ft above the roof around 25ft above ground. I think an antenna of this design would be optimal around 50ft and away from the house. I had found it to become quite a noise antenna that close to the house.

For this close proximity to ground, the hexbeam seems to be the best option I have available to me. A cubical quad may also be a good option as well.

So Sunday the plan is to relocate the antenna 20ft from it’s current site, which should prove to be quite a job. I’m hardly looking forward to installing new ground anchors.