Category: Amateur Radio

Summer antenna maintenance

Dave Mueller

Every summer I try to spend some time upgrading my station and antennas. This year was a bit more difficult, due to my medical condition. Besides, I had a difficult time coming up with things to improve. I’d pretty much maximized what can be done from this QTH, given the restrictions of bring in military housing.

Since it’s been three years, I spent most of the time renewing all the guy ropes and other lines that keep the antennas in the air. I use 550 para cord everywhere. It is strong, cheap, and seems to resist UV quite well from my experience. All lines got renewed – for the Spiderbeam and 80/160m vertical. Additionally, I renewed the ratchet straps on the roof that helps to lock the Spiderbeam mast in place. The three-year-old nylon straps were faded, and the ratchets themselves had turned into large hunks of rust.

One upgrade I did accomplish was to build a new 6m yagi, based on G0KSC’s excellent loop fed yagi designs. I chose his 6.8m, 6el design and tweaked the dimensions with EZNEC. Justin’s design uses single piece elements, which requires tubing lengths too long to easily ship to Guam. I essentially modified the design to use tapered elements, and purchased the aluminum from DX Engineering.

For insulators, I used fiberglass blocks cut from 1/4″ GPO3 sheets available at McMaster-Carr. The material is inexpensive and is easy to work with (cut and drill).

The new 6m yagi brought some excitement over the summer. I worked two stations in the Ukraine, a station in Israel, W7GJ on EME (Earth Moon Earth), and even copied CT1HZE in Portugal – a very long haul on 6m.

KH2/N2NL antenna farm, summer 2013
Another view of the antenna farm
New 6m yagi, based on G0KSC’s loop fed yagi designs
New 40/30m vertical (utilizing the existing radials)
Closer look at the feed point of the 40/30m vertical
New 6m yagi, built using the skeleton of a Cushcraft 50-5 and some new aluminum tubing from DX Engineering
close-up of the feed point
One of the element insulators, utilizing the old cushcraft element-to-boom clamp and a piece of 1/4″ fiberglass
View of the loop feed and matching balun which runs parallel with the boom

 

Receive antenna maintenance

Dave Mueller

The week before the ARRL DX CW contest, I figured it was time to walk the receive antennas again. It’s been a few months since I’ve done it last, and due to some windy conditions, I expected to find some issues.

Tree branch fallen against the Beverage wire – the vine behind the branch is a troublesome species since it grows so quickly.

As expected, I found a number of issues, mostly branches and vines that had fallen across the Beverage wires. Fortunately none were broken. I allow the wire to “float” through the insulators, so a branch will usually pull the wire to the ground but not break it.

The vine in the above photo is especially troublesome. They grow extremely fast and are very strong and difficult to cut with a machete. They often trip me up when walking in the jungle. Because of their strength, apparently they are used in the Philippines to tie up farm animals. In several places these vines quickly overwhelm the receive wire.

Signature of a hunter

The area where my antennas are located have been unoccupied since WW2. Unfortunately, however, poachers have started hunting on the land, which is Government of Guam property. They leave telltale signs – such as the water bottle above. It is really sad that they do not pack out their trash, however I see it everywhere on Guam even in the most remote areas. Water bottles, beer cans, and Mr. Brown’s iced coffee cans scattered where hunters sit and wait for their prey. Fortunately, none of my antennas have been disturbed, however metal theft is a huge problem on Guam so it may be a matter of time until my antennas start disappearing.

Coconut fronds are heavy and easily pull the wire to the ground.
This honey bee hive is located right next to my longer North American beverage. Fortunately they are not aggressive. Apparently these bees are somewhat rare on Guam.
A pig rubbed up against this tree, damaging the feed point connector. It still works however I’ll have to replace it at some point this spring.
A pig rubbed up against this tree, damaging the feed point connector. It still works however I’ll have to replace it at some point this spring.
The red arrows point to tooth marks in my African Beverage termination where a pig grabbed the wire in its mouth. No real damage fortunately; usually they don’t see the black wire. White wire gets torn to shreds quickly and I can’t use it in the jungle.
This fully loaded M1 Carbine magazine sits where I found it last year, under my original North American receive antenna. It has sat here since 1944, where it was left at the edge of a Marine’s foxhole probably on August 6th, 1944, when this was the front line during the Liberation of Guam. Pretty cool stuff – which fascinates me.

 

Stew Perry contest

Dave Mueller

I listened around and called stations during the Stew Perry 160m contest this weekend. I made two sweeps of the band, one at 10Z and the other at 11Z, recording what I heard.

1000z recording: JH2FXK, N9RV, K9YC, K8IA, W7EW, DU7TET, K7NJ, N0TT, W7RN, KG6H, KH7X

1000UTC recording:

1100z recording: JA3YBK, AA5B, N5RZ, N6RO, N6KI, K9YC, ZL3IX, KH6LC, K8IA, JE1ZWT, W7EW, N9RV, K4PI, K1DQV, N8UM, WD5R, K3ZM, W5ZN, W2GD, NH7O.

1100UTC recording:

If you hear signals changing abruptly in strength – it is because I am switching between Beverages. The band peaked into NA here at 11z – Eastern stations actually got weaker as SR approached. Also, there were times when signals were skewed south of direct path; the 045 degree Beverage was best when normally the 030 wire hears better.

Beverage Antenna Repairs

Dave Mueller

We have had some gusty winds this winter (perhaps up to 35MPH), and I noticed that my African Beverage had gone deaf. Since this is long path season into NA, and since this is also the heading for NA long path, I figured I needed to repair it.

It turns out that a large branch had fallen on the wire very close to the feed point, snapping the wire at the feedpoint insulator. I float the wire through insulators along the length, so a branch falling usually does not break the wire, but in this case since it fell close to one end, it broke. Anyway, it was an easy fix, and all six Beverages are once again operational.

It isn’t pretty, but it works. I don’t waterproof boxes because (1) it isn’t necessary and (2) it is easier to trap water in such a “waterproof” box than keep it out. Better to let it breathe.
Typical terrain and growth in the jungle
Pretty much looks the same in late December as late July; the temperature remains the same year around. There usually is less humidity in the winter so it feels much cooler.

SU9VB on 160

Dave Mueller

Here is SU9VB on 160m, as copied here on Guam with a 900ft Beverage. Vlad started calling CQ at 2000Z and was very weak – 449 peaks every couple minutes, ESP copy the rest of the time.

At 2035Z he started to peak, and was so much louder than before that I was worried he was a pirate.

Unfortunately there was QRM from UY5AR and others in Europe. When I was sending my report, it was right at my sunrise (2041z).

Zone 34 is the last zone for 160m Worked all Zones from Guam.

 

Great low band conditions

Dave Mueller

Now that the fall contest season is over, I can enjoy DXing on the low bands throuigh the holiday season. The low SFI number may worry some, but for me, it means great conditions on 80 and 160m. I recently have broken 2,000 unique calls worked on both 80 and 160m, and would love to push that number up quite a bit higher this winter season.

The past few days have been excellent into Europe on 160m and North America on 80m. For some reason, I am not seeing reciprocally good conditions into NA on Top Band. Not sure what aspect is keeping this from happening. I am imagining some high MUF bubble in the mid Pacific that is causing absorption, not unlike a Bermuda High Pressure system, but this is just a guess on my part. Either way, the good conditions I am getting on 160 into Europe are just not happening in the other direction.

Here is a 11mb MP3 I made on December 8th, while running Europe on 160m. Signals are excellent. On this day, propagation was best into Southeast Europe.

This morning I worked about 40 more EU on 160, with conditions extending all the way into the UK, with GI3OQR the best DX worked (a new one for me!)

PT0S signal on the low bands

Dave Mueller

On the last day of the DXpedition, I was able to get my computer set up to make a couple quick recordings of PT0S on the low bands. Both are long path (near my sunset), nearly a 12,000 mile path from Guam. Long path bearing is 157 degrees and I was listening on my new 160 degree Beverage.

On 80m, I do some VFO A/B switching so you can hear the pileup on the split frequency. The JA’s are several S-units down from normal since I am hearing them off the back of the Beverage.

On 40m, there was a lot of QRMing and “frequency cops” going on. Everyone says how well behaved the Japanese operators are in pileups. This proves that wrong. Still, almost all Japanese hams show very good courtesy on the radio, but the numbers of lids in Japan is increasing. During PT0S where was a lot of intentional QRM, even out of JA. I suspect this was due to the rarity of this entity in this region. As a side note, I think someone else was using JF3SUL’s call.

Even though the path is longer, signals were better via long path than short path every time. Short path is over Japan and Europe, and is about 9,800 miles in length. In comparison, the 80m signal was at times 579 on LP but at most 559 SP.

I did copy PT0S well on 160m on two occasions, via short path. Signal was Q5 copy both times but very weak – not workable strength with my antenna. I regret that I did not have everything connected to make a recording, and they did not appear on TB the last day until just after my sunrise. I wonder if a long path 160m QSO would have been possible, but there was no mutual darkness on this path. My sunset missed their sunrise by about 10 minutes. This probably was just enough to kill any chance because my experience from here is that 160 propagation dies within a couple minutes following sunrise. That said, I have a very solid path into PY2 on 160 and LP signals were much better here than SP, even though I have better “ears” (longer Beverage) into Europe.

Mission Complete

Dave Mueller

Earlier this year I decided to try to operate all three CQWW DX contests seriously, to see how I could do.

First, in September was CQWW DX RTTY. It looks like I finished in the top 10 in the world, and broke the existing Oceania record in the process.

Next, in October, came CQWW DX SSB. This was the contest that worried me the most. In 1999 I had operated as KH2/N2NL from KH2JU’s QTH, crashing hard at about the 40 hour mark and finishing with just over 5,000 QSOs and about 7 meg. The station I have put together works well, but I did not anticipate making much more than 5,000 QSOs. It turns out that I did much better than I expected, finishing with over 6,000 QSOs and possibly an eighth or ninth place finish in the world. I fell just over a million points short of Jose CT1BOH’s Oceania record (as KH7R) but it appears that I won the continent, beating a very spirited effort from geographically disadvantaged Hawaii by NH6V at KH6LC.

Finally, last weekend was the CQWW DX CW contest. I had broken the record last year and have all the confidence in the world in this mode (my favorite by far is CW), but I was not looking forward to another 48-hour effort. Once the contest started, however, there was no turning back and when rates were similar to last year, I pushed hard to try to beat my QSO count from last year. I was successful in doing this, making just under 6,500 QSOs and breaking the Oceania record I set last year by over 1/2 million points. It also looks like I may have made the top 10 again, something I am extremely proud of doing from this part of the world.

Contest season for me is over, however I probably will make a few QSOs in the ARRL 160 and 10m contests. CQWW 160 in January is also a fun contest. In the mean time, I will probably continue chasing DX and working the low bands.

Beverage antenna splitter

Dave Mueller

This week I wound a simple Beverage RX antenna splitter – 12 turn primary on a 73-202 binocular core, with a 16 turn secondary center tapped and grounded through a 33 ohm resistor. The idea is to share my Beverage switch box between both radios. This should help me with multipliers on the low bands, an improvement over the past where the 2nd radio could only listen on the noisy low band transmit antennas.

Thanks to N0AX for deciphering my spectrum analyzer for me, but it looks like about 4dB of loss through the transformer, with good isolation between both outputs. Theoretically I could get 3DB loss with a Magic T splitter, but this is fine for Beverage antennas. It seems to work well, and it appears I may even be able to do some same-band SO2R with some of the more remotely located Beverages I have.

The signal was zeroed out to the 50dB line before putting the splitter in-line – shows about 4dB loss on 3.5 Mhz (similar measurements were found on 1.8, 7.0, and 14.0 mhz)

 

Another new Beverage Antenna

Dave Mueller

Yesterday I finally got the chance to install a 6th Beverage receive antenna. The new one is pointed at 160 degrees – about the line separating zones 30 and 32. The new antenna should help not only with VK/ZL, but also Europe long path on 40 and perhaps even 80m. This had to be a short one, about 450ft long, because the housing area and fence meant that I would have to place the feed point deep into the jungle – the deeper I go, the more coax loss countering the performance gain of a longer antenna. I ended up using about 500ft of RG6 to reach the feed point from the remote coax switch that is already 400ft from the shack.

Last night the antenna seemed deaf. While laying in bed – the light bulb went on in my head – I was a doofus and had forgotten to splice the two pieces of wire I used to make up the antenna. Essentially I had been listening on an unterminated, 75ft long Beverage. After I fixed it this morning, the new antenna seems to be hearing normally now.

Here’s the splice point I had forgotten yesterday. A terminated 450ft long antenna hears better than an unterminated 75ft long one!
Yes – the beverage transformer is housed in a Tic Tac box. It’s all I had at the moment, and I only care to keep the transformer somewhat dry and protected from the rain.
Yes – the beverage transformer is housed in a Tic Tac box. It’s all I had at the moment, and I only care to keep the transformer somewhat dry and protected from the rain.
The new wire passes through an area used as a late WW2/immediate post-war dump. These are beer and liquor bottles dated 1945-1947. The Beverage passes through a field of Beverage containers – good luck?

Today, when I finished the splice, I had to clear off a tree that had fallen on my old North American Beverage. The insulators I use allow the wire to slide through them – so tree falls like this normally do not break the wire and allow the antenna to still function.

Nice day in the jungle – sunny and not too damp today
This tree fell when it became overgrown with vines.

While walking the 045 Beverage, I crossed some cigarette butts under the antenna. I had heard a couple gun shots last weekend – pig hunters – but didn’t realize that had been in the vicinity of my wires. Either they did not see them (the #18 cu clad wire is almost invisible) or they are respecting them. Copper theft is very prevalent on Guam but most hunters I’ve seen in the area are responsible people and I let them know what the antennas are for (and that the cu clad wire is almost worthless as scrap). The fact that there are hunters in the area are why I do antenna work mid day, when the hunters are not active (pigs are active in morning and evening) and why I wear colorful clothing and make a lot of noise. I don’t want to be mistaken for a pig or deer!