80/160m vertical work

Today I completed some work on my 80/160m vertical. My design is somewhat unique, using two parallel vertical wires connected at the feed point – one side is 1/4L on 80m, the other side is connected to top loading wires and is resonant on 160m. The system works very well for me and allows me to share one extensive radial system.

Until today, I always used copper clad window line for this vertical section, because the rigid spacing would keep SWR from fluctuating. I have had lots of problems with mechanical strength however, both with broken wires and some arcing issues if I was transmitting when the wind blew the line into a wet tree branch. This quick arc would burn off the copper cladding, and the steel core would quickly rust, form a high resistance point, and eventually break.

Yesterday I made up a length of homebrew balanced line, using spacers made of 1/2″ PVC sprinkler line which is very light, cheap, and easy to work with. The new antenna should be much more reliable and easy to repair. I also made some extra effort to keep the wire away from branches.

This is the top of the vertical portion of the antenna – left vertical wire for 80m (terminates at the white PVC insulator), right vertical wire continues up to the three top loading wires for 160m.
The feed point has not changed, but you can see the two vertical wires connected together at the feed. The white vacuum relay and coil are used for matching purposes on 160 and acts as a hairpin match.
Here’s the top of the antenna – you can see the new ladder line and the three top loading wires used for 160 and also to support the somewhat flimsy mast in the wind.

CQWW DX SSB results and preps for the CW weekend

I’ve been bad about updating this site. I suppose it is a good thing, but I have been extremely busy – but I know there are those who visit here periodically so I need to be better about updating.

The CQWW DX SSB contest exceeded all of my expectations. I had hoped to break 5,000 QSOs – which would match my last SOAB effort from Guam in this contest back in 1999. It turns out that I broke 6,000 QSOs – but fell short of the Oceania single op record. Conditions were good, but not good enough.

Here is the breakdown:

Summary:
Band QSOs Zones Countries
——————————
160: 5 3 5
80: 124 27 35
40: 602 29 67
20: 1227 35 103
15: 2014 35 96
10: 2414 36 100
——————————
Total: 6386 165 406 Total Score = 10,602,889

This score is very close to my CW score from last year. I had more multipliers in 2011, but the QSO total is within 100 or so.

I found a number of small issues with the station during the contest. Most of all, my new remote Beverage switch, utilizing the LM3914, worked very poorly. Specifically, it introduced noise into the feed line, which reduced the effectiveness of the receive antennas. Additionally, the noise floor on my NW and W Beverages was much higher than earlier this year – by 5 or 6 S-units. The European Beverages used to be my quietest antenna, but for the contest it was the noisiest.

I replaced my LM3914 “experiment” with a new design, using +12V, -12V, and 12VAC to switch between four antenna positions. Design is similar to the RCS-4. It works fantastic and all the noise generated by the 3914 IC is gone. I also found and corrected the source of the noise on my NW and W Beverages – a bad connection in the RG-6 cable that feeds these antennas. The bad connection allowed the antennas to function, but high resistance allowed ingress of common mode noise from the shield. Once fixed, my European Beverage is now as quiet as it has been in the past.

Last week I had just finished working PT0S on 40m CW (seconds after sending 5NN) when I heard a loud BOOM of thunder and a loud snap in the shack. I had taken a very close lightning strike. I was completely unaware that a storm had moved in, and lightning is rare on Guam. Turns out I was lucky. So far, the only apparent damage is to one antenna port in my 6X2 antenna switch and the house telephone. I am able to bypass this antenna port – and should be ready for next weekend.

I have a few more things to wrap up this week also before the contest. It’s been busy to find time, because of my work responsibilities as Port Engineer. I have a ship that just entered an availability, so my work load will be greatly increased until the project is complete next February. Here are some photos of the haul out of USCGC ASSATEAGUE, a 110ft Island Class patrol boat based here on Guam.

Looking down at the ship from a camera mounted to the main crane hook about 150ft high.
Divers check out the position of the lifting cradle under the ship
ASSATEAGUE is in mid-air as the floating cranes are shifted around to the pier where the ship will sit until work is complete.

CQWW DX SSB preps

I’ve been quite busy the past few weeks trying to finish some station improvements before the CQWW DX SSB weekend. SSB is my least favorite mode, but if conditions are good, you can have sky high rates which makes up somewhat for all the QRM. My station works much better on CW, but the WW SSB is one of the greatest contests of the year.

First of all, I had to repair my 80/160m mast. The bamboo was a good idea, but when I pulled a little too hard to try to clear the vertical wire from a branch, it snapped off about 2ft from the top. Down it came and in it’s place I put up 70ft of aluminum mast – somewhat flimsy but fine for the 20-30mph trade winds we get here. Before I pulled the antenna up, I hoisted up my GoPro camera and got some bird’s eye view photos from the 70ft level.

Looking straight down at the tree
Looking northeast toward North America – you can sort of see my 40m vertical next to the ladder in my back yard. The Spiderbeam is nearly invisible in this shot.
Looking due north. There is a slight down slope in this direction, but the fish eye camera lens makes it appear much more than it actually is. All of my Beverage receive antennas are in the jungle beyond the fence.
Looking east – most of the houses are vacant, with the exception of mine (closest to the left) and my neighbor (NH2KD, on the right).

As you can see, the takeoff is not spectacular but is not bad either. The biggest advantage is that this location is pretty quiet most of the time. There are moments when I have power line noise to my south, but there is nothing but jungle to the north.

Once I got the 80/160m antenna back up, I finished building my new remote coax switch. My soldering turned out to be a total mess, partially because I was pressed for time and because I used mostly parts on hand, but it works very well.

dead bug construction at its ugliest!

Essentially, I took my original Beverage switch box built in 2006, and modified it. This switch box uses momentary push buttons to select and latch an antenna, which makes it easy to switch directions quickly. Inside this box is a LM317 with set resistors for R2 to vary the voltage output depending on which antenna is selected. This voltage is then “injected” into the RG-6 feed line through a RF choke and HV capacitor.

At the far end, the DC voltage is “extracted” from the feed line with another RFC, and there a LM3914 chip senses the voltage, selecting an output depending on the value. This output drives a PNP transistor which activates a relay with a 5V coil, selecting that particular antenna. The chip and the relays are driven by a 7805 regulator at the far end. I only use it to switch between 4 different antenna, but it is capable of selecting up to 10. Thus – I am now able to remotely switch between four different antennas on this particular feed line without any additional wires. I do have a second feed line running to the jungle which I still use my standard two-position switch to feed two additional Beverages.

I now can listen in 5 directions: 240 (Africa/SE Asia), 330 (EU/JA), 030 (NA – longer feed line but quieter RX toward NA on 160), 050 (NA – shorter feed line so it performs better on 40/30m), and 110 (SA). I still am planning on installing a Beverage toward VK/ZL before the CQWW DX CW weekend.

CQWW RTTY

I operated the CQWW DX RTTY contest a couple weekends ago and conditions on 10 and 15 meters were fantastic. Zones 40 and 33 can be extremely difficult from here, due to the polar path, yet I was able to work TF, CT3, and CR2X which is one of the most difficult countries to work from here due to propagation. This is similar to someone in W3 working UA0 in zone 18 on 10, or a European working KH6.

Conditions on the low bands, however, were dismal. I could get nothing going the 1st night and wasted a lot of time CQing on 40 and 80 for few responses. Everyone was on the higher bands! Tropical systems all around Guam added to the noise, and a strong tropical storm over Japan probably curtailed activity somewhat.

The claimed score is about 1 million points over the Oceania SOAB record – so my goal was met – but I felt I left a lot on the table. If I operate this contest again next year (if I get the 1-year extension I requested), I will have to try to do more on the low bands and try some dual-band CQing. I probably could have added 20-30 QSOs or more per hour had I tried this.

This past weekend was the Oceania DX SSB contest. I made only a few contacts; the EU pileup quickly became unmanageable and unruly so I shut off the radio. We had a threatening weather system that put us in a higher typhoon readiness condition. This meant I had to take down my 80/160m vertical and almost my Spiderbeam. As a result, the station was not ready for a full effort.

Receive antenna success

After going through the effort to install a new NA Beverage (see previous posts), I was nervous the first time I listened with it. Turns out, I needed not to worry. The first station I listened to was VE1ZZ – the most difficult area in NA to hear on 160 except for VO1. He was peaking 559. Better yet, I had no copy on him at all on the old NA Beverage, the one I have used for the last 18 months.

I can tell that there is some feed line loss – this antenna seems to have less gain – but there is no hint of line noise, which is constantly present on the old antenna, sometimes S2. The noise floor is significantly lower – by 12-18dB – but signals are about the same strength.

Today I disconnected the old NA Beverage and reconnected the SA wire. I will probably take down the old NA Beverage and use it for a new receive antenna toward New Zealand – a direction which can be somewhat difficult for me to copy currently. A 160 degree heading should cover ZL, east VK, and EU long path quite nicely.

Before then I need to build a new remote coax switch capable of switching more than two antennas. I’m working on a schematic now built around a LM3914 chip and a bunch of 78XX DC regulators. I should be able to design something that can switch 5 antennas remotely with only the feed line – no control wires.

The station is set up now for CQWW DX RTTY this weekend.

I have RTTY working on both radios so I should be SO2R ready (two CPUs, stations interlocked via PTT lines and W6NL designed lockout box using NTE2357 devices). If you’re wondering what the two feed lines are that run under the amps; these have BNC quick-disconnects so I can manually insert bandpass filters. Not much of my station is automated.

 

Walking Beverages

I generally have to walk all my Beverages about once a month. If I don’t the growth becomes overwhelming. It may not be true, but I’ve felt that wet vines, branches, and leaves tend to cause some attenuation if they contact the uninsulated wire in too many places. Walking the antennas regularly allows me to try to keep the jungle at bay, before it becomes a huge clearing project.

Yesterday, while working on clearing the route for my soon-to-be new NA Beverage, I brought my GoPro camera. Once I finished clearing a path to what will be the termination point, I turned it on and walked back along the length of the new trail I had made. This video will give you an idea of what it’s like to walk in the jungle here on Northern Guam. The area is very typical for what you find in the northern forest, however I chose a route that was less heavily overgrown than many other areas in an attempt to make my job clearing easier.

You may notice that I am walking slowly. This is on purpose, to keep from tripping over vines, roots, and rocks laying on the ground. Additionally, you will notice that the jungle is absolutely silent. There are no birds in the jungle, which is very much in contrast to my housing area where birds can be heard chirping all day long. Why? Because of the brown tree snake. You will never find one in the jungle, but they are everywhere, masters of disguise hiding in the tree tops during the day. The birds have migrated out of the forest and into trees on base, because it is protected from snakes by a barrier of snake traps. It can be eerily silent in the jungle, and I’ve often been startled by the quick explosion of noise which occurs when I stumble into an area where pigs have bedded down for the day, as they crash through the jungle running away.

[I need to relocate my video on Youtube.  I didn’t upload it on my normal account.  The link did not survive in the archive copy I am using to rebuild this site in Dec 2020]

By clicking on the Youtube icon at the bottom right of the imbedded video, you can watch a higher resolution version in a new window.

New Beverage project

From Guam, there are two primary directions for radio: NW for Europe and NE for North America. I have two long (~1000ft) single wire Beverage receive antennas, one toward each population area. My European (NW) Beverage hears incredibly well, as there are no noise sources for 1500 miles in that direction, only jungle and ocean. Unfortunately, I suffer some noise in the North American direction on 160m, usually hovering about S2. This noise only affects Top Band for some reason, and the source is line noise from civilization about 1 mile distant in that direction. At times, the noise has made it difficult to copy the next layer down of NA stations calling on 160. I’ve decided to try to mitigate the noise by laying out a new Beverage for NA.

Existing NA Beverage

The existing wire is just over 1000ft long and is pointed at 046 degrees – the center of the continental United States. It has served me well, allowing me to complete 160m WAS, but it is still noisier than I would like. This antenna is already version 2.0 of my NA receive wire, located further west (deeper in the jungle) from the original version 1.0 which was even noisier but closer to the road and power lines.

The new route is significantly further west and deeper in the jungle. The feed point is about 1300 feet from my house, and will be fed by quad-shielded RG-6. Over the past week, I have taken time to mark out the route, clearing a path along the way.

New NA Beverage route

I brought my new Nexus 7 tablet which comes with a GPS receiver and was able to plot my track with Google Earth.

The new route is just under 1000ft in length, and pointed just about 030. I did this on purpose, as this direction is oblique to the noise source which is centered more in a 060 heading. I hope this helps null the QRN significantly. This is also the direct heading for W1/2/3, the most difficult region of NA to work from here.

When working in the jungle, I keep covered up from head to toe. This is to keep the spiders, spider webs, mosquitoes, and sharp leaves off my skin. Bug repellent barely works, and after 5 minutes, sweat has washed it off and the mosquitoes are clouding around me again. An old T-shirt covering my head keeps them at bay.

Jungle wear

I wear a white, heavy duty long sleeve shirt with gloves. The white is for visibility because I know a couple people who do hunt in an area adjacent to where my antennas are located. I wear an old pair of USCG ODU pants which protect me from stickers and other things that scratch. The head-to-toe covering helps protect me from wasps as well.

Can you spot the hornet nest?

The smaller “boonie wasps” are very aggressive and painful, but at least for me, their sting wears off after about an hour. The larger hornets, on the other hand, are less aggressive but pack a powerful punch. A sting from one of these is like getting hit by a line drive baseball, and it hurts for well over a week. They also have a habit of building nests in ferns, about 1-2ft above the ground where they are impossible to see until it is too late. Today I ran into one of those nests, but fortunately did not get stung. I beat the brush ahead of me with a 6ft piece of aluminum tubing to try to give myself some advance warning instead of stepping right into them.

Close up of the hornet nest. These guys are not aggressive but have a very powerful sting if their nest is disturbed

 

GoPro Hero2

I picked up a new toy this week – a GoPro Hero2 camera. The first thing I did is hook it to a long pole and take a bird’s eye photo of my Spiderbeam.

Looking north from about 50ft:

The Beverage RX antennas are all in the jungle in the distance. You can make out the 40m vertical to the bottom left, and also the 5el 6M beam hanging from a coconut tree to the right.

I’m going to have fun with this new toy!

New 80/160m antenna

My original 80/160m antenna has served me well since transferring here to Guam. It was configured with balanced “window line” as an inverted L on 80 and a top loaded TEE vertical on 160m. The top was at about 58ft, the highest I could go with the current mast configuration.

The problem was that the two top loading wires were not 180 degrees out from each other. They were more of a 120 degree separation, because of where the coconut tree end supports were located. This pulled the mast to one side, and the prevailing trade winds pushed it over even more. I attempted to back guy the mast, but since I had threaded the mast through the center of the tree, I could not get the support to the top and eventually the mast started to bend.

Eventually it got so bad that my kids named it the “Banantenna”.

Banantenna (aka banana-tenna)

Every year I like to try to improve the antenna system. This year, the project was obvious: replace the Banantenna.

The new mast is now taller, just under 70ft. It is much stronger. The top section is a 25ft long piece of bamboo, which is strong and plentiful. It is lashed to a section of aluminum boom, which in turn is telescoped into a 20ft piece of 2″ water pipe. The new mast is routed through the tree differently, and is much easier to put up and take down. This is important, especially during typhoon season.

Gone is the 80m inverted L and 160m TEE. The new antenna is a full 1/4 wavelength high vertical for 80m, which is top loaded for 160 with three top loading wires. The top loading wires are staggered 120 degrees and serve also to support the mast in the wind. Again, I used 450 ohm balanced “window” line. At the feed point, both wires are joined. At the far end, one simply terminates (this side is the 80m vertical), the other continues to the top support and three top loading wires (160m top loaded vertical). Essentially, I have two parallel verticals, separated by one inch (the window line). They share the same feed and radials.

New 80/160m vertical and mast
Looking up, you can see the bamboo mast section and balanced feedline radiator
Three top loading wires

The feed point has not changed. I still use a remote vacuum relay to switch a hairpin coil across the feed point when on 160m, this serves to match the low impedance 160m antenna to the 50 ohm transmitter. The impedance on 80m is high enough to be fed directly without matching.

Feed point configuration

The new antenna does seem to work better than the older version. Stateside stations seem to be hearing me better than previously on 160m.

 

2012 CQWW WPX CW – late posting

Back in late May I operated the WPX CW contest. Just after the contest, I submitted my log and got on a plane to San Francisco for work. I never got the chance to post anything about the contest.

Conditions last year were brutal, so bad that I quit just over half way into the contest. I was scared to death that the conditions would be just as bad, but they turned out to be great. 15m stayed open into Europe late and 20m was open all night long.

My final score, taken from the computer screen:

t was really nice to break 12 million points, but of course this score will drop significantly with log checking. This should still easily break the existing Oceania SOAB record, 9.1m, held by Bill K4XS (KH7XS).

The continental results showed a nice even mix of Asia, Europe, and North America:

After the contest, I went to visit Danny, KH2JU, who had visitors. J-P, OH6RX, and Harry WX8C operated multi single from Danny’s station. It was really great to have the opportunity to meet Harry for the first time and J-P again after many years – the last time was in 2002 at WRTC in Helsinki.

From left: OH6RX, KG6DX, N2NL, WX8C, KH2JU, KH2JU XYL