Monday, July 21, 2014

July 20, 2014 Six Meter Opening

This past weekend (July 19-20, 2014)was a flurry of activity in a short period of time. Company in the house had kept time before the radios to a minimum, but a short period Sunday afternoon more than made up for it.

A friend  had antenna trouble earlier in the week and I managed to take time off from visiting to run by his house and help him trouble shoot the problem. During the course of the visit, we talked about six meters and talked about a quick way to get an antenna up for at least listening on the band. The idea of a wire antenna was already on the table because of my somewhat success in using my 90 foot sloper as an interim antenna on six and the discussion turned in that direction.

We looked at how it is common practice to use a forty meter antenna on fifteen meters. The third harmonic relationship of those two bands means that a half wave antenna on forty becomes a 3/2 wave antenna on fifteen, matching fifty ohms rather closely on both bands. In fact, any half number of half waves will do the same.

Looking at his space available, it was determined that there was room for a 7/2 waves antenna for six meters, it turning out to be about 63 feet long. Interestingly enough, this also would make the antenna useful in the forty meter 'phone band! It was decided he would try putting it up in an inverted Vee configuration as is common for HF operation.

Sunday afternoon, he told me that he had the antenna up and it matched up pretty well without a tuner on six.. As I returned from a road trip taking our visitors back, I got a text from him, first saying he had worked a South Carolina station ( from his  Central Texas QTH) on six with good signals and that there appeared to be a contest on. Just a short time later he had worked 12 stations in 7 states. The top of the wire was probably about 30 feet up.

I checked the contest calendar as I settled back in and noticed that it was the weekend for the CQ World Wide VHF Contest...but it was ending just as I sat down. Since my friend had mentioned the band was open, I decided to tune through the band anyway, if nothing else to see if a few beacons were coming through. I also figured that if the band was really open, a few operators would continue to try to work some VHF DX even if the contest period was over.

Turned out I was right on both counts. Just tuning up from the bottom of the band up to the area where I often hear beacons ( 50060-50080) I quickly ran into an extremely strong signal from WZ8D, on 50067.25 indicated on the R-75 Signal was S-9, sometimes hitting 10 DB over S-9! Yep, there was a band opening! This was at 2106 GMT, just six minutes past the end of the contest.

The receiver was in the wide bandwidth, and I could hear another somewhat weaker signal adjacent, so switching in the 250 Hz filters, it was easy to separate out WA3TTS/B, another beacon on 50068.5 indicated, not quite as strong, but very respectable.

Over the next half hour or so, the following appeared in the reception log ( all times GMT)

2108 W8IF/B 50079.25 579 CW Beacon
2112 WD8CW 50098.2 559 CW calling CQ
2113 K8LEE 50077.9 589 CW Calling CQDX
2114 N5DG 50104.5 549 CW Calling CQDX
(very weak at times, deep fading and a flutter, almost buzz modulated-backscatter?)
2115 K4RX 50103.5 559 CW Calling CQDX
2121 AC4TO 50107 539 CW working another station
2123 AB5EB 50106.25 559 CW Calling CQ DX(fluttery)
2124 KB9AX 50106.5 589 CW Signing with another station
2129 KD8NYL 50130.2 57 SSB In QSO
2130 K4RX 50103.2 589 CW Calling CQDX
2133 WA9IOC 50094 579
2134 W9CPV 50093.25 569 CW
2135 WR9L/B 50074.4 579C CW Beacon
2136 W0FY 50074.4 579 CW Beacon
2137 K0KP 50073.4 589 CW Beacon
2141 K8TB 50065.3 549 CW Beacon
2142 W8EH 50060.6 579 CW Beacon
2144 W0ZF 50128.1 58 SSB
2147 KG9Z 50096.1 579 CW CQ

It might be worth watching the VHF publications and other blogs, because I heard some of the stations apparently working Europeans, though they were not audible to me. I heard at least two stations appearing to exchange signal reports with an ON station and one with an Italian.

It was also interesting to note that relatively nearby stations ( near in the overall scheme of things, not actually local in the Waco area) were obviously multi path back scatter signals with echo, flutter and almost a sound of being modulated by a buzz.
I continue to be intrigued about the idea of using long wire antennas for VHF. There is gain to be had and the multiplicity of lobes makes reception from various directions possible.  It can also allow operation or reception quickly without complicated antenna construction.  Not to say that it would equal stacked multi element yagis, but the inability to get those up should not be a reason not to get on the air or to listen. Feedline does become a consideration, however, as losses at these frequencies are higher and at least a fair match is necessary to avoid even greater losses. open wire line might be a consideration and experimentation is on tap for that here.

I would be interested in hearing from anyone else who noted this opening or others, particularly anyone in Europe who noted it or even heard some US stations.

This opening was particularly interesting because this week has been marked by a very quiet sun, few if any sunspots. All during the week, the upper bands have been poor or totally silent here, thought 20 meters has continued to surprise with openings to Russia and Asia in the 0200-0300 time period.

I hope to have more time to explore what is going on with the bands this week. This past week was filled with visiting grandbabies, and after all, this is “ just a hobby.”

Monday, July 14, 2014

Wake Me When the Band Opens

Wake Me When the band Opens
Sometimes we need to be awakened when the bands are open. It might not seem there is much there and it becomes easy to doze at the controls and just go off and do something else. Maybe we are just hearing the same old stations or maybe we get a little jaded and long for the “real DX” when there is still plenty to be had right in front of us. Maybe we just need to listen a little deeper into the noise. Sometimes it can be a matter of looking back over old waters that we thought had been fished out.

Such was the case this past weekend when C1AT, my second op, found the bands a little boring. The past several days—in fact most of the past week—had seen the low frequencies clobbered with QRN. Static crashes from thunderstorms had entered the headphones and were like a hammer that delivered well directed blows to the head.

So when the weekend came, C1AT suggested starting at mid day with a WWV sweep to see if the higher bands held promise. There was supposed to be a high level of solar activity toward the end of the week and if there were indeed blackouts perhaps the residual ionization might make the high bands better a few days later.

Starting the sweep at 25 MHz was not promising. WWV was a just audible carrier and no signs of WWVH. The 20 MHz stop showed a very strong WWV at S-9+ and very steady, indicative of good short skip. At that point C1AT yawned. OK, lets check 15 MHz. Hmm, S-9 +20DB with WWV on top and WWVH just barely audible behind. At this point C1AT put her head on her paws and uttered tose words,

“Wake me up when the bands open.”

Of course for real DX at midday in Central Texas ( 1700 GMT) it was hardly worth checking 10 MHZ, but I gave it a whirl: WWV was along at S-9+20 DB and steady, and just barely audible at 5 MHz, inaudible at 2.5.

A quick check of 6 meters, looking for some Sporadic E almost woke the cat up. There did not appear to be any activity to speak of and one beacon came through: W3DOG/B on 50017. As soon as she heard that call sign, she cafe a sniff and dropped back off. A swing though the phone band found one station calling CQ on 50135. A little adrenalin pumped when I heard “ Kilo papa 4” a few times with an incomplete call. Turned out to be a KP4/W3. Still DX by 6-meter standards, but short of entering the “ countries” column. And he faded quickly and disappeared, leaving a sea of white noise very conducive to snoozing.

A sweep of 10 meters saw little activity. Many beacons were there, but most operators must have been lulled to sleep by DX boredom. How could they? The band was obviously open to much of the US and the XE1RCS beacon on 28183.4 was quite strong. The somewhat chirpy but very familiar sound of the PY2WFG beacon was there on 29203.3. The West Coast was represented by K6LLL/B on 28203.5 almost colliding with him. And YV5LIX was very strong on 28215. There were other beacons audible from various call areas of the US, at least one other XE a VE7 and a few other Brazilians. Where were the “ live operators”?

Snoozing, I guess.

A trip to 12 meters found no signals at all. None! Fifteen was pretty light. A “7” on SSB along with a TG9 from Guatemala. Slipping down to the cw portion, at 1732 found a station involved in an obvious rag chew style contact, very strong, very steady. Was this another Stateside short skip station? Probably. C1AT snoozed on. But wait! When he signed, it was F6FPU! France with a good, strong, steady signal into Texas. The W3 station he was working was weak and warbly, sure signs of the band being very, very long.

But that was all. Further up the band, there were numerous strong US stations around 21050 taking part in the Weekend Sprint contest for straight key operators. NC1M was 599+20 DB! Maybe the W3 above had just had his beam turned toward Europe and had little signal toward Texas. Maybe C1AT was right. The eyelids were getting a little heavy from hearing the steady “ hiss” from the receiver undisturbed by DX dits and dahs.

Lets check 17 meters. A little excitement when an EA9 showed up with a little pileup on 18070.6, then CT8/DL5NUA on 18075.2 with a fair signal, followed by DL1MD...but then not much.

When one pond shows no fish, try something else. Lets go looking for SWBC stations. Its been awhile since we had done a good sweep of the higher SWBC bands in mid day.

Thirteen meters is the first stop. Will anything be there?

1758 GMT RNE 21610 S-9 Noblejas, Spain
1800 GMT WHRI 21600 S-7 Cypress Creek USA

And that was that! OK, lets look at 16 meters:

1804 (All GMT) VOA 17895 S-9+20db Greenville USA
1805 BBCWS(FR) 17885 S-9 QSB Ascension
1806 RNE 17850 S-9+10DB Noblejas, Spain
1807 WRMI 17790 S-9+30 DB Okeechobee, USA
1809 RNE 17755 S-6 Noblejas, Spain
1810 RNE 17715 S-9 QSB Noblejas, Spain
1812 AIR (!!) 17670 S-5 QSB Dehli, India

Ah, one little jewel. The lists show this last one to be a non directional service. Maybe a yawner to some, but it made at least an interesting entry. The rest of the session was spent with a sweep of 19 meters that did not turn up anything earth shattering, but was still useful to stay familiar with the band. There was one nice logging at 1818 on 15650 from Greece and another of the VOA station in Botswana at 1820 on 15580 that took a little digging to hear well enough to ID, peakinga bout S-5. The rest were routine except for Radio Sultanate of Oman at 1835 on 15140 with a very nice signal.

Not earth shattering DX, but still a fun couple hours in front of the radio. And yet another lesson in finding DX when the band does not appear to be exactly hopping. Even afer all these years, signals from Botswana and Oman are still pretty exciting.

And C1AT? She said to wake her up when Masterpiece Theater came on...

Sunday, July 6, 2014

Flashback: The Doomed Beam Antenna

A few months into my Novice amateur radio career, I was beginning to feel the nibblings of the DX bug pretty bad. A magazine article and a project in the ARRL Antenna Book had me anxious to try building a small beam antenna. The antenna had a small boom and a moderate amount of gain and appeared to be something we could build at home. It was thus that at age 13, my first beam project lived, and died.

The antenna was a two element phased affair known as the “ ZL Special”. I am not sure where the name came from but it brought forth visions of working many of them on fifteen meters. There are literally dozens of articles about the design on the internet now, but then all I had was a few paragraphs in the ARRL Antenna Handbook ( 1961 Edition!)

The antenna is basically two folded dipoles spaced a short distance apart and connected with a transposed phasing line. The articles about it indicated that this resulted in a 135-degree phase difference between the elements. It can be built like a small two element yagi, and fed directly with 52 or 75 ohm line.

I had planned to make it with two pieces of TV twin lead and just hang it in the air, then wondered aloud if it could be made with a wood frame to support the elements. My dad once again jumped into the project and we soon had a frame built out of material from his carpenter's equivalent to a parts “ junk box”. He had material stored that was left over from numerous past projects and remodel jobs. It was to be a lesson in antenna construction for both of us.

It was decided the antenna would be mounted on one of the wood masts for my longwire. The longwire I had was suspended between two wooden masts consisting of 2X4's using rebar as steep angle guys.( My dad never built anything half-way. Those masts had triangular concrete foundations) It would be supported by a short piece of water pipe that would be attached to the mast with a pair of angle iron brackets that would be placed around the mast rather than weaken the wood mast by drilling holes through it. The angle iron came from an old bed frame that turned out to be a source of hardware for a number of antenna projects over the years!

The boom for the antenna was only about five feet long and was to be a 2X4 with a threaded floor flange being the means of attaching it to the water pipe support. The elements would be the twin lead supported by thin rippings of redwood. The twin lead was tied to the supports with monofilament fishing line at about six inch intervals. It was fed with 75 ohm twin lead. This and all my antenna projects were low budget, all built with what was available. The 75 ohm twin lead was two cents per foot in 1963.

The antenna masts were both already designed to be tilt-over affairs so attaching the antenna assembly was not too difficult. It took us the better part of a Saturday to put the beast together and get it into the back yard. At that point we learned just what “heavy duty construction” means.

Dark was falling when we were finally ready to raise the antenna. In order to lift all the weight of the wood mast, we got on the roof to pull on a rope attached to the top of the mast. W had the mast sitting it up on a sawhorse to have it off the ground a bit and to give us a little better pulling angle. Once we got it vertical, it was a matter of putting in a locking pin through the lower part of the mast and reattaching the guy lines. The masts were guyed with pieces of iron reinforcement rod such as is used in concrete and came down within two feet of the base of the mast, making the mast almost like a small tower. My dad really did not like the idea of wire guy lines cluttering up the yard.

There was no rotator for the antenna. We had a light rope dropped to allow the antenna to be pulled in different directions then tied off. It was about 22-feet off the ground. The brackets holding the mast were larger than the mast pipe with a sleeve pipe over it, allowing the antenna mast freedom of motion. The lower of the two brackets supported its weight on an old wheel bearing. My dad was pretty resourceful about such things.

There was little wind when we got the antenna in place. It was also about dark. It would be the next day before the trouble showed up.

Because it was after dark, the 15-meter band was dead and devoid of signals with which to test the antenna. It tuned up fine, actually loading up much easier than the longwires did on 15 meters. It also showed much less power line noise than did the wires. That might have been because it was directional and was turned at right angles to the power lines.

I called a friend of mine across town to get on the air to try it out. I started out with it turned toward him. He was across Waco from me, probably about 12 miles away by air. The initial word was good. I was much stronger there than I had been on my old inverted V and somewhat stronger than on the longwires. Turning the antenna 180 degrees showed a good drop in signal and turning it 90 degrees to him had me almost disappearing. The initial feeling was that it was working well.

The big test would be the next day. I had a weekly schedule with a station in the state of Washington and that would tell the tale of whether the antenna would really work better than what I had been using. Images of large numbers of DX QSL cards began to appear in my head.

The next morning, the wind was up a bit. As we backed out of the driveway to go to church, my dad and I noticed that the elements were hopping a bit in the wind. He noted that they appeared to catch the wind quite a bit.

By the time we got back from church, the wind had picked up quite a bit. I went out back to try to turn the antenna to the northwest to set up for my schedule. It was a real fight getting it swung around. Winds were up around 20 to 30 miles per hour by that time and it was obvious that something about the wood elements was really catching the wind. The ends were moving a foot or more up and down continuously. The wood mast was creaking and swinging within the constrains of its guys.

About that time, my friend had driven over to see what we had built and as he and my dad came out it was obvious that the antenna or mast might not survive. Rather than loose the whole thing, it was decided to try to take it down.

That decision was almost a disaster in itself. It took all three of us hanging on ropes to lower the mast that by that time was bucking and twisting wildly. We got the thing down, took the brackets off the mast and raised it back up where it seemed to heave a sigh of relief at just holding up the wires again.

The doomed ZL Special never came up off the ground again. Within days it was disassembled and the twin lead went into my own parts junk box for use another day. Thus were lessons learned at an early age about light weight antenna construction and the effects of wind loading!