Sunday, August 16, 2015

DX Seasons Change

The seasons are changing and days are getting shorter. Already the DX opportunities are changing, not only for the yearly seasons, but for the longer term cycles as well.

June 22 was the longest day of the year, and already the days are getting noticeably shorter. My morning drive to work has gone from being in full light to sun in the eyes ( I catch this both coming and going, driving east to work in the morning and west going home in the evening). This past week, the sun has been right on the horizon as I pull into the parking lot of the television station where I work.

The past couple of weeks I have been noticing that some of the more distant groundwave stations I listen to on the radio in the pickup have been showing signs of increased co-channel interference. Even as the sky has already been fairly light, the distant stations have begun to show up, even on the lower parts of the dial.

The old familiar “faces” are beginning to show up, along with a few surprises. The first of the real DX stations to appear here were KOA from Denver on 850 and KSL from Salt Lake City, Utah on 1160. The 1690 from Denver has sort of there on first check, but still being on night time power and with daylight still showing here was not that readable. The first two were predictable since they both run 50 kw and have real powerhouse signals anyway.

Stations to the east are not coming in that well yet, being in even more sun than I am at my location, though some of the fairly close in stations are a little stronger. The KMOX signal on 1120 from St Louis is audible behind the daytime only station that has come on in recent years from the Austin area. KWKH from Shreveport on 1130 was in. KOKC on 1520 from Oklahoma City was audible but being covered by the daytime only station from the Houston area that relays Radio China International programs.

KOKC is a bit of a special case. They are still on reduced power day and night because of damage to their antenna system from a tornado. They had just completed a refurbishment of their three tower directional when the system was all but destroyed by the storm several months ago. Two towers were destroyed and one was bent and had to be taken down. They were off the air for several days while that was done.

As an aside, they might be a special DX target for medium wave listeners as they transmit non directionally night time with I believe 10 kw during the rebuild process. While some listeners normally in the main lobes of their directional pattern might note them down in signal strength, others in other directions might be able to hear them in areas where they might not usually be audible at all.

As we get toward the later parts of the month, other DX possibilities appear. Stations operating with full daytime power will start to skip better as darkness extends later and later. While their hours of operating with day facilities takes into account these changes, there are still some times where those signals will begin to travel greater distances than even predicted.

Other impacts on the dial have really shown up on the higher frequencies. XERF on 1570 now has an almost local signal strength level here during my morning drive ( 6:45 AM local time, or 1145 GMT). The other Mexican stations on 1220, 1190, 1050, 990, 940,900, 800 and 540 that are usually very strong at night have begun to appear even over some of the more distant groundwave stations that are already on daytime power here in the Central Time Zone. Even the stations on 1000, 1030 and 1060 have been audible. The 1030 from Mexico City has some mornings covered the 50 kw KCTA from Corpus Christi which is usually audible even on groundwave from over 200 miles away.

It is also interesting to note that during this time of flux in morning prop, the conditions and specific direction that the band appears to be open seems to shift from day to day. Some mornings the Mexico City 1030 will be in strong, others it will not. Also, it should be noted that while all of the Mexican stations mentioned have been coming in, the ones higher on the dial are still much stronger than those down low. That will change dramatically when the morning drive is in full darkness.

It should also be noted that 1060 now offers a new DX possibility for many BCB DX-ers in the southern US because it appears that heritage 1060 station in New Orleans is now off the air and may not be returning. This is a real tragedy for those of us who grew up in the sixties listening to legendary WNOE. Of course in recent years, the station had different call letters and a much different format than the rocking Top 40 tunes it played back in the day!

For those who listen in an around sundown, the same kind of thing can be noticed, but with stations from the other direction. Stations from the east and northeast will be coming in a little “ early” while still on their daytime facilities. Here, the Cuban 1620 has been showing up under the near local WTAW along with US stations in the southeast. The Caribbean Beacon has also appeared a bit before sunset on 1610. However, the Cuban on 530 has not made a pre-sunset appearance yet. The 1540 from Warterloo, Iowa has appeared behind and occasionally over the 1540 in much nearer Ft Worth, and Nashville's WLAC on 1510 has begun showing up over much nearer, low powered daytime only stations on that frequency.

The real surprise here has been on 800 khz. I am not sure if something has changed with antenna systems at the station in Windsor, Ontario or if in years past I just never noticed or just wasn't in the right place at the right time. But there have been times just before sunset and just after sunrise that CKLW has been audible under XEROK. Particularly in the time just before sunset CKLW will completely override XEROK, which is well to the west and more in sun than its neighbor to the north.

For others, similar opportunities come this time of the year. I am not sure how many stations in Europe operate with reduced facilities at night, but the opportunities for extended prop at sunrise and sunset exist. With some AM stations being shut down, the DX opportunities are increasing anyway. It would be good to hear from some of you with your observations of sunrise and sunset DX. It should probably be the subject of another column, but the opportunities for some really long haul BCB DX in southern Europe should be increasing daily with some long time stations disappearing from the dial, while stations in Africa and Asia still on. I am not certain about the status of many of the high powered AM stations in the former Soviet Union nations or in Russia itself.

While the changes in the yearly seasons have been marked in the DX log here, so have the changes in a much longer cycle of seasons: The eleven year sunspot cycle. On the amateur bands this weekend ( August 15 and 16, 2015) there were three regional radio contests. Monitoring the upper HF bands of ten and fifteen meters, it was very obvious that the sunspot count and solar activity level was down.

Checking the WWV frequencies at noon local time, or 1700 GMT, the signals at 15, 20 and 25 MHz were all S-9 and steady, while the 10 MHz was S-9 +10 DB with 5 and 2.5 MHz inaudible. Over the next hour, no contest signals were heard on ten or fifteen meters. On twenty meters, US stations were all strong and steady and while some east coast stations were heard working Europeans, none of the Europeans were audible here in Texas. The only station heard outside the US was from Mexico.

By mid afternoon or 2200 GMT a few Cubans were heard, and by 2240, some Brazilian stations active in the CVA contest were heard. As the afternoon wore on, a few stations from Spain and Southern Europe started coming through, though not with much strength. As the clock moved through 2300, many South American stations began coming through. Numerous stations from Brazil were heard.

A switch to forty meters showed the first station from Brazil come through about an hour before sunset, at 7:03 PM local time or 0003 GMT. As the hour wore on, signal strength of the Brazilians active in the CVA contest grew stronger and stronger, many up to S-9. While there was also a Russian contest going on, none were heard here by the time I turned the radio off at 10 PM local or 0300 GMT.

A quick check of 80 meters at 0230 GMT showed the Brazilians coming in there, too. Some were displaying pretty good signals with PY5XH at S-9!

At this point a check of WWV showed 2.5 MHz at S-9 +20 DB, 5 MHz at S-9+30DB, but 10 MHz down at S-5 with WWV and WWVH about the same strength. The 15 MHz signals were even weaker with both stations coming in equally. Nothing was heard at all at 20 and 25 MHz.

Just as the seasons change through the year, the seasons change with the sun. Through the year listening habits have to change to match the conditions, at various times in the sunspot cycle “seasons” need to change to match the conditions. Some would say the bands are just “ terrible” when in fact, the activity just shifts to different frequencies. In some cases, time spent listening might need to be adjusted along with what frequencies are tuned.

I have often compared DX-ing with fishing, and here I will do it again. With changing times and changing conditions, the place to “drop the hook” changes, too. Some fishermen will say when the weather is hot or the weather is cold, or conditions are this and conditions are that that the fishing is terrible. The truly experienced fishermen will still find a way to catch fish. They may go to different places or go fishing at different times, but he will still catch fish.

The same with the “ Compleat DX-er”! Happy listening and good DX!

No comments:

Post a Comment