Wednesday, November 15, 2017

Using a Software Defined Radio (SDR) on the FM Broadcast Band to Foretell 2-Meter Band Openings


Background

    I have always enjoyed the DX’ing hobby. It started for me during the Fall/Winter of 1961-62 when I suddenly started hearing “Clear Channel” AM Broadcast stations on a 6-Transistor radio. Then living in Houston, Texas it wasn’t too uncommon to see a central, south or southeast Texas TV station on our Rabbit-Ears sitting on top of the Black & White television.
    In the early 70’s, I put up a good outdoor log-periodic VHF/UHF-TV/FMBC antenna, a Citizens Band 4-element Yagi and a rotor to turn it.  My DX’ing focus changed from medium and short waves to the higher frequencies (11 Meters, VHF and UHF).  Besides living in Tropo Heaven (Houston), I started to experience some great Sporadic Es on TV Channels 3-7 and correlated it to activity on CB and Ham Radio 10-Meters.
    In 1978, I had moved to Fort Worth, Texas and by 1979 finally became a Ham. Of course, 10 Meters was my favorite HF band.  A few years later (1982), an interest in Amateur Radio satellites helped me acquire an all-mode 2-Meter transceiver. Once I worked a couple of Tropo openings and my first 2-Meter Es opening, everything in my Ham Radio life changed.
    I put back up the V/U/FM Log-Periodic and hooked it up to my old 13 inch Black/White Zenith TV (used as a monitor for my Timex/Sinclair Satellite Tracking computer). I actively began monitoring TV reception to use it as a tool to gage whether a 2-Meter DX event was going to occur. I also started using my car/truck radio to monitor the FM Broadcast Band.  Later on, I added a 4-inch B/W TV to the truck attached to my 5/8 wave 2-Meter vertical whenever I travelled.
    I was able to correlate events on Lower Channel TV and FMBC to Es openings on 2-Meters.  I could operate 10 & 6-Meters and look for shortened paths, including backscatter.  I could also observe TV and/or listen to FM and do my best to identify what I was seeing or hearing.  After a few openings, I learned that if I saw and identified a Channel 6 TV station or a FM station on Sporadic Es, if 2-Meters opened, it was to that same general area of the TV or FM station.  A few times, exactly to the place I monitored.  I used it to my advantage. For most of the first 5 years on 2-Meter SSB and again for a short term in 1990-91, I ran 30 watts out on 2-Meter SSB.
    Most good things sadly come to an end.  Living in Dallas/Fort Worth area, I saw it grow from 3 to 6.5 million people. So did the number of FM broadcasters multiply over that period.  A number of outlying town’s FM stations expanded their coverage.  Before, the vast majority of transmission towers were located to my south-south-east. A few new ones were now to my northeast. The final insult was the local PBS affiliate (KERA) pulled out an old approved license for TV Channel 2 (UNT or N. Texas State) and killed that frequency for monitoring.  Channels 2, 4, 5, and 8 were now occupied locally. KERA-2 was a failure and sold it to a Gospel of Wealth religious organization.  In the end, HDTV took over and most stations moved to UHF.
    I took a hiatus from VHF/UHF DX’ing from 2008-14, pulled down the tower and antennas, retired in 2014 and moved to the upper desert of Arizona.  I set up shop in Arizona by the beginning of 2015 and starting working on new VUCC’s.

Now in Arizona
    Unfortunately, I moved here towards the second peak of Solar Cycle 24.  Despite what others tell you, this solar cycle had an adverse affect on VHF propagation. 2 Meter Es openings have been far and few between. 6-Meters has had good moments from time to time, but has not had a long period opening (24 hours) in many years. 2015 was okay, 2016 was a bit of a stinker season and finally 2017 has seen a very good improvement despite a few quiet periods.
    Trying to work VHF Es can be challenging at times here in Arizona. The best distance for single hop Es tend to be in low Ham Weak-Signal populated Grid Squares. Timing to populated Grids has been way off so far. Much of my Es DX has actually been Double-Hop Es. This year, my average distance for a 10-Meter Es PropNET capture (1,883) was 300 kilometers longer than the next closest average participant. Of all the major PropNET participants (23), my captures were 500 kilometers longer than the overall average (1,348).
    For quite a number of years (late 90’s) on the Internet, I had visited DX World operated by Bob Colyard of New Jersey (www.dxworld.com). Bob had set up various lists for the DX enthusiasts. Hams from HF to UHF, special modes, and SWL’s all had a List to post their latest DX accomplishments. I have reported many a 2-Meter Es, Tropo and Aurora opening, as well as 6-Meter Es and F2 openings before reporting to other sites such as DXSummit, DXScape and DXMaps became more common. Thanks to well known VHF DXer Pat Dyer - WA5IYX, the TV/FM Skip Log ( http://dxworld.com/tvfmlog.html ) became a popular place to share various VHF and UHF propagation events.  The genius that Pat was also led to many a discussion about Es.  I used it from time to time to gauge what was happening on VHF and once I moved to Arizona, I shared with the others what I was observing here.
    Once analog TV ended in the U.S., followed by Mexico and dwindling in Canada, the Logger was concentrating more on FM Broadcast Band DX.  I felt a little disadvantaged here.  I can DX with the best of them, but other than my radio in my car I did not have a receiver that could decode FMBC RDS and PI Codes. When you are working DX on 6-Meters and trying to raise 2-Meters from the dead, it is a little tough trying to identify FMBC stations when your attention is on other matters.

Looking For Solutions
    Software Defined Radio has really made its presence known the past few years. Technology works wonders. It has happened so fast, I haven’t been able to keep up. I had seen advertisements for a number of devices ranging from $150 to $450.  Being retired and wanting to put my money behind more beneficial things such as Ham Radio, I really didn’t want to spend a lot of bucks on something used a little.  Hams are notorious for spending themselves into debt for things they don’t use or get that much out of.  I have always done my best to squeeze blood out of a turnip.
    Towards the end of the 2016 Spring/Summer Es Season, I looked for a SDR on Amazon. Cookies got me and started seeing ads for them whenever I visited a website that allowed cookies.  Shortly after, I saw an ad for a RTL-SDR for $17. What did I have to lose?  I purchased a couple of other items I needed to get free shipping (the wife refuses to join Prime).  A few days later I had the RTL-SDR.


    Instructions for these devices are a little short, but if you are a tech-nerd you figure it out. I had 4 old computers (two XP, one Vista, and one Windows 7) and quickly found out that the Windows 7 laptop was the best computer to use.  I also had to order a couple of SMA feed-line connectors, one with a female F-Connector and one female BNC. As for software, SDRSharp was used when Windows 7 was the operating system. I liked the ability of picking up RDS and software that is free.
    I had a myriad of antennas to plug in and struggled with which ones to choose. I settled on a FM-Turnstile (crossed dipoles) about 20 feet up the tower and hoped for a high MUF before the Es season ended. Luckily, a high MUF occurred. I was absolutely stunned what I was picking up. It was a good late season Es opening (8/05) and nearly every FMBC frequency on the low end was active. I did pick up several Louisiana and Texas RDS call and slogan identifications. I never expected that result with a multi-directional antenna. I tried out the log-periodic, but by then conditions had deteriorated.
     I spent the fall and winter trying the SDR on other frequencies (Aviation) and several Ham bands, but I just got more enjoyment on FMBC.  I did acquire a refurbished Windows 7 Pro desktop to operate a computer to Ham Rig interface along with the RTL-SDR. I was active this year on 10-Meter PropNET (last year WSPR) and wanted the flexibility of doing my automatically controlled digital station and the SDR on the same computer. My Log-Periodic has an advantage over the turnstile with forward gain and being able to null out strong (semi)local stations.  
Two Dell Desktops. The RTL-SDR overwhelmed by cables.
45 year old Archer V/U/FM-125 Log Periodic (UHF elements removed). A FM Turnstile (omni-directional) antenna is mounted about halfway up the tower.
    As Radio Shack was closing, I picked up a higher quality Antenna/Cable switch for both FM/TV antennas and placed it behind the desktop computer where the RTL-SDR was placed.  With a lot going on in my personal life and little time, I got it together as best I could for the 2017 Spring/Summer Es season.

Editorial Comment
    First of all, there are a number of excellent devices, and I would expect by the cost of these that they will outperform the RTL-SDR.  In addition, there are a number of software packages at a cost that maximizes their capabilities.  I do this for one simple reason, to help give me an edge to maximize my goals and pursuits in Ham Radio Weak Signal activities. I place my attention and my fixed income finances on that first.
    This activity using the RTL-SDR comes secondary and does a support role.  I chose the RTL-SDR device because it was inexpensive, the SDR Sharp software because it was free and I already had the outdoor antennas in use for DXing over many years.

This can be done better, but I argue it can be done as well as cheap.☺



Location:
Dewey, Arizona east of Prescott in the Lonesome & Skull Valleys
Grid Square DM34un
Elevation 4720 feet



First FMBC Es Event – August 5, 2016
The RTL-SDR was plugged into my Windows 7 Toshiba Laptop and the FM Turnstile hooked up.
Four (semi)local FM stations are appearing. 93.9 Flagstaff @ 51 miles, 94.3 Chino Valley @25 miles, 94.7 Prescott @ 12 miles (behind a mountain peak) and 95.1 Sun City West @ 23 miles  & 41 kW.

This is what a quiet band looks like from my home in central Arizona.

The same spectrum shown on Steroids during a high MUF and intense Sporadic Es opening.
Identifying the Early Signs

Sporadic Es usually show up on 10-Meters first. The easiest way to detect them is to listen for CW beacons between 28.2 and 28.3 MHz. Today’s new Ham tends to not copy CW very well. If so, use a computer to read them. There are real-time propagation reporters called CW Skimmers and show there spots on sites such as DXMaps. But unless you live close to a Skimmer, there is not much of a guarantee for your conditions. Active SSB chatter on the phone frequencies tends to show up later into the opening. Another way to know of 10-Meter openings is to capture PSK31 PropNET transmissions on 28.1186 MHz.  I have been active with them almost 15 years.

Once 10-Meters has been open consistently for around 15 minutes, you should be checking out 6-Meters. Like 10-Meters, there are a large number of beacons between 50.05 and 50.08 MHz. You can also listen to the SSB call frequency 50.125 MHz and up in frequency to 50.200.  A little troubling this year was a large increase in WSJT digital modes (FT-8 & MSK441). Yes it makes easier to DX QSO’s, but it really removes the excitement of exchanging a signal report, name and QTH by voice or CW. Once you notice that the path is getting shorter in distance then it is time to be watching for opportunities building to 2-Meters.

Here is where using this SDR device helps. One can visually see on the software spectrum to what Es are beginning to do.  First of all, be familiar to where local and semi-local stations are located. Use online sources such as FMFool.com, FCC FM Query or FMLIST.org.

I am blessed to be located in an area in which the major population centers (Phoenix & Tucson) are to my South to Southeast.  My VHF DX interests are in other directions. On this screen, the closest FM station (92.5) is weakened by hills and a mountain.  The others are 50-60 miles away.

Example of a normal FM Broadcast Band with no DX.
As the MUF of Sporadic Es increases, the incoming Es signal is full of rapid fading.  It is easily identified on the waterfall of the software, SDR#. The in and out fading signals appear as beads on a bracelet.
Weak Es signals begin to appear on 91.9, 92.7 and 93.3 MHz. A second signal is also appearing with local 92.5. This opening appears to have a small footprint.
Sometimes the beginning of an Es opening shows more opportunity. It might be a larger coverage footprint or a more populated area.






On these examples, nearly every FM channel is showing a growing Es opening.
If the Es opening continues to develop and intensify, the waterfall will show the resulting stronger signals.



The rapid fading conditions are still evident on strong signals.  Once signals approach 15 db above the noise floor, you have a good chance to decode RDS and PICode information.
Once you identify a FM broadcast station, begin to concentrate your 2-Meter efforts in the direction. My experience has been throughout the years that if and when 2-Meters opens, it will be in that direction and many times to the specific area you heard on FM broadcast.

A good sign in a FM Broadcast band Es opening is the stabilizing of conditions. Fading is less and the waterfall looks more like locals or Tropo. As the amplitude increases, it is time to see what the upper part of the FM band looks like.







These screen prints show a stable Es opening. Fading is much slower to non-existent.  It is time to look at the upper portion of the FMBC band and call on 2-Meters.
Looking at the lower end of the FMBC band (88-96 MHz) became addictive many times. Being the first year using a SDR, I was having so much fun watching it develop that I was ignoring the top part (104-108 MHz) of the band.




Once you see openings at the top part of the FMBC band, the chances of having Es conditions on 2-Meters really improves.  By now you should be sending CQ on 144.200 MHz and listening for others. Conditions here can help you be ready on 2-Meters.
Recognize and identify the FM stations as quickly as possible. Have a website, such as DXWorld-TVFM LogFMList or the Worldwide TV FM DX Association to help you narrow down the choices.
Once you identify a station, look for the distance between you and further identified stations becoming shorter in distance. This indicates a rising MUF. Once Es make it to 2-Meters, the chances are that it will be at the farther location you first identified.
Example: From here in Arizona, I hear and identify a Seattle WA FMBC station. Minutes later, I hear and identify a closer Portland OR FMBC station. The 2-Meter opening more than likely will occur around Seattle WA.


I cannot promise you great results, but I can assure you that being aware of these conditions and using these methods will improve your chances of working great distances on 2-Meter SSB next Es Season.


2017 Spring/Summer FM Broadcast Catches with the RTL-SDR

Monday, September 11, 2017

10- Meter Sporadic Es Have Returned

A Review of the 2017 Spring/Summer Sporadic Es Season on the 10-Meter Amateur Radio Band

At the end of 2015, I wrote an analysis on the affects of Solar Cycle 24 on the Spring/Summer Sporadic Es season.  (http://ka5dwipropagation.blogspot.com/2016/01/how-solar-cycle-24-affected-10-meter.html) The lull between Cycles 23 and 24 was the longest in modern radio history. During those years (2005-2011), Es propagation was exceptional. In particular, there were many multiple-hop Es opportunities and on many occasions good openings would occur late into the night and into twilight.
By 2011, Solar Cycle 24 finally had taken off and it was apparent that it affected Es conditions. By the 2012 season, activity had declined sharply. As solar activity remained active and peaked twice, in continued hold down good Es propagation for several years.

This Solar Cycle (24) has been what I call anemic. It was one of the least active cycles since the early 1900’s and the lowest in radio’s history. It was foretold by Jim Kennedy, K6MIO/KH6 in 2011 at the Central States VHF Society Conference. The magnetic north and south poles of the Sun swap as part of a normal solar cycle. For Cycle 24, these poles were out of sync and to expect a low and poor peak of the Cycle. Jim was right on the money. There was no 2-Meter Aurora in the southern half of the U.S., and I know of no FAI reported on 2-Meters either. 6-Meter F2 was almost non-existent.  There was some 6-Meter Trans-Equatorial propagation, but nothing close to what was experienced during Solar Cycle 23.
  
What was unexpected to me was that Geomagnetic Activity continued to increase after the Cycle peaked. I am not a Physicist, but I believed this increased activity kept putting a lid on a return of Es after the first Solar Activity peak (11/11).  After a disappointing 2016, a few out there wondered if Es propagation was a thing of the past. There we some moments during that Spring and Summer that looked promising, but nothing lasted over a period of days.
Over the Fall and Winter of 2016 into 2017, solar activity started to drop like a rock and geomagnetic activity looked to be declining. I anxiously waited for an improvement. Es did not disappoint.
The end of Solar Cycle 23 and the beginning of Cycle 24 occurred in 2008. It took 6 years to peak, normally occurs in 4-5 years. By late 2011, F2 propagation became common place on 10-Meters during the Fall, Winter and early Spring,
  
Somewhat puzzling was the rise of geomagnetic activity (measured as Ap Index). Confusing was a decline in 2014, but understood as the peak of solar activity (solar flux & sunspot number). It was more active in 2015, peaked and remained active for 2016.

Notes for All PropNET Activity Charts
1.  All charts reflect all North American PropNET PSK31 captures on 10-Meters during the recognized Spring/Summer Sporadic Es season (58 days each side of the Summer Solstice). Other continent PropNET captures were removed unless it was an Es capture of/from a North American PropNET participant.
2.  All captures considered non-Es (F2, TEP, Ground Wave, or Scatter) were removed from this analysis.
3.  Any captures that were not verifiable by a legitimate Callsign or grid-square were also removed.
4.  All 10-Meter captures used occurred from UTC dates April 25 through August 15-18, approximately 8 weeks, plus a few days each side of the Summer Solstice (June 20-22).

So what has happened the past nine years to 10-Meter PropNET Es captures?
Once solar activity increased, Es propagation began a slow decline in 2010. Once solar activity took off, it dropped rapidly and reached its bottom in 2014 the peak of solar activity for Solar Cycle 24.  Recovery has been very slow and finally returned to much better levels this year. The increase was dramatic, just as the decrease between 2011 and 2012.

Hourly Activity Patterns over the Years

Each year is different somewhat, but activity generally shows a dual-peaked diurnal (daytime). The solar and geomagnetic active years (2012-2016) are quite distinguishable. 
The hourly chart is shown in Sunrise, to Sunset, to Evening, and into Twilight in order to better show peaks in activity.  In North America, the Sun rises on the East Coast during the 10th hour UTC, and sets on the West Coast around the 3rd hour UTC.  It is solar noon along the Mountain/Central time zone border at the 19th hour UTC.

Regardless of year or solar affects, Es activity soars once the Sun rises and peaks just after mid-morning. Most years, this is the best time for Es.  Activity declines as Noon passes, but peaks again a couple of hours before sunset.  Once the Sun sets, Es rapidly decline.

Dramatic Rise of 10-Meter Es in One Year – 2016 vs. 2017

The Sunspot Numbers and Solar Flux finally started to decline more rapidly in 2016 and again into 2017.  In fact, the rate of decline was much greater than what was experienced between Solar Cycles 23 & 24.  Geomagnetic activity was not declining at the same rate. I knew that the year would be better, but I just did not know how good it would improve.
A greater than 2½ increase in activity is something to not recognize. This was greatest change between years since the decline from 2011 & 2012.  The rate of growth for PropNET captures was far greater than Non-PropNET, an indication that the lack of conditions the past few years has run off many 10-Meter PSK31 operators.
Due to the lower total count, the number of hours active does not show the dramatic rise in activity. Note that the number of hours active increased from less than one-half of the day to two-thirds.  To put it in terms of the Spring/Summer Es season, in 2016 Es were confined to daylight an hour and a half after sunrise and before sunset. In 2017, it extended an hour before sunrise and an hour after sunset.

Intensity per Open Hour

I learned in my past analyses from 2005-2011 that as active hours increased, so did the intensity of that active hour.
There were near 600 more Es active hours in 2017 than 2016, with an average of 49 captures per active hour rather than 19.

Daily Activity

During the lean years and peak of Solar Cycle 24, it was extremely difficult to determine the beginning and end of the Spring/Summer Es season. At the traditional beginning (last week of April) and its end (middle of August), high solar activity had a strong affect. Between, it was difficult to determine the peak of the season (the week of the summer solstice).  By 2016, consistency in Es propagation seasonal daily patterns finally began.
By 2016 a more standard pattern of a typical season was evident and a polynomial trend line could be calculated. Despite the return to this pattern, there were a number of days in which little to no propagation occurred.

Note: The scale of this chart is 3 times greater than the 2016 graph.
Despite a slow start, each day of the entire season was greater than the prior. 

The polynomial trend line finally followed what had occurred in past good years. This was that the season actually does not end by mid-August. It actually ends at the end of August.

Active Hours for Es Propagation

In 2016, the influence of the Sun was still evident. The season started off well, but failed to be more intense towards the Summer Solstice. The end of the season turned out to be highly productive compared to the traditional peak (solstice).

In 2017, Es became much more productive. There were more numerous 24 hour active days and many over 20 hours. This had not been seen since 2011.

Cumulative 10 Meter Captures

The following charts closely display actually how many 10-Meter captures occurred each day of the season and at what rate.
For 2016, the average number of 10-Meter captures was 213 per day. The period from 6/12 through 6/24 saw higher rates. The remainder tended to fall short.
On the other hand, 2017 the average number of 10-Meter captures was 781 significantly higher. The most productive time began again on 6/12, but this year lasted until 7/9. The season ended very strongly as well.

Hourly Activity and Intensity

The following charts show total hourly activity for the 2016 & 2017 Es season through North America. They are displayed in sunrise, to sunset, to evening, to twilight order to best display the diurnal (daytime) pattern.

Regardless of year or point in the Solar Cycle, the dual-peaked diurnal in prevalent most years. 

Note: 2017 scale is 3 times larger than 2016. Each hour of the 2017 season was higher than 2016 and was very similar in pattern. 
There were 116 measured days in this analysis. In 2016, most of the daylight hours were open over 50% of the days.

In 2017, most of the daylight hours were open 75% of the days.

Distribution of PropNET Participants
Listed below is 99.5% of the North American 10-Meter PropNET catches.
Ratio
Rank
Call
Grid Sqr.
Captures
Captured
Total
Capt/Captd
1
WD4RBX
EM84NN
18623
5113
23736
3.64
2
KE4GWW
EM71HF
12111
10796
22907
1.12
3
VE3GTC
FN25IG
3185
17551
20736
0.18
4
W5LA
EM32VN
8043
11765
19808
0.68
5
W2EV
FN03XD
6342
11959
18301
0.53
6
KF9KV
EN52ET
6238
5956
12194
1.05
7
KD0IOM
EN41EX
6666
3633
10299
1.83
8
KD4IZ
FM19OO
5355
4042
9397
1.32
9
WB8ILI
EN82PQ
4375
4013
8388
1.09
10
KB1JDX
FN41BT
5401
1259
6660
4.29
11
NC5O
EM12PX
2274
4375
6649
0.52
12
KA5DWI
DM34UN
2683
1588
4271
1.69
13
NM4V
FM06QR
3248
56
3304
58.00
14
KI7J
DM42OF
321
1745
2066
0.18
15
KE6AJE
CM98AH
1227
623
1850
1.97
16
AD7LL
EM75ND
1319
492
1811
2.68
17
N6OA
EL99EP
1122
422
1544
2.66
18
ND6M
EM55TC
342
626
968
0.55
19
W6CGH
DM13BR
271
591
862
0.46
20
KF2AT
FN30AS
81
508
589
0.16
21
KC9NBV
EM69OE
406
131
537
3.10
22
K7EK
EM77AT
238
255
493
0.93
23
W7HD
DM42JI
205
103
308
1.99
24
KP3FT
FK68QA
80
127
207
0.63

The table shows that many of us out here on the west coast were lonely. Rich, WD4RBX has always been one of the best performers. It is not that the West Coast states have bad propagation; there was not much population of PropNET participants west of the Mississippi River.  We really need to improve this next year. I consistently had good 6-Meter propagation to the Central and Southern Plains, as well as the northern Rockies and Northwest. We just had very little and late participation out here on PropNET.
I concentrated on pointing at the PropNET population, and it resulted in me having an average PropNET capture length short of 1,900 kilometers almost 300 more than anyone else on the continent. 

                                          
Conclusion:
It really was a great year, the best since 2011. There were some bad days and at times elevated solar activity. I would expect another great year next season as solar activity continues to decrease. The recent (September 2017) surge in solar and geomagnetic activity was expected and should be short term. Do not think this recent surge has any real meaning. You might think of this as Cycle 24’s last gasp.

Es are back. I hope you got a chance to play. Thank you East Coast and you out here in the west need to put out a signal next year.

Active Days
The following days for this Spring/Summer Es Season had over 2,000 10M PropNET and Non-PropNET captures for the UTC day.

Note the concentration of signals east of the Mississippi River.
This was very common through the season. I thought this was a bit late in the season for a very active day. 

This was the most active of the entire season and I didn’t get to participate that day.

Another day in which the eastern half of the continent had most of the fun.

One of the better days out west.   Ou captures require more distance and double-hop. 

Later season activity.

Another light day out west.

Generally there is an outstanding day around this date. It was one of my most productive days.

Final Thoughts
Spring/Summer Sporadic Es are back.  Had we had a few more stations west of the Mississippi, no telling how active it would have been.

My philosophy and experience is Es beget Es. They show up on 10-Meters for a number of minutes, they appear on 6-Meters. Once strong and intensive on 6, there are good chances on 2-Meters.

I expect a few good years are ahead of us. Don’t miss it!
Please join us next year. A good time should be had. Expect more Trans-Atlantic and Trans-Pacific.
I enjoy doing this, but only if more of you participate. Lurking is participating too.

 Thanks again for reading and I hope it added to your understanding that this band (10-Meters) isn’t dead when the solar cycle drops.

73 Art Jackson KA5DWI/7 Arizona