Friday, October 24, 2014

MFJ-2289 Big Ear Balun Evaluation

I heard someone say (read on eHam) that the balun inside the V-Block of the MFJ-2289 Big Ear was trash and they replaced it with a "better" balun.

Hmm. That's curious because I had inspected the 1:1 Guanella current balun when my Big Ear first arrived because I just had to take it apart and see what was inside, and didn't see anything alarming about the design or implementation.

So I decided to do what any curious person would do, test it and verify the loss myself.

I took another 1:1 Guanella current balun that I built and attached the two back to back after unsoldering the wires from the 3/8 x 24 studs inside the box.

I calibrated my test bed by attaching the output of the Kenwood TS-2000X set to 10-Watts with the test cables attached directly to the Elecraft DL1 dummy load and the test point attached to my Fluke 89 IV, I established a reference level of 9.911 Watts in the "thru" path.

Pthru(W) = (15.591 + 0.15)^2 / 25 = 9.911 Watts, through calibration path 
Pdut(W) = (15.163 + 0.15)^2 / 25 = 9.3795 Watts, through DUTs

P(loss) = 10 x LOG (9.3795 / 9.911) = -0.24 dB total for two baluns

Assuming equal power split, where P(loss) / 2 is the loss of just one balun, the measured MFJ-2289 balun loss is -0.12 dB.

Pretty textbook if you ask me. I'd be hard pressed to build a better one.

- Myron WVØH

Sunday, October 19, 2014

Magic Propagation Map

I have a love hate relationship with this map. It leads the average ham into believing that your 10m signal just magically "jumps" over to Europe when nothing could be further from the truth. The thing to keep in mind here is that big old mirror called the Atlantic Ocean is what supports this propagation mode from the eastern US. That first hop landing zone on the ocean is what makes all this possible.

We high plains hams have to endure the landlocked, first-skip-zone-landing-on-dirt propagation of pretty much HF band to get to DX except VE and XE. And it's no secret from any long time DXer, geography matters.

It would be neat to see a map of the actual path that the signal took hopping along its way to grandpa's house. It would reveal that the first hop would put us directly on dirt! In pretty much any direction on pretty much any band from the geographical Midwest, (Kansas, Nebraska). And yes, there are the ducts that occur and showing those patterns and paths would be super cool as well.

Oh, and I love it because it shows when the band is open.

Saturday, October 4, 2014

Last Few Outdoor Ops Stats

I've mined the RBN data to see what my SNR reports averaged for the last 3 field contests, the Colorado QSO Party, New England QRP Afield, and the North Georgia QRP Peanut Sprint all in 2014. 

Along with an average signal to noise ratio I've calculated the standard deviation as well. The std dev could be a result from shifting band conditions. I logged QSOs in two separate locations during the CO QSO Party, in an operating site in the mid-morning hours on 20m with my 40m Park Portable Doublet favoring a N/S path and the mid-afternoon ops favoring an E/W path. In any case, it is interesting to see how the antenna and propagation plays.

The NE QRP AF was operated from 1939-2145Z on Sept. 21,2014 at 1-Watt and The North Georgia Peanut Sprint was operated for the full two hour period from 2000-2200Z on Sept 28, 2014 with 1-Watt as well. The spots were gathered in the Colorado QSO Party on August 30, 2014 from 1635-1730Z at the county line between Jefferson/Boulder county line and 2015-2120Z at Weld county.

CO QSO Party

44 spots at 5-Watts
Avg SNR = 13.3dB
Std dev = 7.42dB

50 spots at 5-Watts
Avg SNR = 9.96dB
Std dev = 8.00dB

NE QRP Afield

100 spots at 1-Watt
Anthem Park, Broomfield, CO
Avg SNR = 8.51dB
Std dev = 5.91dB

NoGa Peanut Sprint

91 spots at 1-Watt
Sienna Park, Broomfield, CO
Avg SNR = 9.75dB
Std dev = 6.66dB

Tuesday, September 30, 2014

North Georgia Peanut Sprint Results

I had a fun time in the Peanut QRP Sprint. The two hour operating time is just right for a nice afternoon sprint.

I went over to the neighborhood park and setup my KX3 and Park Portable Doublet in the grass. My antenna is an open wire doublet supported by three fishing poles. The antenna at the apex is about 31 feet up and the ends are at about 23 feet. The overall length of the doublet is 67 feet. 

I ran the KX3 at 1-Watt to enter the Goober category. I logged all my contacts with N3WG's app "HamLog" on my iPad 2. The app checks dupes and allows me to export the log to a CSV file.

My power source could have been just the internal Eneloop batteries but I opted for the repurposed Dell LT 3S2P 11.1V Li-Ion pack. I use an RC battery monitor called a beeper to monitor individual cell voltages to prevent over discharging the pack. 

The 20m was the bread and butter band but did manage to eek out a few QSO's on 15m. One QSO K7JKZ was miscopied so I won't count that one in my score. All was good for the contest as the weather out here in beautiful Colorado was sunny at contest start. But around the halfway mark clouds started to roll in and by contest end the threat of rain was eminent. About an hour after the test, it started to rain. Perfect timing.

Here is my score breakdown,
1-Watt out for entire contest, Goober Class #49
Nuts = 30 (x7) = 210
Non-Nuts = 10 (x3) = 30
QSO points = 240
SPCs = 17
Total Score = 240 x 17 = 4080


Thursday, September 18, 2014

New Shakespeare Wonderpole 20 footer

Since breaking one of my Cabela's poles I decided to go with something a bit more robust. I searched the web and found South Bend offered a 20 foot pole as well as B n M in their Black Widow variety. Having already seen the Black Widow, I decided to give the Shakespeare 20 foot Wonderpole a go.

I'm glad I did. This is a 100%fiberglass, medium-fast action and is stiff enough to support an end wire easily and possibly a lightweight wire doublet when used as a center pole.

The dimensions are:
Length (collapsed with end caps): 38-13/16"
OD of Bottom section (top): 1.15"
OD of Bottom section (bottom): 1.582"
OD of Bottom section just up from screw on collar of end cap thingy: 1.29"
Weight: ~600 grams (1.31 lb)
Overall length extended is a few inches shy of 20 feet.

The 5 section Wonderpole is finished with the same tough varnish other Shakespeare products are known for and should resist scratching. The tip top is painted with a chartreuse color paint and the tip top has a wire eyelet approximately 0.012" diameter. There are two line keepers spaced about 6.5" apart on the bottom section should you find yourself in need of a place to wind your line if you needed a decent panfish pole!

Sunday, August 31, 2014

The 2014 Colorado QSO Party

I started out set up on a county line sharing Jefferson and Boulder counties.

I took the MFJ Big Ear along thinking I could more easily straddle a fence or boundary. I setup at the JEF/BOU boundary about 1500Z but at only 13 feet high, I wasn't pleased with its performance. So I bailed on the Big Ear and set up my Park Portable Doublet at 30 feet. That was better but no outing is devoid of mishap and one of my Cabela's end support poles broke near the top under stress. Battle damages or breaking something while using it aren't a concern for me. Stepping on it in my basement, that's when I would have gotten upset. I ran 27 QSOs on 20m there and decided to change location. 

I went over to a spot inside Weld county east of Erie and operated from a park. Conditions had changed a bit so I checked 15m and put out some calls on 40m. I heard some weaky squeaky signals from CO on 7.050 but was unable to QSO. I went back to 14.050 and ran 26 more before everybody left. So I tore down and headed over to Adams county. I found a spot near McKay Lake that may have worked out but it started to rain, so I came home.

That's it. 53 QSOs and now I have to figure out how to report all of this on the summary sheet! It seems overly complicated.

Here is the stats for the RBN spots.

JEF/BOU: 44 spots with an average of 13.36dB and a standard deviation of 7.42dB from 1635-1730Z with antenna radiating North/South.

WEL: 50 spots with an average of 9.96dB and a standard deviation of 8.00dB from 2015-2120Z with the antenna radiating East/West.

Sunday, August 10, 2014

2014 NJQRP Skeeter Hunt

I operated the test just east of my QTH at Country Vista Park. I walked over at about 10:30 (1630Z) and got setup and CQing by the opener at 1700Z. I started out on 20 and switched to 15 but it was deader than a door nail. I went back down to 20 and my QSO rate was 7 QSOs per hour, yikes. Oh well, I had lunch in that time as well.

My total station weight carrying over to the park was 16 pounds. That's the rig, battery, WVØH Park Portable Doublet, solar panel, Crazy Creek stadium seat, tarp, umbrella, iPad, notebook, 3 fishing pole masts, anchors and guy lines. The whole shootin' match.

So I was set up on on the air by 1655Z. Whew, five minutes to go. I spun around the dial on 15 a bit, nothing, then back down to 20 and that's where I started.

This is what my final log looked like. (In reverse order).

Thanks to all who made this a great outdoor adventure and thanks Larry, W2LJ for putting this on.