AmateurRadio.com

Nice drawing of Morse key by Dutch radio amateur Dick Kraayveld, PA3ALM (http://www.morsecode.nl/pa3alm.html)

In the early 90’s there were some interesting studies performed on Morse code recognition and the effects of pitch frequency, signal to noise ratio and code speed. They were part of the PhD work of Peter Montnémery who is a medical doctor and also radio amateur SM7CMY. I reread these papers now since there was a discussion on the pitch frequency (CW pitch resolution) just recently on the Elecraft mailing list. This discussion comes up from time to time, as it did for instance in 2006 also (Sidetone questions — copy speed vs sidetone pitch).

The two first papers are probably the most interesting ones for radio amateurs, so therefore I have posted their abstracts and a key figure from each of them also.

Press figure for larger size

Paper 1: Montnemery, P., Almqvist, B., & Harris, S. (1991). Recognition of Telegraphy Disturbed by Noise at Different S/N-Ratios and Different Telegraphy Speeds A Comparison to Short-Tone Audiometry. Scandinavian Audiology, 20(1), 33-39.

Abstract: “The ability to recognize telegraphy at different S/N ratios and telegraphy speeds was compared for 10 normal-hearing men trained in detecting telegraphy. The ability to recognize telegraphy disturbed by noise decreased with increasing telegraphy speed and reduced S/N ratio. The recognition of telegraphy disturbed by noise seems to follow the relations known from experiments with short-tone audiometry.”

The figure above (Fig. 5) shows recognition in % vs signal to noise ratio (SNR) for speeds 13, 25, 40, 63, 82, and 103 characters per minute (CPM) which when divided by five correspond to 2.6, 5, 8, 12.6, 16.4, and 20.6 words per minute (WPM). Note how recognition at the 90 % rate is easiest (works under lowest SNR) at 5 WPM, then 8, then the exception for the slow speed 2.6 WPM, and then gets even harder at speeds 12.6, 16.4, and 20.6 WPM.

The first paper shows how lowering the speed enhances recognition when conditions are poor. Unfortunately only 250 and 500 Hz were tested in the second paper, but it should be clear that a low tone is preferable. If one were to do a follow up study, it would be interesting to zoom in on the frequencies between 250 and 500 Hz for further testing. Since 40 and 80 CPM is only 8 and 16 WPM, it would also be interesting to test at higher speeds.

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].

SWR 1.1:1, power 5 watts and memory CQ message

With getting most if not all of my "to do list" done it was time once again to swing the Alexloop into action and have a nice late afternoon of ham radio and relaxation. Setting up the loop has become faster for me I'm getting the hang of the in's and outs of the loop. I also am able to tune the loop in less than 20 seconds and be up and running on different band segments. The SWR is anywhere from flat to 1.7:1 and the band width is very good and retuning is not needed unless 20 khz changes are needed. This weekend the Worked all Germany CW contest was going on so I wanted to be a point giver for the contest. With 5 watts, my KX3 and the Alexloop in the living room I was able to contact the following  all on 20m:

DK1NO
DK9PY
DR4A
LX/DF1LON

  I did try dropping the power lower than 5 watts but is was just not doing the trick. I then was on 30m and WA3SCM Dave was calling CQ. I came back to him using 5

Time to recharge the battery

watts. I was at times in and out with Dave but he was in P.A and that's off the backside of my loop antenna. Dave was running a long wire with 100 watts and all was going well until my KX3's batteries decided to die! The KX3 just shut down and my lesson was learned in that I should be monitoring the voltage on the KX3 (via it's display) and I would had known it was due time to change over to my external battery supply. I did go upstairs and get the extra battery but it was too late as Dave was gone. I did email him and explained what happened and on Sunday he emailed me back. He was wondering where I had gotten to and did tell me that he was very interested in the Alexloop as he has worked with lots of different types of loop antennas.
I was able to spend some time on the radio today (Sunday) and I again tried 10m to see what was happening.....it turned out that 10m was good to me today. I was only able to make 2 contacts but they were sweet ones!

IS0GQX from Sardinia
MD0CCE from Isle of Man

I was shocked at both these contacts two very nice and sometimes rare areas and I did both in one day! If I get the time this evening I will try some more radio time but if I don't get around to it I am very happy with the two contacts I did make today.   
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

It was another great day on 10 meters. I was spotted on 5 continents with 5 watts WSPR. No time for doing other things on the radio such as making real qso's. But this was fun too.

Paul Stam, PC4T, is a regular contributor to AmateurRadio.com and writes from the Netherlands. Contact him at [email protected].

Series Six Episode Twenty-One of the ICQ Amateur / Ham Radio Podcast has  been released. The latest news, Chris Howard, 2E0CTH discusses distance learning courses to pass the UK Advanced Amateur / Ham Radio licence with Steve Hartley (G0FUW) and Frank Howell, K4FMH reports from North America.

• Radios in decline among young
• UK ham radio licenses hit new high
• Australian D-STAR on 40 metres
• Radio hams honored for community preparedness
• Tuning out: Analogue radio to disappear by 2018
• Ofcom propose legalising 27 MHz SSB
• GB0HE
• GB2SDD on air for JOTA
• W7OO Contribution Challenge

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

Hanz, W1JSB and I hiked near Profile Falls in Bristol today. We worked Germany, Canary Islands, the Netherlands, Ontario and North Carolina.

Here’s a photo of Hanz setting up his gear on the bridge abutment.

We set up our gear on the old rail right of way on the edge of Profile Brook. The rails are gone and the bridge is unused, but the stone abutment remains. It’s a pretty spot. We operated here in the early spring.

I heaved a line into a tall maple tree near the old bridge site. We pulled up a 33 foot wire and I connected a 9:1 unun and started operating the KX3 on 15 meters. The Worked All Germany contest was in full swing, so we worked quite a few German stations. Here’s my log:

19 Oct-13 1900 21.008 CK3AT CW 599 599 Ontario
19 Oct-13 1901 21.009 DK9OY CW 599 599 Germany
19 Oct-13 1903 21.016 DL0LK CW 599 599 Germany
19 Oct-13 1920 21.020 DK0SU CW 599 599 Germany
19 Oct-13 1924 18.085 KS4S CW 599 599 NC
19 Oct-13 1928 18.092 EA8BBJ CW 559 599 Canary Isl

After operating on 15 meters for a while, Hanz took over. He operated his souped up 20 meter SWL rig in the yellow Pelican box. He worked several Germans.

After a while we switched to 17 meters with my KX3. Hanz worked KS4S in North Carolina and PA3DZM in the Netherlands, and I worked EA8BBJ in the Canary Islands.

The afternoon sky had clouded over and most of the leaves were off the trees. But the air still had a rich fragrance of fall and the lingering warmth of Indian summer. We hadn’t operated together for nearly a month, and it was
great to get out with our QRP gear again.

Jim Cluett, W1PID, is a regular contributor to AmateurRadio.com and writes from New Hampshire, USA. Contact him at [email protected].

The old timers reading this are going to be laughing I think!

Ten metres was in good shape today and I’d just finished some programming work on the Anytone rig in the car. I tuned up around 29MHz to see if there was any AM coming through. Sure enough there was.

Barry N1EU was coming through nicely, running an Apache labs SDR which was sounding great. Barry was kind enough to pull my 10W/whip signal out and give me an S5.

Really thrilled to have made my second AM QSO! Hopefully there are more to come.

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

Things around the house are slowly getting packed away but the ham radio bug still bites. It's true what they say....."you don't know how much you miss something until it's gone.....or semi packed away" Ham radio is not gone from VE3WDM, the antenna may be sold and gone, coax all rolled up and boxed. The Elecraft K3 sits idle at the desk but all is not lost as the KX3 and Alexloop are calling my name!! On Saturday once our Thanksgiving preparations  were going smooth...the turkey was in the oven and the side dishes were slowly cooking it was time to feast on some missed ham radio time. The night before, I charged the batteries in the KX3 having them ready to go if the opportunity came about. It did on Saturday afternoon so I setup the Alexloop in the living room and fired up the KX3. It sure was nice to hear some atmospheric noise and even the woodpecker QRN from some offending appliance was ok as well. (the KX3's NB and NR took care of any offending interference)
I had been reading about some hot openings on 10m's from some of my blog buddies but I found 10m to be dead. I ended up hanging around 20m at the QRP watering hole. My power was reduced from it's normal 5 watts to 3 watts. Julie was on her Mac beside me and since our living room TV had been sold it was a Sony boom box radio entertaining her with tunes. The Sony radio along with it's antenna was only 10 feet from the Alexloop anymore power than 3 watts could be heard over the radio. The way Julie see's it CW is NOT music to the ears and it's much better to be on the radio and have Julie happy thus down went the power.
As for contacts I only made 2 short contacts as I did not have much time and was up and down checking on dinner. I was able to make it into Utah to WA7LNW and N3PDT in Missouri, not much but from the ground floor, indoor antenna and 3 watts I was happy with the contacts. I kept tabs on my signal using the Reverse Beacon Network and it showed only U.S stations were copying my signal. I was on again Monday evening and could hear PV8ADI from Brazil at S8 but I was not able to make contact with him.
The KX3 now is resting on the radio desk and the Alexloop is away in it's carry case until next time. I was please to get this short radio time in and the results were pretty good as well.
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].