Ham Hum March 2016
The official newsletter of The Hamilton Amateur Radio Club (Inc.) Branch 12 of NZART - ZL1UX Active in Hamilton since 1923
Hamilton Amateur Radio Club Inc. Serving the Hamilton Community for over 90 Years
ZL1UX
Next Meeting 16th March Disclaimer: The Hamilton Amateur Radio Club (Inc) accepts no responsibility for opinions expressed in this publication. Where possible, the articles source details will be published. Copyright remains with the author or HARC. All rights reserved.
Contact Details Patron: Russell Richardson ZL1RWR President: “Jono” Jonassen ZL1UPJ zl1ux@nzart.org.nz Vice Presidents: Gary Lodge ZL1GA Gavin Petrie ZL1GWP 843 0326 zl1gwp@nzart.org.nz Secretary: Phil King ZL1PK 847 1320 zl1pk@nzart.org.nz AREC Section Leader: “Jono” Jonassen ZL1UPJ zl1upj@nzart.org.nz Deputy Section Leader: Phil King ZL1PK 847 1320 zl1pk@nzart.org.nz Treasurer: Tom Powell ZL1TJA zl1tja@nzart.org.nz Committee: Brett Pascoe ZL1FPG Mike Sanders ZL2MGS 855 1612 zl2mgs@nzart.org.nz Robin Holdsworth ZL1IC 855 4786 Sam Birch ZL1OBI Terry O’Loan ZL1TNO Ham Hum Editor: David King ZL1DGK 579 9930 zl1dgk@nzart.org.nz Ham Hum Printer: John Nicholson ZL1AUB 855 5435 ATV Co-ordinators: Phil King ZL1PK 847 1320 zl1pk@nzart.org.nz Robin Holdsworth ZL1IC 855 4786 Market Day Co-ordinator: harcmday@nzart.org.nz Robin Holdsworth ZL1IC 855 4786 Webmaster: Gavin Petrie ZL1GWP 843 0326 zl1gwp@nzart.org.nz Club Custodian: Currently vacant QSL Manager: Gary Lodge ZL1GA Net Controllers: 80m net—Phil King ZL1PK 847 1320 zl1pk@nzart.org.nz 2m net—Phil King ZL1PK 847 1320 zl1pk@nzart.org.nz NZART Examiners: ZL1IC, ZL1PK & ZL1TJA
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From the Editor Not much to say this month. I’ve been busy with yet another move, this time to Te Aroha and closer to Hamilton. I even missed the Te Puke club junk sale, again. I saw some pictures of Jock White activity from around ZL-land, and it looked like many people were having lots of fun. I hope you all had fun.
Next Committee Meetings 2 September and 7th October nd
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The K7RA Solar Update Average daily sunspot numbers over our reporting week (February 25 through March 2) were marginally higher than the previous seven days, going from 37.9 to 41.4, while average daily solar flux was down by just one point, to 92.9. Average planetary A index changed from 10.1 to 5.9 and average mid-latitude A index went from 12.6 to 5.3., so it was a quiet week with stable geomagnetic conditions. Predicted solar flux from USAF/NOAA for the near term is 100 on March 4-7, 105 on March 8-13, 100 on March 14-15, 95 on March 16-20 and then bottoming out at 90 on March 21-26. Flux values then peak at 115 on March 30-31. The planetary A index prediction shows 12, 15, 20, 15 and 10 on March 4-8, then 8 on March 9-11, 5 on March 12 and 12 on March 13. The predicted A index then makes a huge jump to 30 on March 14-16. This perhaps is from a recurring coronal hole, because on April 10-12 the A index again goes to 30. Note that in midFebruary there were similar numbers on February 17-19 of 38, 34 and 29. Petr Kolman, OK1MGW, of the Czech Propagation Interest Group (actually they call it the Propagation Interested Group, but I suspect Interest Group is a better translation to standard American English) sent his outlook for geomagnetic conditions. He says to expect quiet to unsettled conditions on March 4, quiet to active March 5-6, quiet to unsettled March 7-8, quiet to active March 9-10, quiet to unsettled March 11-12, quiet to active March 13, active to disturbed March 14-16, quiet to active March 17, mostly quiet March 18-19, quiet on March 20-21, mostly quiet March 22-24, quiet March 25-26, quiet to unsettled March 27, quiet to active March 28-29, and quiet to unsettled March 30. Petr expects an increase in solar wind on March 5-6, 9-10, 13-16 and 27-29. Notice that his expected active to disturbed conditions on March 14-16 lines up with the prediction for an A index of 30 on those same dates from USAF/NOAA. February is done, so let’s examine our 3-month moving average of sunspot numbers. According to our own data, Cycle 24 peaked with a 3-month moving average of 146.4 and 148.2 centered on February and March of 2014. Four months later the moving average centered on July 2014 was 109.2, and December 2014 was 107.8. January 2015 was 98.2, the first time the average was below 100 since September
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2013. July 2015 was 69.1, December 2015 was 55.4, and the latest number centered on January 2016 was 53.5. (The moving average centered on January is an arithmetic average of daily sunspot numbers from December 1, 2015 through February 29, 2016. Adding all sunspot numbers for those days totals 4,868 and divided by 91 days yields an average of 53.4945 or 53.5. The last time the average was at this level was February 2011, five years ago, when it was 55.7. The ARRL International SSB DX Contest is this weekend, and it runs from 0000 UTC March 5 through 2359 UTC March 6. See http://www.arrl.org/arrl-dx for details. Eric Guzman, NP3A, had a comment on N0JK’s note about what a difference a year makes on 10 meters. Eric wrote “I think is not only 10 meters. This February I will complete one year of monthly reports using our Club Skimmer KP3Z data. “Comparing the 2015 to 2016 tally for the ARRL DX CW Contest, 80 meter activity was down 9 percent, 40 was up 9 percent, 20 meters down 20 percent, 15 meters down 75 percent and 10 meters down 89 percent. I believe this is just the number of callsigns copied, but it was 14,503 on 10 meters last year, and only 1,644 this year. “Full SH5 reports for both weekends can be found here: http://www.np3a.com/ website/index.php/skimmer-sh5 “Huge difference on 15 meters as well. Of course there are other factors that affect these numbers like participation, but in general propagation is the main factor.” Thanks Eric. Forty meters was the only band with an increased count, and with propagation down on 10, 15 and 20 meters, where else would you go? For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of the numbers used in this bulletin, see http://arrl.org/the-sun-the-earththe-ionosphere. An archive of past propagation bulletins is at http://arrl.org/ w1aw-bulletins-archive-propagation. More good information and tutorials on propagation are at http://k9la.us/. My own archives of the NOAA/USAF daily 45 day forecast for solar flux and planetary A index are in downloadable spreadsheet format at http://
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bit.ly/1VOqf9B and http://bit.ly/1DcpaC5 . Click on “Download this file� to download the archive, and ignore the security warning about file format. Pop-up blockers may suppress the download. Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation. Instructions for starting or ending email distribution of ARRL bulletins are at http:// arrl.org/bulletins. Sunspot numbers for February 25 through March 2 were 26, 41, 37, 38, 44, 39, and 65, with a mean of 41.4. 10.7 cm flux was 91.7, 89, 90.4, 93.2, 90.9, 96.8, and 98.2, with a mean of 92.9. Estimated planetary A indices were 5, 7, 4, 4, 5, 9, and 7, with a mean of 5.9. Estimated mid-latitude A indices were 6, 5, 3, 4, 4, 8, and 7, with a mean of 5.3.
20m Delta Loop This antenna is fed for vertical polarisation, to give a low angle of radiation for DX and also a nearly omni-directional radiation pattern (broadside is the best direction by about 3 dB). I have built two versions of this antenna; one using coax as a monoband antenna for 20m as simulated below, and the second as presently used with 450 Ohm slotted ladder-line feeder for multiband use (20 and 15m). In the monoband application, the impedance at resonance on 14.2 MHz of about 100 Ohms is transformed by a quarter wavelength of 75 Ohm cable (3.5m long) to give a good match ( better than 2 : 1) across the whole band. The 75 Ohm coax braid is connected to the lower side of the loop element. I don't use a balun as the antenna is not balanced, due to the offset side feedpoint, but do implement a coaxial choke at the 50 Ohm cable connection to the matching stub of 10 turns, 20cm diameter. The antenna is 7.71m per side, with the feed point 3/4 of the way down one side (5.78 m from the top) note; 3/4 * 1/3 wavelength = 1/4 wave, this is important to obtain vertical polarisation. This antenna is also effective on 15m provided open wire feeder is used up to the antenna instead of coax. I have found 10m DX performance to be rubbish! Simulation confirms this.The pattern is rather directional on both the higher bands.
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Drawing of antenna
The NEC4WIN95 design file; CM Equilateral Delta loop for 20 meters, apex up. CM Feed point 0.25 lambda from top corner for vertical polarisation CM 2:1 75 ohm coax quarter wave-length match assumed. CM G4EZT Tree supported antenna. CE GND Reference UNITS Meters Height 8.000 Over Ground 13 5 (Diel. - Cond. ÂľSiemens) Boundary Circular F 14.200 GW 0 8 0.000 -3.854 0.000 0.000 0.000 6.675 0.002 GW 1 20 0.000 0.000 6.675 0.000 3.854 0.000 0.002 GW 2 8 0.000 3.854 0.000 0.000 -3.854 0.000 0.002 S 1 23 100 0 Coax 100
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The SWR plot
The Zenith plot
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The Azimuth plot.
- G4EZT
Five by Nine... QRP... How can it be? What does an S-Unit really mean and how can a QRP station sound like a 500w station? I rarely go up to the phone portion of the bands. Since I started doing QRP and CW last summer I think I've only made two SSB contacts just because my focus has been CW. But last night I was working on a bench project and tuned the Elecraft KX3 up to the phone portion of 40m for some entertainment.
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A station in Rhode Island was testing his amp with a new antenna and was getting reports from various stateside operators. There was a lull where no one was answering his CQ so I thought I'd give him a call. He was peaking at S9 on my KX3's meter and he also sent me a signal report of S9 with some 10 over peaks. I then told him I was a QRP station running 10 watts and heard the usual surprised reaction from a QRO station. I gave him reports as he switched back and forth from running barefoot ~75w to his amp ~500w. With his amp on he was an S9, running barefoot he was S8. So the amp gave him one additional S unit. In terms of hearing him I would have been hard pressed to tell much difference simply by volume. He was perfectly copyable without noise with the amp off. We also did some tests with my station at reduced power (as if...) At 10w-12w output I received a S9 to S9+10. Reducing output to 5 watts netted me a S8 report and when I reduced to 1 watt (one watt) he was still able to comfortably copy me and I received an S5. So with my station at 1 watt and his running 500 watts we could still converse via SSB. Ladies and Gentlemen you don't need as much output wattage as you think you do. He was running through a newly constructed homebrewed vertical while I was using my 80m OCF Dipole. We didn't discuss what sort of radial system he had installed, but the difference in antennas was likely was the deciding difference in our stations. We were about 500 miles apart and his vertical probably had more lowtakeoff gain than my dipole, or possibly more ground loss so I probably had better high angle gain on him for the short 500 mile skip. I think the take-away from this exercise is that the antenna is generally the key rather than transmitter power. If I can get 6 dB of gain from my antenna I have in essence quadrupled my effective radiated power. Quadrupled? Yes, Quadrupled effective output power. Power and S-Units You've probably heard it before but it's worth a refresher... Our radio's meter display a measurement in "S-Unit". To move the meter up one S-Unit the receiver must hear 6 more dB (decibels). So one S-Unit is 6 dB. A decibel is :A Power Ratio: dB = 10 Log P2/P1 A Voltage Ration: dB = 20 Log V2/V1 You increase 3dB each time you DOUBLE your power
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That's worth repeating... You increase 3dB each time you DOUBLE your power. So to gain one S-Unit you must quadruple your power. So if you are running 100 watts, to gain one S-Unit using the same antenna system you must increase your power to 400 watts. If you are running QRP SSB (10 watts) that is only 1.5 S-Units down from 100 watts. 100w / 2 (-3dB) = 50w / 2 (another 3dB or 1 S-Unit) = 25w... etc. Antennas offer the cheapest increase in dB Note the statement above "using the same antenna system". That's the key then isn't it? It's easier to get 6 dB of gain from an antenna than from wattage. A 40m doublet can offer significant directional gain especially when operated on higher bands. Now unless it's rotatable you will be at the mercy of the directionality of its lobes but if you have trees or tall structures you can very cheaply string up a few dipoles oriented in different directions and for far less money that a 500 watt amp (6 dB). If you can only have one wire antenna you may miss out on some DX in the antenna's nulls but you will have some stellar gain in the direction of the lobes. Of course rotatable yagis and beams are the best but now we are talking about real money again. I'm talking bang for the penny. You don't have to buy a wire antenna. Some Dacron rope or weed-eater line and some surplus insulated wire is all you need. You can even make your own feedline cheaply from electric fence wire and insulators. We have a great hobby, but there are so many aspects of it that sound like common sense when they really are not... like increase your power. Increasing power gains you very little compared to a better antenna systems. Put that in your 811A amplifier tube and smoke it ! That's all for now. So lower your power and raise your expectations (or your antennas) 72/73 Richard, N4PBQ
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Upcoming Happenings & Events Date
Happenings & Events
1st March
VHF Net, 146.525 MHz, 20:00
4th March
NZART HQ Infoline
5th March
Te Puke Junk Sale (Paengaroa)
7th March
HF Net, 3.575 MHz, 19:30
8th March
VHF Net, 146.525 MHz, 20:00
14th March
HF Net, 3.575 MHz, 19:30
15th March
VHF Net, 146.525 MHz, 20:00
16th March
Monthly Club General Meeting
18th March
NZART HQ Infoline
21st March
HF Net, 3.575 MHz, 19:30
22nd March
VHF Net, 146.525 MHz, 20:00
27th March
NZART Official Broadcast
28th March
HF Net, 3.575 MHz, 19:30
29th March
VHF Net, 146.525 MHz, 20:00
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1st April—NZART HQ Infoline 2-3 April—NZART Low Band Contest 15th April—NZART HQ Infoline 20th April—Monthly Club Meeting 24th April—NZART Official Broadcast 6th May—NZART HQ Infoline 20th May—NZART HQ Infoline 21-22 May—NZART Sangster Shield Contest 29th May—NZART Official Broadcast 4-5 June—NZART AGM/Conference 11-12 June—NZART Hibernation Contest 2-3 July—NZART Memorial Contest 16th July—WIA VK/ZL Trans-Tasman Low-Band Contest 6-7 August—NZART Brass Monkey Contest 13th August—Annual Hamilton Market Day 1-2 October—NZART Microwave Contest 5th November—NZART Straight Key Night 3-4 December—NZART Field Day Contest
For more information on any of the above please contact myself or any committee member.
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Club Information Contacts :Business Meeting:
1930 First Wednesday of each month except January 88 Seddon Road, Hamilton
General Meeting:
1930 Third Wednesday of each month (except Jan) 88 Seddon Road, Hamilton
Homepage: eMail:
http://www.zl1ux.org.nz branch.12@nzart.org.nz
HF Net: VHF Net:
3.575MHz LSB 1930 Mondays 146.525MHz simplex 2000 Tuesdays
2m Repeater: STSP Repeaters: ATV Repeater:
145.325MHz -600kHz split 146.675MHz -600kHz split 438.725MHz -5 MHz split Off air pending channel changes
Cover Photo: http://thesurvivalmom.com/ ham-radio-not-just-science-nerds/
Sender
Hamilton Amateur Radio Club (Inc) PO Box 606 Hamilton 3240