The wind down of Solar Cycle 24

solar-cycle-sunspot-numberThe current Solar Cycle has proved to be a bit disappointing for amateur operators and will descend to a minimum within the next 2 to 4 years.   We are already seeing dead bands in most daily forecasts.  But how does our current cycle compare to earlier cycles?

The following diagram shows peak sunspots from all observed solar cycles since the 1600’s when sunspots were first recorded by astronomers.

It turns out that cycle 24 is not particularly unusual in the scheme of things!

grandcyclesswsc120009-fig4

And for an even longer perspective …

The last 10,000 years of sunspots!
The last 12,000 years of sunspots!

So what will happen in the next cycle (cycle 25)?

You will find a number of predictions online.    Because of the peak sunspot number in our current cycle there seems to be a growing consensus that we are unlikely to see the really nasty outcome of a second “Maunder minimum” (a period of almost 70 years with virtually no sunspots at all).   It is likely, however, that we are exiting from the “Grand Maximum” period.   We may well be entering a regular period that will look a bit like the period from 1724 to 1924 (a whole two centuries in duration!) in which sunspots are OK, but not good enough to make the record books.   The result is that we can expect the next cycle to be somewhat similar to Cycle 24.

Sorry to bring you the bad news!   Let’s hope one of those mid  to late 20th Century sunspot highs comes again in our lifetimes!

WARC Inc AGM – 15 March

Our Annual General Meeting was a speedy one, meaning plenty of time for tea and coffee and a chat afterwards.  The AGM was held on Tuesday 15 March 2016 at the Lutheran Church Hall, King St, Mt Cook, Wellington at 7.30pm.   Officers and committee members from 2015 were re-elected unopposed.

You will find posted below our final annual reports, financial accounts and draft minutes of meeting (to be confirmed at next year’s AGM).

Quartz Hill Developments

The QHUG remote site enclosure being fitted out
The QHUG remote site enclosure being fitted out

Doug ZL2AOV writes in his report on the WARC February 2016 club meeting:

“QHUG members are expecting “a very active year” – Bernard ZL2BD made a Powerpoint presentation showing his summer work fitting out the fibreglass box with solid-state linears and power supplies, switching regulators to provide 230v DC, 24v and 12v DC for the various items, plus a solar panel regulator and wiring harnesses for the huge battery bank. Progressive testing is imminent – any noise problems will be dealt with as they arise. Other jobs to do are: complete the antenna switching and the SCADA software to operate remotely (SCADA = Supervisory Controller & Data Acquisition). Frank ZL2TTS has been working on this. Cooling circuitry also needs assembly and installation; the enclosure’s front panel will be modified for this. Noted that Ralph ZL2AOH is stepping down as QHUG treasurer after many years.”

WSPR

WSPR shows open paths on the HF bands

At our 16 February meeting, James ZL2ET gave us an interesting talk on WSPR (pronounced “whisper”) and its applications.

Doug ZL2AOV summarised it as:

“James ZL2ET discussed the challenges and possibilities involved in low-power, very low-speed propagation testing. WSPR (Weak Signal Propagation Reporter) is a computer-driven way to find out which bands are open, when and between what sites; it correlates this data and provides it on-screen.

“Using a presentation prepared by Steve Nichols G0KYA, James took us through the equipment needed: a computer with a sound-card to generate the slow-speed FSK used, a transceiver with accurate and stable frequency control, a source of accurate time (propagation paths are found by comparing accurate time slots of data), and an internet link to upload the data to a central repository for automatic analysis and dissemination. Viewers can see what’s going on by pointing their web browsers at www.wsprnet.org. The files can be analysed by band, time, and even by transmitter source … allowing insights into amateur radio DX prospects.

“Transmitters don’t want to be high-powered (maximum five watts is fine) and milliwatts is possible. A Raspberry Pi model B can be programmed to provide FSK on a preferred frequency at about 10 milliwatts out; an amp can push that to 100milliwatts and a tiny bandpass filter does the rest. Timing accuracy can be guaranteed using a wi-fi usb stick to synch to external clocks.

“The protocol provides for transmission of callsign, locator square, power output (in dBm) for 100 seconds, then listening for 120 seconds. Transmission is FSK, just six Hertz.

“The designer of it all? Professor Joe Taylor K1JT, well known for other innovations in digital modes. The system’s sensitivity is stated to be between 11dB and 15dB better than the human ear. That’s way better than using PSK31 and searching for the characteristic double-lines in the waterfall display!!!!”