More on the Minima transceiver

My mention of this Ashaar Farhen design yesterday seems to have been very popular, so I have dug out a bit more information. As it stands it produces 1W pep but it is easy to add a further PA.

See http://www.sarfata.org/ham/minima/ .

Although a kit of parts is available, I am not aware of a full kit with enclosure and a PCB being available as is the case with the BitX from Hendricks Kits.

Daytime 472kHz WSPR 5mW ERP and earth-electrode "antenna"

Nothing exceptional overnight.

This morning, I see I am being spotted by G4JVF (151km), M0ELS (81km) and G8HUH (250km).   I am spotting PA0O (440km) and PA3ABK/2 (306km). All not bad for full daylight propagation.

Sunspots up today

Sunspot number is climbing again and stands at 78 today (was 49 yesterday). 10m propagation is again expected to be "fair".  So far just local G4IKZ (18km) and LZ1OI (2153km) copying my 500mW 10m WSPR beacon but it is still very early.

The Minima transceiver

See http://www.phonestack.com/farhan/minima.html

This is the latest project from Ashaar Farhan. Component cost is said to be less than $100. This is based around a Si570 sythesiser and a programmed Arduino micro-controller IC. It looks a simple to duplicate rig covering up to 30MHz. It is the successor to the BITX rig I think. The IF is 20MHz. If you only want 0-15MHz or 15-30MHz (i.e. not both) the rig get even simpler.

Crystal alternative?

Buying crystals for specific frequencies is now getting very expensive. There may be a newer alternative.

See https://aa7ee.wordpress.com/2015/01/12/a-crowdfunded-si5351-breakout-board-from-jason-nt7s/ .

This synthesised solution allows any frequency from 8kHz to 160MHz to be generated.

Solar activity

See http://www.solen.info/solar/.

It is easy to overlook the peaks and troughs of solar activity when looking at averages. When solar activity has brief peaks, conditions can often be way above average. Some have even caught brief 6m F2 openings by remaining alert.

That is why 10m is such a fascinating band . Even in years with almost zero or no sunspots I have worked South Americans with QRP SSB with simple wire antennas. Never give up just because the average sunspot number is low.

10m USA today?

It is now 1240z and there are no spots of my 500mW 10m beacon from the USA yet.  I see that the band is open between the USA and Germany so maybe I am being impatient. However, with much lower sunspot numbers it is possible I'll not be heard in  the USA on 10m today at all with my low power beacon.

UPDATE 1330z:   I spoke too soon!  WA2PJI (5550km) spotted me first at 1242z and there have been others since.

UPDATE 1752z:   At the moment KC1AWS (5308km) is the last USA station to have spotted my 500mW WSPR beacon on 10m at 1750z. This could change. 

UPDATE 1835z:   KC1AWS does appear to be the last USA station to spot me at 1750z. Since then, just local G4IKZ (18km).

Sunspot number and 10m

At just 49, the sunspot number is lower than for some time.   10m propagation is only expected to be "fair".

Last 10m USA WSPR spot today

QTH next to the windmill (LHS)

KB1VXY (5308km) was the last to spot my 10m 500mW WSPR-AXE-CW beacon today at 1802z. Since then, just local G4IKZ (18km) spotting me. Time to go QRT on 10m but I'll remain on 630m WSPR now and through the night. I have just resync'd the PC to internet time.

My 10m antenna is not the world's best.  At some point, when fitter, I hope to re-erect  a single band antenna for 10m use, possibly my Homebase-10 design on my main website.

472kHz - WSPR spots on TX (5mW ERP) in last 2 weeks

Using the short baseline earth-electrode "antenna" on 472kHz WSPR in the last 2 weeks I see my best DX on 5mW ERP was F1JBB (722km) in IN95 square. I still need to count the unique stations, squares and countries with 5mW ERP from this QTH.

472kHz TX results (5mW ERP WSPR) on earth-electrode "antenna" in last 2 weeks