Early "through ground" communications experimenter

http://earlyradiohistory.us/1902stu.htm has some details of Nathan Stubblefield's early (late 19th/early 20th century) experiments with conduction (earth mode) telephony communications through the ground.

Sometime soon I want to try some more experiments with this mode using QRSS or PSK31 at frequencies below 10kHz.

1 FET transceiver built

Today I built a single FET transceiver for 80m using just a handful of components (see pictures)

Currently it puts out 10mW on 3.579MHz (will be changed to 3.560MHz when I get another xtal) and uses the same single MPF102 FET in a tunable regen RX covering 3.50-3.62MHz. On RX it is picking up plenty of CW stations on the FISTS net so must be reasonably sensitive. The first QSO should be tomorrow on a sked with a local station a few miles away. If you want to try to work me using this rig please let me know via email at rogerlapthorn(at)gmail.com.

VLF/LF converter

The VLF up-converter on my website (used to receive SAQ last year) has a new box and had a tidy-up! It works well and is sensitive from around 2kHz up to 200kHz. It should be useful on 137kHz receive. The actual circuit is built ugly style on a small piece of copper clad PCB material and this is about half the size of the 9V battery used to power the converter. The circuit uses a "back to front" SBL1 mixer with a 2N3904 oscillator and post mixer buffer.

The original lash-up received SAQ at RS58 and a QSL card was received for this historic 17.2kHz CW transmission from Grimeton in Sweden.

The various time signals (on 50, 60, 75 and 77.5kHz) are audible as are the Russian Alpha beacons below 15kHz. There are various unidentified data transmissions from 17kHz to around 80kHz audible but not identified.

New UHF/SHF super-DX mode?

The ARRL Propagation report (link on my website) today reports some interesting findings about very high altitude noctilucent clouds reflecting radar signals, raising the possibility that extreme, INTERCONTINENTAL, UHF/SHF DX might be possible using reflections from such clouds. See
http://www.sciencedaily.com/releases/2008/09/080925144806.htm

"...the clouds contain ice coated with sodium and iron from micro-meteors and sit at about 53 miles (85 km) altitude, mostly between 50-70 degrees latitude, and sometimes as far south (or north, in the southern hemisphere) as 40 degrees latitude or less.

The clouds are highly reflective of radar signals, and instead of diffraction as we see in ionospheric propagation, ripples in the clouds seem to reflect in unison, reinforcing each other.

Noctilucent clouds are sometimes visible at night, because their altitude is so high that they reflect sunlight into areas of darkness. They are also known as polar mesospheric clouds, and appear most often at twilight during the summer."

Imagine working many thousands of miles on 10GHz QRP by a mesospheric
reflection mode. Now that would be something REALLY different!

GI4DPE on 501kHz

501kHz was in a reasonable state a couple of evenings back with Finbar GI4DPE being a steady signal down here on CW in East Anglia. I must get some QRSS software as there have been a few stations on which I have not been able to decode. QRSS "by ear" is not easy!

HF AM excursion - all 9 bands!

M0BXT and I usually have a natter on 144.55MHz vertical AM on Mondays at 8pm. We were on last night but got distracted doing some tests on all 9 HF bands using QRP AM.....

Starting on 10m and working down to 160m we very briefly exchanged reports at 4W and then with some 10-20dB less to see how signals compared across each band on our end-fed antennas tuned via an auto-ATU at each end.

I have to confess to a brief AM QSO on 30m (shame, disgrace!!) but only for 20 seconds at most so no harm was done to the planet.

We managed solid QSOs at over S9 over our 2 mile path on all bands apart from 24MHz where signals were weaker, maybe because our wires had deep holes in radiation on this band. The best band was 80m where signals were 59 + 50dB or so. 160m was also pretty good.

M0BXT and I hope to have our first two-way single valve or single transistor transceiver QSO in the next few weeks on 80m but this will be CW.

Decent DX around despite the sunspots

This last week has seen some decent DX around despite the zero sunspot number. V51YJ is booming in on 20m CW this evening. VK3PA was audible on 80m SSB a few nights back at sunset and YB6INU a decent copy on 40m SSB.

On 501kHz (600m) the SM6BHZ and DI2AM beacons have been reasonable signals in the evening this week.

40m in good shape

Listening on 40m tonight in the contest there was plenty of decent DX around on SSB including PJ4NX, ZW5B, K5ZD (who "QRZ? ed" me with 10w and short endfed), W1UE and others at decent strength.

Icom IC7000S

Anyone know if this version of the IC7000 series (10W low power I think) is available in the UK? This would make a nice QRP radio for many.

Interesting solar fact

August 2008 was the first calendar month with no sunspots since 1913 according to the ARRL propagation report this evening. They also note that cycle 19 (the biggest on record) was preceded by long periods without spots. You never know, cycle 24 might turn out to be a whopper and we'll all work the world on 70MHz with milliwatts.