2-way QSO - "1 active device transceiver" at each end!

M0BXT's 1 valve transceiver (see left)

Last night M0BXT and I had a nice two-way QSO with a difference.

Andrew used his 1 valve 300mW transceiver (see http://tetrode.co.uk/ ) and I was using the FETer 1 FET transceiver. Reports both ways were good over the two mile path.

With the help of Andrew's RF test gear I was able to accurately measure the sensitivity of the FETer rig and its power output. Sensitivity is better than -100dBm (around 2uV) for a reasonably comfortable level in the crystal earpiece. Signals could be detected (just) at around -105dBm sensitivity. The TX has a bit more power than I was able to measure crudely - around 18mW output with a 12V supply. These figures are really quite remarkable for the few parts used.

Next aim is to work some further distances with the FETer. I am sure this will be possible.

Our grandson

Here are a couple pictures of our little grandson, taken in Paris late last week. He is a real character who has given us so much joy and happiness. This is the first time he's seen and enjoyed the autumn leaves.

Heard of the FLEA yet? (Ultra simple rig)

http://ea3fxf.googlepages.com/flea has details of the superbly elegant rig from EA3FXF. Basically this is a simple QRP TX converted into a neat transceiver. The link has lots of information on this rig including a PCB layout and a SPICE (electronic simulation) file. There is also a Google Group on this little beauty although the correspondance is in Spanish. A full article on the FLEA is available at http://ea3fxf.googlepages.com/SPRAT-FLEA.doc . I think Eduardo and Joan must have prepared a SPRAT (G-QRP club mag) article.

Excellent stuff Eduardo, EA3GHS, and Joan, EA3FXF - a wonderful addition to the "ultra simple transceiver" line!

2nd QSO with FETer 80m micro transceiver

This morning I had a second QSO with the FETer 80m CW "micro rig" which uses just 14 parts in total plus earpiece and morse key. The QSO was with M0DRK in the village and the report again S9 suggesting contacts at further distances are certainly possible. I would welcome skeds with stations between 10-30 miles from my QTH (JO02DG in East Cambs) to check daytime range.

This is SUCH fun and proves that solid, reliable contacts can be made with next to nothing. In all, the parts cost about £5.

1 FET transceiver .....QSO No 1

Managed a solid RST598 (yes 8 - a little chirp) QSO on 3.579MHz with M0BXT tonight when I was running just my 14 component MPF102 FET transceiver tonight.

The regen RX in this works extremely well and is pulling in loads of 80m CW and SSB stations at good volume in the crystal earpiece. The TX uses only 4 parts including the crystal!

Now THIS is real ham radio - solid contacts with a tiny, simple, rig that can be built, with brand new parts for about £5.

Cycle 24 ....starting at last??

http://www.dxlc.com/solar/

If you look at the solar flux and sunspot count I do believe, at long last, there are real signs of a climb out of the long sunspot minimum. There have been several false dawns already, but I think this is really it.

LATER: more spots have appeared!

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.