Chinese QRP transceivers

In my recent analysis of good value QRP radios I ignored the recent Chinese entries into the market. As far as I can see, these are still immature products, but they are getting better by the day. For example, see http://www.wouxun.us/item.php?item_id=302 . I judge this by how prepared would I be to buy a Chinese radio. The answer is not yet.

10m still brilliant

As 6m WSPR was only giving me inter-G signals today, I switched to 10m. The band is still wide open to North America and has been whenever I have checked in recent afternoons. Not one report  is from less than 5000km with 2W. Sunspot count is 178 which helps to explain the good conditions of late.  The good times will not last: make the most of them as it may be a long wait.

At 1716z the 10m band was still wide open to the USA, in total darkness here.Then the band just died for me here in East Cambridgeshire. And then, a full hour later KB9AMG (6300km away) and W8AC spot me at -22dB S/N. And it has been dark here since 1630z! At the moment it looks as if the band finally died cross-pond at around 1830z -very late for 10m.

Micro-40 DSB build

http://aa7ee.wordpress.com/2013/10/19/the-vk3ye-micro-40-dsb-transceiver/ has a beautiful description of the building of this little transceiver using Me-squares. There is  a complete walk-through of AA7EE's build - truly beautiful workmanship.

6m and 2m inter-G WSPR

Although inter-G DX is possible on 2m WSPR (witness the tests between G3XBM and G3WKW over a 134km path on 2m recently with 2W and a halo) the equipment drift and Doppler shift makes WSPR a marginal mode on 2m. Things on 6m are better and longish paths are possible.See the 6m WSPR results today so far below:

So far, only inter-G paths seem to be open on 6m today. The high drift figures are almost certainly due to aircraft Doppler.

Best value new QRP transenceivers

At  the moment the running order, ignoring wSDR designs, is:

• Elecraft KX3  - best RX, expensive with all options in the UK. n ternal auto-ATU option
• Ten-Tec Argonaut VI - excellent RX and ideal base station but no  5,24 or 50MHz coverage.Expensive.
• Yaesu FT817ND - excellent base/portable unit up to 432MHz,but RX not as good as KX3 or Argonaut VI. 13-14 year old design.
• Icom IC703 - excellent base transceiver,but no longer available new. Internal auto-ATU.

Overall, the FT817ND represents best value for money all things considered, in my view. It may be an old design but I can buy 2 FT817ND with plenty of change for the price of the KX3. And I get a better design for home station digital (WSPR) use with botj 144 + 432MHz bands. Even adding a Z817 or T1 auto-ATU to the price of the FT817ND units there is still change when compared with the fully loaded KX3.

Reviews on www.eham.net are similar for all radios listed.

10m still wide open

My first 10m WSPR transmission with 2W to a small antenna after lunch was copied in the  middle of the USA, in Canada, Israel and South Africa. Sunspot count today is 196. Conditions appear to be very good  still.

Oscilloscope-watch

John Mullin sent me this link which may amuse you.It describes a wrist wearable scope and frequency counter for $150.

http://www.ae5x.com/blog/2014/01/07/an-oscilloscopefreq-counter-on-your-wrist

First 2m WSPR results

This evening I got my first WSPR spot on 2m from G3WKW at 134km the other side of London in North East Hampshire. It was hard work with the unmodified FT817 because of frequency error,  drift, Doppler etc. Bob was visible with me but no decodes of his signal.

We should manage a 2-way QSO in due course with a more suitable mode. I was using 2W to a halo antenna. Bob was using 5W and a small beam.

The  next night I managed to decode Bob's signal (once only) although he was visible on most transmissions  but not decoding because of the Doppler shift.

NB post updated as I had G3WKW in the wrong county!

10m - often open

Although we are currently enjoying decent F2 long distance propagation on 10m, we must not forget that the 10m band is FREQUENTLY open by Es (sporadic-E) propagation.

The best months in the northern hemisphere are between late April and early September but the propagation can occur at any time of the year. This is very much a case where WSPR will be useful to winkle out brief periods of Es propagation. Sometimes multi-hop Es allows real DX to be workable.

Often Es signals can be very strong, but sometimes openings can be very, well, sporadic open briefly to one place with signals inaudible just tens of miles away.   In many ways Es is a more fascinating mode than F layer and one of the reasons 10m is my favorite band of all. Don't also forget inter-G propagation. In RSGB contests a few years ago it was possible to work out to around 100 miles with 10W SSB to dipole antennas. Imagine what the inter-G range will be with WSPR.

Beach 40 - a 40m DSB rig

Andrew,G6ALB, has introduced me to this simple DSB project. See http://www.youtube.com/watch?v=siSgeljr4HE and similar links for pictures and build instructions. See also http://www.spencerweb.net/Ian_and_Julie/Hobbies/Amateur_Radio/Beach_40/beach_40.html .

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKDrYOQV_BeUXub1PXz3HioLns_htLBhUkI6YKyH3V73luFIcEmefzF6dEzZDirqzW1Rv0ybz1KbbxADnGSb760kzc3IxWVwKtFVaN-j0cAo91_oHIBn3yY_oVR6u_xjqaM4AiP9tGF9N_/s1600/carrier_gen_balmod_audio.GIF

The schematic above does not show the simple PA,