21MHz (15m) QRP CW - my homebrew "Pipit"

Many years ago I designed and made this QRP (800mW) CW rig of 15m. 

It worked remarkably well and worked some impressive DX. 

For several months it was the only rig I used, out of choice. Every QSO was so satisfying. It appeared in GQRP SPRAT. It was in the days before schematic drawing packages, so the schematic was hand-drawn. I used Neosid toroids as these were at hand, although I am sure Amidon ones would be suitable with turns adjusted.

Values are on my webpage. As with all my designs, please use this as a starting point for your own ideas and do not be afraid to change things if this makes the design better! The SBL1 mixer can certainly be replaced by similar double balanced mixers or a homebrew version.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/15m-qrp-cw-pipit .

Sputnik valve TX tests

This afternoon G6ALB and I got together to build a 2 valve 21MHz transmitter using a couple of Russian valves of the same types used in the original Sputnik 1 satellite in 1957. Surprisingly I've never built a valve transmitter before. Even today, Andrew did most of the building. My input was to wind a toroid and to help sort out the wire ends of the two valves. The valves were kindly supplied by Mike AA1TJ.  The breadboarded TX is shown in the picture. On a test this evening over the 3km path between our QTHs the 400mW TX was copied fine on my IC703 and 10m halo antenna.  Even at the lowest HT voltage (around 30V) his signal was still solid copy on the "Sputnik". Our aim is to have a pair of these units ready for Sputnik Day (Oct 4th) and to work each other and other more distant stations who are using similar rigs.  See also http://aa1tj.blogspot.com/2011/07/sputnik-qso-party-transmitter-prototype.html

QRP DXing on 15m CW

With the improved sunspot count yesterday and today 15m has opened up to the Caribbean and to the USA this afternoon. First QSO was 9Y4VU at 1400z then WX3B at 1450. Both were with 5W CW into my 500kHz vertical via the T1 auto-ATU.  I did take a quick look on 10m, but nothing heard hear. Later I took a go at PSK31 and worked RA3GI and US2IR on 15m with around 3W. It is so good to hear the higher HF bands coming back to life again: it has been a long time mostly quiet but the GOOD times are back.