10m FT8 TX (for a change!) - Saturday

For a change, I am on 10m FT8 transmit with the FT817ND and the tiny indoor loop with the wire inductor. This is less good than the copper central heating pipe inductor, but I was concerned with RF voltages on the higher Q loop on TX. In RX, of course, this does not matter So far, nobody has spotted me on TX today.

UPDATE 1324z:  As nobody spotted me on TX, so I am on RX only at present with the FT817ND and the loop. Perhaps I should put the higher Q inductor back on the loop?

UPDATE 14303z: K5YCM (7275km) spotted amongst 83 stations so far copied. At first I thought he was a pirate, but he seems to have been spotted by many in the USA and Europe so may well be genuine.

472kHz TX in the last 2 weeks

472kHz unique spots in last 2 weeks of my 5mW ERP signal

These are the unique spots I have received for my 5mW ERP 472kHz WSPR signal in the last 2 weeks. At some point I must work out how many unique WSPR spots I have received this season.

Last winter my 5mW ERP from the earth-electrode "antenna" was spotted over 1000km away.

Super simple FM TX - try on 2m?

See http://makezine.com/projects/super-simple-fm-transmitter/ .

This is a super simple TX for Band II FM using readily available parts.  With a smaller coil (1 turn less) and C4 smaller (and made tunable) I think it could be used experimentally on 2m FM, but stability is likely to be poor, so really only of use for short range and short durations.  From here, I'd expect this to be detectable at least 3km away (next village) even if the power is at uW or low mW levels. A few uW go a LONG way if connected to a reasonable antenna like my V2000 or 3el beam. There is no harmonic filtering either: a small low pass filter is advisable really.

With lower modulation levels (adjust) it should be fine with NBFM. The 2N3904 is a ubiquitous transistor available for just a few pence from many sources. The other parts are just pence.

Image at http://makezineblog.files.wordpress.com/2013/10/kogawa_simplest_transmitter.png?w=620&h=354

My thanks to Southgate Amateur Radio News for finding this before me.