1. “Kitchen Sink” Radio An approach to ham radio fun without complexity Roger G3XBM www.g3xbm.co.uk A talk given at the Cambridge Radio Club on 12.1.07 © Roger Lapthorn 2007

2. Tonight My approach Homebrew techniques Ideas for homebrew fun Useful links Good kits Commercial rigs

3. My Ethos Modest power Simple equipment Simple antennas Small is beautiful Simplicity is elegance Just enough technology

4. Homebrew Approach Bursts of energy – long periods without building anything sadly Go for projects that will get finished PCBs not required for “one offs” Projects don’t need lots of test gear. Go for good kits Hasn’t got to be amateur radio related. Use the gear you make/own.

5. Components Choice Ugly construction Discrete parts VXO/crystal controlled Standardise on parts: 2N3904/6, MPF102, T50-2, T50-6, 0.1u, 10u, 1k, 10k etc Re-use parts Recycle boxes

6. The Humble Crystal Set Simplest radios to get going Possible to hear real BC DX on HF More to them than you might think Amateur band DX? -55dBm

7. 40m Regen Receiver 9 parts, works well CW/SSB, -85dBm

8. VLF/LF Converter

9. Micro 80 4 transistor HF transceiver PA is the mixer

10. Pixie 250mW HF transceiver PA is the mixer Breakthrough problems

11. OXO HF QRP Transmitter Any HF band, 1W, VXO controlled

12. Pipit 15m CW transceiver

13. Kitten 10m CW transceiver Pipit derived cct. 0.5W RF out 0.5uV sens. Full break-in 25kHz VXO 5 transistors

14. Fredbox

15. Earth Mode Communications Communicating at <10kHz through the ground Use audio power amps and ground rods Ranges 0-10kms (typically <1km) PC based RX/filters & QRSS for >>range

16. Useful “Simple” Links HOMEBREW –GQRP club www.gqrp.com/www.gqrp.com/ –Rick Anderson www.tricountyi.net/~randerse/radios.htmwww.tricountyi.net/~randerse/radios.htm –JF1OZL www.intio.or.jp/jf10zl/www.intio.or.jp/jf10zl/ –Harry Lythallweb.telia.com/~u85920178/web.telia.com/~u85920178/ –Gollum’s Xtal RXwww.oldradioworld.de/gollum/index.htmlwww.oldradioworld.de/gollum/index.html –Hans Summerswww.100megsfree2.com/hans/www.100megsfree2.com/hans/ –N4DKDwww.n4dkd.com/www.n4dkd.com/ –G3XBMwww.g3xbm.co.ukwww.g3xbm.co.uk KITS –Elecraftwww.elecraft.comwww.elecraft.com –Small Wonder www.smallwonderlabs.com/www.smallwonderlabs.com/ –Hendricks QRPwww.qrpkits.com/www.qrpkits.com/

17. Some Good Kits MFJ Cub Elecraft T1 ATU Elecraft K1 and K2 Hendricks kits

18. MFJ Cub 15m 1W QRP CW 8000kms DX with a dipole Easy 3-4 hour build Decent superhet RX

19. Elecraft T1 Auto-ATU Matches 160-6m Instant retune when band changing FT817 No-hands retune from 80-10m 6hrs build

20. Elecraft K1 4 band CW Transceiver A “work in progress” Kit in the Heathkit style 5W on 40, 30, 20,15m Narrow CW filters Keyer + beacon modes Auto-ATU

21. Elecraft K2 The best kit in the world producing a first class HF transceiver

22. Future projects? Complete the 1 transistor transceiver QRP 10m SSB phasing transceiver PSK16/31 earth comms rig 136kHz (or 500kHz) activity 4m transverter 10m halo 2m/70cms SSB Another Fredbox (DSB?)

23. Commercial Rigs FT817, IC703, VX2. Avoid costly “soon get bored with” rigs. “Shack” fits a desk in bedroom corner 80m to 70cms rigs and antennas Multi-band simple WIRE antennas. VHF/UHF vertical – Spor-E on 6m

24. FT817 Simply the best HF/VHF rig for the price Worked 4 continents on SSB handheld!

25. Miracle Whip Auto-transformer matched 1.5m whip With counterpoise is 2 S-points (12dB) down on a decent vertical DX 11000kms from the bedroom table with 5W SSB!

26. IC703 First class QRP radio 0-10W 160-6m Speech processor Auto ATU DSP filters

27. VX2 Yaesu 2m/70cms Low cost tiny VHF/UHF handheld Pocket sized Good performance with longer whip Good for holidays Get a programmer

28. Summary Build something simple next weekend Nice to own a few commercial rigs DXCC with QRP (mainly SSB) possible with simple antennas (even handheld) Operate – use the bands Call CQ Diversify Have fun!