Ham radio fun without complexity Roger G3XBM www.g3xbm.co.uk “Kitchen Sink” Radio Ham radio fun without complexity Roger G3XBM www.g3xbm.co.uk
Tonight My approach Homebrew techniques Ideas for homebrew fun Useful links Good kits Good value commercial rigs
My Ethos Modest power Simple equipment Simple antennas Small is beautiful Simplicity is elegance Don’t waste money
Homebrew Approach Bursts of energy – long gaps without building much Go for projects that will get finished PCBs not required for “one offs” Projects that 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.
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
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 reception possible -55dBm
40m Regen Receiver 9 parts, works well CW/SSB, -100dBm
Single FET transceiver Sensitive, stable, non-fiddly, regen RX 1 active device Stable, crystal controlled, TX 14 parts !
VLF/LF Converter
Micro 80 4 transistor HF transceiver PA is the mixer
Pixie 250mW HF transceiver PA is the mixer Breakthrough problems
OXO HF QRP Transmitter Any HF band, 1W, VXO controlled
Pipit 15m CW transceiver
Kitten 10m CW transceiver Pipit derived cct. 0.5W RF out 0.5uV sens. Full break-in 25kHz VXO 5 transistors
Fredbox 2m Transceiver
Homebase 10 Antenna Simple horizontal halo for 28MHz Low cost, easy to build and tune up Works well
70cms Moxon Antenna Made in 30 mins from a metal coat hanger ! 3-4dB forward gain 100 degree -3dB points Best DX 327kms with 5W
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 greater range
Useful “Simple” Links HOMEBREW GQRP club www.gqrp.com/ Rick Anderson www.tricountyi.net/~randerse/radios.htm JF1OZL www.intio.or.jp/jf10zl/ Harry Lythall web.telia.com/~u85920178/ Gollum’s Xtal RX www.oldradioworld.de/gollum/index.html Hans Summers www.100megsfree2.com/hans/ N4DKD www.n4dkd.com/ G3XBM www.g3xbm.co.uk KITS Elecraft www.elecraft.com Small Wonder www.smallwonderlabs.com/ Hendricks QRP www.qrpkits.com/
Some Good Kits MFJ Cub Elecraft T1 ATU Elecraft K1, K2 and K3 Hendricks kits SoftRock RX
MFJ Cub 15m 1W QRP CW 8000kms DX with a dipole Easy 3-4 hour build Decent superhet RX
Elecraft T1 Auto-ATU Matches 160-6m Instant retune when band changing FT817 No-hands retune from 80-10m 6hrs build
Elecraft K1 4 band CW Transceiver Excellent kit in the Heathkit style 5W on 40, 30, 20,15m Narrow CW filters Keyer + memory modes Auto-ATU Works well
Elecraft K2 “The best kit in the world producing a first class HF transceiver” K3 now available
Future projects 500kHz QRP TX 10m QRP DSB transceiver Improved single FET transceiver A DSB Fredbox Earthmode comms tests with QRSS
The G3XBM Shack Fits in corner of spare bedroom Homebrew rigs plus FT817 and IC703 “Lab” in back of the garage
FT817 Simply the best HF/VHF rig for the price Worked 4 continents on SSB handheld!
Miracle Whip Auto-transformer matched 1.5m whip With counterpoise is just 2 S-points (12dB) down on a decent vertical DX 11000kms from the bedroom table with 5W SSB!
IC703 First class QRP radio 0.5 - 10W 160-6m Speech processor Auto ATU DSP filters
Summary Build something simple this weekend! Nice to own a few commercial rigs DXCC with QRP SSB and CW possible with simple antennas (even handheld) Operate – use the bands Call CQ Diversify Have fun!