Ferrets, rats and crabs…..and CATs too. Getting the best from a limited QTH David Aslin G3WGN TARS Meeting August 28 th 2015

 1961 Introduction to radio  1963 Joined RSGB as SWL A4677  1967 Licensed as G3WGN, aged 16  & 80 only; home-brew TX 10W; AR88D and Lafayette KT-320  NFDs, GB3MCG; first commercial rig: Yaesu FT W  Work, family, work, family…  QRP, DX and contests; 80m DXer  WJ6O in Silicon Valley; hired gun contest operator  G3WGN and M6O Devon; search for DX & contest site G3WGN background

From This… G3WGN/Warwickshire 1968 Sshh! don’t mention the Joystick!

…To This… G3WGN GQRP 5278 Cheshire 1978 Elecraft K2 10W Homebrew 1W on 40m Lafayette KT-320

…To This… M6T 1998

…To This… G3WGN Herefordshire 1998 Yaesu FT1000MP (now with G6GLP!) Heatherlite Explorer then ACOM 2000A 220 countries on 80m in 3 years

Go West young man…

…To This… N6RO 2002 N6RO

…Then This… K6IDX K6IDX

…and This... WC6H

…and Back Again G3WGN Spreyton 2015

 Escape noise, small garden, lousy site, weather, XYL…  TK/G3WGN  SV8/G3WGN EU-072  T32C  Dartmoor – SOTA High Willhays  TX6G  E6GG September 15 th - 29 th 2015 Globetrotting

 Successful stations plan antennas as a SYSTEM  Optimise what you have:  Pick the right antenna  Pick the right feeder  Look after your feeder  Kill that noise Lessons learned

Antenna System Design Ground-mounted Vertical  Feed with 20m Westflex 103  Antenna gain: -2.4dBd  Coax loss: -0.32dB  System gain: -2.72dBd Dipole at 9m  Feed with 20m RG58 + another 10m RG58 up the mast  Antenna gain: 0dBd  Coax loss: -2.5dB  System gain: -2.5dBd

Antenna System Design Dipole at 9m  Feed with 20m Westflex m W103 up the mast  Antenna gain: 0dBd  Coax loss: -0.48dB  System gain : -0.48dBd 2 element YAGI at 9m  Feed with 20m RG m RG58 up the mast  Antenna gain: 4dBd  Coax loss: -2.5dB  System gain: +1.5dBd

 What’s the terrain like?  Model antenna versus height versus direction with HFTA by N6BV  Put the antenna at the optimum height if you can  If you need radials, use plenty – they don’t have to be long if you don’t have space  If you have a choice of location match it to the antenna type Pick the right antenna

 Major performance impact:  Antenna  Support  Terrain  Feeder  Matching  Grounding  Minor performance impact (<100MHz):  Connectors  Documentation  Maintenance The antenna system

Antennas on the beach Vertical Dipole Arrays 17m and 10m at TX6G

Where to next? E6GG North Coast of Niue What’s missing?

Where to next? E6GG North Coast of Niue What’s missing? NO BEACH!

Antenna Choices TX6G  Lots of beach – verticals by the sea!  Shacks next to the beach  Lots of nearby noise sources  VDAs for 10 through 20m  Elevated quarter waves for 40 and 30m  Vertical/inverted-L for 80/160m  Pennant for RX E6GG  No beach; 25m high cliffs  Shack 140m from sea  Low noise site?  Dipoles for 10 through 20m, 1.0λ high  Elevated quarter waves for 160 through 30m  Beverages for RX Horses for courses

Antenna at home

Folding Hexbeam 2 elements per band m G3TXQ electrical design Folding Antennas DL1LEU manufacturer

Does it work? 2015: 220 DXCC entities/countries 900 band slots 21 countries on 6m

Actually, anything works W lightbulbs in phased array by Tom Schiller N6BT Tom is former founder/owner of Force 12 antennas

Actually, anything works - 2 Enjoyment vs antenna type according to N6BT

 Don’t waste power or signal  Feeder is cheaper and easier than big antennas and can have more gain!  Unless you have very short runs or are on 160m, RG58 or Mini-8 are almost never the right choice:  1950s product, no longer made to MilSpec  Poor screening  High losses on HF  Modern coax is much better:  Aircell 5 or Aircell 7 (Nevada);  Airborne 5 or Ultraflex 7 (Martin Lynch)  Even better: Westflex 103 (Henry Westlake) Pick the right feeder

Feeder loss matters Running 100Watts? Here’s what is at your antenna: 1dB loss (40ft/12m RG58 at 10m)80W 2dB loss (160ft/25m RG213 at 10m)63W 3dB loss(120ft/36m RG58 at 10m)50W Or, if you have 40ft feeder: RG58: 10m band have 80W at the antenna RG213: 10m band have 89W at the antenna W103: 10m band have 95.5W at the antenna Feeder change brings the cheapest dB you can have!

 Take measurements so you can spot changes  Inspect regularly  Use high quality connectors, properly waterproofed  Everything wants to get into your coax  Water  Salt  Critters Look after your feeder

Flushed with success at T32C

Rats! In UK: Squirrels? Pets? Enthusiastic gardeners?

 We are trying to optimise SYSTEM performance, not just antenna performance  20dB (S3) of noise makes 1kW seem like 1W  Reducing noise by 6dB is like swapping your dipole for a 3 or 4 element beam  Verticals are great for picking up noise, go horizontal at home if you can  Don’t let common mode noise ruin your day or DX Opportunity: W 0 GJ at the RSGB Convention: Is 3dB worth a divorce? Kill that noise

 ‘Electronic smog’ is everywhere, but you can tame (some of) it  Feeders don’t only feed signals, they feed noise unless you stop them  Keep noise out with ferrets  At antenna feedpoint  At shack entry point  On mains cables and interconnects Dealing with noise

The Reverend Jim K9YC Ferret trainer extraordinaire

K9YC ferrite chokes Use FT toroids or Type -31 clip-ons Put enough turns on! HF 3-5LF 5-9+ See Jim’s Cookbook audiosystemsgroup.com/RFI-Ham.pdf

Ian GM3SEK Honey, I shrunk the ferrets!

M 0 PCB version of GM3SEK ferrite choke

 Try stuff – you may like it  Competing with yourself drives continuous improvement  Simple wire antennas work  Pick the right antenna for your location  Choose the right feeder and look after it  Kill that noise  If all else fails, operate from somewhere else… Lessons

What about the CATs? I thought you said there’d be CATs?

CAT – station automation

CAT – Computer Aided Transceiver

 Vertical dipole arrays: RadCom December 2014, p34 and  Folding Antennas Hexbeam: RadCom April 2015, p26 and  HFTA by N6BV: ARRL Antenna Book 21st-23rd Editions  Ferrite chokes:  K9YC: audiosystemsgroup.com/RFI-Ham.pdf  K9YC: audiosystemsgroup.com/CoaxChokesPPT.pdf  GM3SEK:  Finding and killing noise:  “Everything works” N6BT: Further Reading

Questions?

Where to next? E6GG North Coast of Niue 6Gs team that brought you TX6G last year September