RadCom May 2015, Vol. 91, No. 5

| April 22, 2015

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Cover of May 2015 RadCom - Cover image: Force 12 XR6/XRGC Yagi feed arrangement. Photo by Steve Nichols, G0KYA

News and Reports

6 RSGB Matters
RSGB supporting ISS mission, invitation to apply for Legacy funding, Foundation and Intermediate operating abroad, committee and volunteer spotlights, AGM details, new experimental spectrum at 4m, Club of the Year top three revealed, RadCom Plus to launch, President’s review of contesting, new Twitter profile, training news, G3AAT SK, QSL Matters, congratulations and welcome
13 News
All the amateur radio news
14 New Products
The latest news from the amateur and technical market
81 Around Your Region
Our regular round-up of club diaries and news reports

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Reviews

32 Force 12 XR6/XR6C Yagi
Steve Nichols, G0KYA reports on a new 11 element antenna that covers six bands
56 Spiderbeam Aerial-51 Model 404-UL
Ultra-lightweight portable antenna for 40m-6m reviewed by Steve Nichols, G0KYA
59 Book Review
Giles Read, G1MFG enjoys the international flavour of Novel Antennas and is amazed by photos and stories of secret Cold War bunkers

Features

16 GB50LM
Special event station at the RSPB reserve at Leighton Moss described by Chris Baker, G4LDS
46 Thinking Day on the Air
Girlguiding celebrates its founder’s birthday each February and we hear from eight special event stations helping with the festivities
54 STELAR
Richard Horton, G3XWH reports the latest news of Science and Technology Through Educational Links with Amateur Radio
68 Commemorating British Radar
Graham Murchie, G4FSG and Brian Leathley-Andrew, G8GMU report from GB8ORE at Bawdsey marking the 80th anniversary of the original radar experiments

Technical Features

18 Homebrew
Transmit stages and filtering for the 10m transceiver project by Eamon Skelton, EI9GQ
23 Arduino-based Panadapter
Barry Chambers, G8AGN describes his live spectrum and waterfall display that works without a PC
38 A 23cm Linear Amplifier
A surplus transistor, internally matched for a different band, makes a fine 23cm 30W+ linear at low cost writes Stuart Wisher, G8CWY
42 Single 50 Ohm Feed for a 2-ele Dual Band Quad
Bob Cox, G3PLP describes his homebrew diplexer to run 10m and 6m antennas on one coax
44 Moving On
The second and final part of the explanation of baluns by John Welsh, G0NVZ
76 Design Notes
Andy Talbot, G4JNT takes a good look at accurate RF power measurement and takes a further glance at noise

Regulars

91 Advertisers’ index
36 Antennas, Peter Dodd, G3LDO
74 ARDF, Vlad Boev, 2E0VLB
34 ATV, Dave Mann, G8ADM
66 GHz Bands, Dr John Worsnop, G4BAO
60 HF, Martin Atherton, G3ZAY
92 Members’ Ads, Rallies and Events, Silent Keys, Special Event Stations
80 Propagation, Gwyn Williams, G4KFH
72 Sport Radio, Steve White, G3ZVW
96 The Last Word
64 VHF/UHF, Richard Staples, G4HGI

Category: Front Page News, RadCom