RadCom January 2015, Vol. 91, No. 1

| December 22, 2014

Cover of January 2015 RadCom - Cover image: The Yaesu FTM-400DE dual band, dual mode mobile. Photo courtesy of G4WNC

News and Reports

6 RSGB Matters
Including recognising and encouraging volunteers, Arkwright Trust award, Youth Committee chairman, volunteer and committee spotlight, British Science Week, congratulations, joiners and rejoiners
13 News
All the amateur radio news
58 New Products
The latest news from the amateur market
John Simkins, G8IYS presents the results and highlights of this flagship RSGB contest
84 Around Your Region
Our regular round-up of club diaries and news reports

Read this edition online

You will need your RSGB Membership Services login, follow the link below or click the cover image to your right.


16 Yaesu FTM-400DE dual band, dual mode mobile
Mike Richards, G4WNC looks at the technology behind the Yaesu System Fusion and Graham Coomber, G0NBI tries the radio on the air
59 Book review
Two great value non-radio books enjoyed by Giles Read, G1MFG plus the top three books from 2014


26 On Great Blasket for IOTA 2014
Seán Donelan, EI4GK reports on the PL DX Group’s trip to the island for the 2014 IOTA contest
30 Getting started in… software defined radio (SDR)
Mike Richards, G4WNC describes the technology and how it can enhance your radio activities
44 JOTA 2014
Scouts and Guides around the world took part in Jamboree on the Air and Elaine Richards, G4LFM presents the reports from several groups, including
the Lithuanian Scouts

Technical Features

20 Modern frequency synthesisers
Based on his RSGB Convention talk, Andy Talbot, G4JNT explains the key concepts and architectures
40 Homebrew
Designing and building bridges for RF impedance measurement by Eamon Skelton, EI9GQ
56 Moving On
John Welsh, G0NVZ looks at the very large and very small numbers we use in radio and electronics
76 Design Notes
Andy Talbot, G4JNT looks at high performance receivers, an ideal bridge rectifier and an RF switch for low frequencies
78 A parallel filter architecture for flexible IF processing
Dr Paul Darlington, M0XPD questions why you would switch IF filters when you can switch IF frequency instead


91 Advertisers index
36 Antennas, Peter Dodd, G3LDO
74 ARDF, Bob Titterington, G3ORY
54 AT V, Dave Mann, G8ADM
66 GHz Bands, Dr John Worsnop, G4BAO
62 HF, Martin Atherton, G3ZAY
94 Members’ Ads, Rallies and Events, Silent Keys and Special Event stations
93 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