The John Welsh Collection

Introduction
Introduction

A Short History Of Radio
Earliest Times
Late 19th Early 20th Century
Early Last Century
Did Marconi really hear those Transatlantic signals?
The Tuned Spark Transmitter
The Coming of the Diode
The Triode, the start of modern electronics

Historic Electronics
Tesla Etcetera (Part 1)
Tesla Etcetera (Part 2)
Tesla Etcetera (Part 3)
Tesla Etcetera (Part 4)
The Thermionic Diode
The Triode Valve
The Klystron
The Klystron – Addendum
The Magnetron
The Magnetron Addendum

Principles
Analogies of Electricity Part 1
Analogies of Electricity Part 2
Scale: Some Numbers
A Crystal Set
The Electron
Wire Baluns (Part 1)
Wire Baluns (Part 2
Transmitter Impedance
The ‘Q’ of a Tuned Circuit
The Phase Locked Loop
The dbs
Units Of Measurement
Lead Acid Batteries
The Microphone
Thoughts on the Magnetic Field in a Toroid

Componants
The Transistor
The Semiconductor Diode
Capacitors (Part 1)
Capacitors (Part 2)
Resistors
Inductors
Ferriteless Toroids
The Thyristor

Aerials
Aerial Gain
The Dipole
Low Frequency Aerials
Shortend Dipole – pt1
Shortend Dipole – pt2
Low Frequency Aerials
Off Centre Fed Aerials
Aerials for Circular Polorisation
Loading Of Aerials
Traps In Aerials
Wave Polorisation (Part 1)
Wave Polorisation (Part 2)
Aerials and their Q
Monopoles and Earth Image
Radiation From A Wire

Feeders
Aerial Feeders
Coax – Does Size Matter?
Coax Calculations
Coax Impedance – Power
Coax Impedance – Loss
Skin Effect
Standing Waves (Part 1)
Standing Waves (Part 2)
Transmission Lines

Earth
Earth Image
The Measurement Of Earth Resisitance
The Importance Of A Good Earth At Low Frequencies
Monopoles and Earth Image

Operating
Are You Getting Out? The Sniffer Box
The Evolution Of Morse Code In Radio Science
Slow Morse (Part 1)
QRSS – Noise (Part 2)
Back To QRSS – (Part 3)
Q Codes

Other
Atmospheric Attenuation
Impedance Of Free Space (Part 1)
Impedance Of Free Space (Part 2)
Impedance Of Free Space (Part 3)
Impedance Of Free Space (Part 4)

60m Operating

Amateur radio operators are reminded to take care when operating on the WRC-15 secondary amateur allocation at 5MHz. The UK still has no access to the full WRC-15 allocation. Despite requests, this seems unlikely to change in the foreseeable future. Whilst the UK is fortunate to have more generous licence conditions, it is imperative these ... Read more

VARC AGM

Our February monthly meeting included our Annual General Meeting (AGM) where the Committee for the next Club year remained much the same but with the addition of Steve G5SRO joining the team as Publicity officer. We also took a looked at our subscriptions and it was decided for this year to keep them at the ... Read more

200 Years of Train Travel

BRARS is running special event station GB0LMR during 2025 to celebrate 200 years of train travel since 1825. Operation will be focused on the 40 and 10m bands and QSL will be via the Bureau. More information is available at QRZ.com and webrars.info.

Special Event Station PA80OV

PA80OV is a special event station to commemorate Operation Veritable. Operation Veritable, namesake of the station and the successor of Operation Market Garden, was the northern part of an Allied pincer movement in the Second World War. Members of the Radio Club Limburg will activate the PA80OV callsign from 13th to 28th February 2025 and ... Read more

TM22AAW

Listen out for special event station TM22AAW which will be on the air on 8th to 20th February. The station will be active in celebration of the 22th Antarctic Activity Week. More information about the station is available at qrz.com/db/TM22AAW. The new reference for Worldwide Antarctic Program is 354. QSL via F8DVD, directly or via ... Read more

World Thinking Day

Don’t forget that Girlguiding groups will be taking part in World Thinking Day on the Air activities over the weekends of the 15th and 22nd of February. The aim of the event is to encourage Girlguiding members to make friendships with those in other units, using amateur radio as the means of communication. A list ... Read more

Inspiring Newcomers

Have you been involved in inspiring newcomers to amateur radio? Do you have a knack for introducing and explaining the fundamental principles of our wonderful pastime to the uninitiated? If so, have you considered writing for RadCom Basics? Tim, G5TM, the RadCom Basics Editor, welcomes all suggestions. If you have ideas for future articles, email ... Read more

World Wide Award

Lots of operators are on the air, until the end of January, with stations taking part in the World Wide Award. If you have been listening to the HF bands, you will have heard lots of stations using callsigns with a WWA suffix. Points are awarded for working these stations using a variety of modes. ... Read more

Simplification of licensing for overseas visitors

Ofcom has announced a consultation which seeks to simplify the licensing of amateur radio visitors to the UK from a specified list of countries. The consultation also covers the proposed simplification of other wireless equipment usage. Ofcom says: “We propose to introduce a new licence exemption for short-term use of radio amateur equipment by radio ... Read more

Thinking Day On The Air

On the 15th of February, Girlguiding members will celebrate World Thinking Day on the Air. The aim of this event is to encourage Girlguiding members to make friendships with those in other units, using amateur radio as the means of communication. On this day, Crawley Amateur Radio Club and RSGB volunteers will be hosting special ... Read more
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