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)

145 Alive – upcoming

The next in the series of the popular 145 Alive events, to promote the use of 145MHz FM, is coming up on Saturday the 11th of May, from 1pm to 3pm. The event and the supporting Facebook Group was started by Tim, G5TM and from the start of 2024 has been organised by Mark, M0XICand John, M0XJA. The last successful ... Read more

Blue Ham Exercise

The RAF Air Cadets are pleased to announce that they are running the ever-popular Blue Ham Radio Communications Exercise in June on the 60m band. The exercise will take place between the 17th and 21st of June. Subject to your licence conditions, the Blue Ham team hopes that you can put some time aside to ... Read more

Mills On The Air

Mills on the Air Weekend 2024 is coming up on Saturday the 11th and Sunday the 12th of May. The event takes place across the UK every May with more than 300 windmills and watermills usually taking part. For more information, to register, and to view a list of registered stations, visit ddars.net/mills.html

SOS Radio Week

SOS Radio Week is an annual event that takes place throughout the month of May to celebrate the work of the volunteers from the Royal National Lifeboat Institution, Independent Lifeboats and National Coastwatch Stations around the British Isles. Members of these organisations save many people between them who are in danger along and around the ... Read more

International Marconi Day

International Marconi Day will take place on Saturday the 27th of April. Once again, the Cornish Radio Amateur Club is organising and running the event. Lots of amateur radio stations will be operating from sites that Marconi operated from or had a personal connection with. For more information, and to view a list of the ... Read more

10m FM Activity day – 20/04/2024

A small group of Amateur Radio YouTubers have come up with idea of a 10m FM activity period, following in the footsteps of the 145Alive events that have been successful in promoting activity on 2m. Assuming this follows the format of the #145Alive events it is likely that a number of people in various parts ... Read more

Special event station GB0WYT

Special event station GB0WYT [GOLF-BRAVO-ZERO-WHISKEY-YANKEE-TANGO] will be active from RAF Wyton during the Airfields on the Air event on the weekend of the 13th and 14th of April. This is the 12th year that a special event station has marked the event. The callsign will again be operated by RAF Air Cadet Communication Staff and ... Read more

Dunstable Downs Car Boot Rally

NEW DATE – SAME VENUE Due to the Radio 1′ Big Weekend being held on the bank holiday weekend on the Stockwood Park site at the end of May, the Dustable Downs group have had to move their event to the 30th June. At the time of writing the RSGB rally calendar was clear but ... Read more

Changes To Ham Exam Fees

Early in February the RSGB announced that the fees for Foundation, Intermediate and Full level examinations would increase from the 1st of May 2024. You can now use the online booking system to book an exam prior to the 1st of May at the current price or select exam dates from the 1st of May ... Read more

RSGB video overview of Ofcom consultation results

Following Ofcom’s consultation on the amateur radio licence last year, it released a statement in December 2023. The statement outlined its decision to update the amateur radio licensing framework to ensure the policies and licences meet the needs of today’s and tomorrow’s radio amateurs, while streamlining the licensing process. It also published a General Notice, ... Read more
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