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)

Jamboree on the Air

Jamboree on the Air, also known as JOTA, is taking place between the 18th and 20th of October. The event promotes friendship and global citizenship and is a brilliant celebration of amateur radio among the groups within the Scout Association. Some groups have already shared details of activities that will be taking place over the ... Read more

Bletchley Park

1940s Weekend! 21st / 22nd Sept’ Fun for all the family, this two-day event in September is a chance to step back in time and enjoy a marvellous weekend of vintage entertainment. Why not dress to impress and visit us in 1940s attire? Enjoy live music throughout the weekend and visit the market stalls and ... Read more

Ofcom – Revalidation Video

Ofcom has released a new step-by-step video on its YouTube channel to assist radio amateurs in the process of revalidating a UK amateur radio licence using the online licensing portal. Ofcom does note that whilst it is a requirement to revalidate your licence every five years, it is recommended to do it annually. Make sure ... Read more

The RSGB Youngsters on the Air

The RSGB Youngsters on the Air representative Rhys Williams, M0WGY, arrived in Prague, Czechia on Friday the 16th of August for this year’s YOTA summer camp. The camp is organised by the IARU Region 1 Youth Working Group together with the Czech Radio Club and finishes on Friday the 23rd of August. These camps offer ... Read more

Lighthouses, Lightships and Waterways on the air

Don’t forget to listen out for all the stations that will be on the air during International Lighthouse and Lightship Weekend on Saturday the 17th and Sunday the 18th of August. This is one of the most popular amateur radio events in the calendar and in past years there have been more than 500 entries ... Read more

International Jamboree

From the 27th of July to the 3rd of August, the Essex International Jamboree is welcoming around 10,000 scouts and guides, including 2,000 supporting volunteers from around the world, to Boyton Cross near Chelmsford. As part of the programme, amateur radio station GB24EIJ will be running a wide range of communications and electronics activities. The ... Read more

NRC Volunteers

There are vacancies for licensed radio amateurs to volunteer for the RSGB at the National Radio centre at Bletchley Park. Expenses paid. Interested? Please email Martyn Baker G0GMB at martyn.baker@rsgb.org.uk

GR2HQ

Don’t forget you can get involved in the new GR2HQ Challenge next weekend, the 13th and 14th of July, as part of the IARU HF World Championship contest. You can take part as individuals but also benefit your club, so why not encourage your club members to take part whether they are regular contesters or ... Read more

TX Factor – 10 years and 30 Episodes.

TX Factor is marking its ten-year anniversary by launching its 30th episode. It looks at how radio technology has advanced since Marconi conducted some of his early transmissions. The episode includes the first of a two-part feature on operating via the QO-100 geostationary satellite with a look at the hardware and software needed to achieve ... Read more

The RSGB’s National Radio Centre will be operating special event callsign GB2DAY to commemorate the 80th anniversary of the D-Day landings during World War Two. The station will be active between the 6th and 9th of June. In addition, volunteers will be hosting the special demonstration station GB1SOE on Saturday the 15th of June. Don’t ... Read more
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