G0SFJ's Lab Notes

From time-to-time Andy, G0SFJ circulates small Lab Notes and other articles to Club members.

We are now publishing these on the Website, thereby increasing the potential audience for these gems.

Andy, G0SFJ, would welcome any comments and developments of these "Lab Reports". He is QTHR on QRZ.com.

Investigating a donated German Second World War era Absorption frequency meter.

Dating from 1941 this absorption wavemeter would have be used by the Wehrmacht.

An article about the conservation of two Ex-air force VHF transmitters, again dating from the Second World War. They are both USAAF Type SCR-522 (also known by the British as BC-624)

It explores and documents their features and extrapolates to their use in amateur radio.

Repair or Restoration?

Replacing the missing spark protector for a double-current Morse Key, used in trans-oceanic telegraph circuits & dating from 1914.

Lab Report: The “Vollnetz” Valve Tester of 1938/9.
The Excelsior-Kiesewetter Vollnetz 35D was a compact, versatile vacuum tube tester manufactured by Excelsior-Werke Rudolf Kiesewetter, Leipzig.
Built in the late 1930s (approx. 1936–1939), it allowed users to test tubes, measure voltage, and check current both inside radios and in independent tube circuits

An article on Restoring a Soviet VHF radio tester IK-2

A three part instrument consisting of a Signal Generator, a Crystal Calibrator, and a Frequency Deviation Meter.

An article about Coil used in the Marconi SWB HF transmitter, originally produced in the late 1930s. Obtained at the J28 rally.

What is Neutralizing? When was it necessary? Find out in this Lab Report.

For some time now G0SFJ has been revisiting old technology – that of the thermionic valve. Here are two simple projects he has built.

An article about some rare Japanese wartime kit that has caught G0SFJ’s eye.

Obtained from eBay in the UK and just described as a lock from a WW2 German wooden box.

Are these from a WW2 Enigma machine ?

Hudson transceiver, without the handset, on sale for just £1 at a recent rally in King’s Lynn.