Wadley Loop [SEP] named after
Wadley loop
The Wadley loop circuit was designed by Dr. Trevor Wadley in the 1940s in South Africa and was first used for a stable Wavemeter.
Overview.
In a traditional superheterodyne radio receiver, most oscillator drift and instability occurs in the first frequency converter stage, because it is tunable and operating at a high frequency. In theory, if one can eliminate this drift, the receiver will be stable.
Unlike other drift-reducing techniques (such as crystal control or frequency synthesis), the Wadley Loop does
50 and 600 kilometers. This information gives insight into what is occurring during an ionospheric storm. The ionosonde was used to provide a transmission frequency prediction service to the SABC, the South African Postal Service (SAPO) and South African Military.
Wadley loop.
It was in 1948 at the CSIR that Wadley invented the Wadley Loop receiver, which allowed precision tuning over wide bands, a task that had previously required switching out multiple crystals. The Wadley Loop was first used in the Racal RA-17 a 1950s top-of