Mullard thermionic valve from National Valve Museum:
The 2D4A valve houses a pair of signal diodes with a common cathode. The valve design is from 1934 and the diodes would have been used for demodulation at, probably at around 455 - 500 kHz, the IF frequency of broadcast radio receivers.
- Radio Communication
- Object Number:
- thermionic valve
- component - object
- Gift of Dr. G. R. Airth
Cite this page
We encourage the use and reuse of our collection data.
Data in the title, made, maker and details fields are released under Creative Commons Zero
Descriptions and all other text content are licensed under a Creative Commons Attribution 4.0 licence
Download catalogue entry as json
Download manifest IIIF
Our records are constantly being enhanced and improved, but please note that we cannot guarantee the accuracy of any information shown on this website.