![](https://coimages.sciencemuseumgroup.org.uk/50/675/large_thumbnail_1972_0141_0248__0002_.jpg)
Wade Bequest collection of valves: Catkin triode radio valve, by Marconi-Osram
- PART OF:
- Wade Bequest collection of valves
- Made:
- England, Germany and United States
![SMG00237615](https://coimages.sciencemuseumgroup.org.uk/448/576/medium_smg00237615.jpg)
Wade Bequest collection of valves: Catkin indirectly-heated triode radio valve, by Marconi-Osram. With B5 base and external copper anode. Paper label: W57.