My friend Danial Stocks provided this information about these tubes.
Double tetrode transmitting tubes. The big ones are 5984 or in the European coding QQE06/40. Note the EEV one also says C178A - EEV specific part no.. The little one QQE03/20 - may have a US no but I dont know it. These work up to around 500 MHZ or so. There are eutralizing caps built into the tube [note the little curls of wire coming off the top of the grids] so they can be run without neutralization. Supersedes the 829A and 823A respectively. Many refs to things like this in mid century amateur radio publications like Radio Comms Handbook.. |