[ARC5] Why "Noodling" About Sweep Tubes

[Kenneth G. Gordon]

Bill is certainly right about the 4E27 and the 4-125 and its pulse variants. I 
had forgotten about those. Either would be perfect for your uses, and both 
are cheap on eBay, especially the pulse variants which are not as easily 
recognized.

There was a later variant of the 4E27: the 5-125B/4E27A. Those often show 
up too, but sell for higher prices.

The PD of the 4E27 is 75 watts, while that of the 4E27A is 125 watts.


Either one uses an 813 socket.

Although they are "beam tubes" their advantage over other types of beam 
tubes is that their beam-forming plates are connected to separate pins, and 
not to the cathode, as all octal-based beam-tubes are.

Ken W7EKB