[ARC5] Why "Noodling" About Sweep Tubes

[Ian Wilson]

"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."

Not sure about this: the 4-125A is a tetrode, and the 4E27 can manage
suppressor grid modulation, which would seem to suggest more of a
traditional g3?

73, ian K3IMW


On Tue, Oct 22, 2013 at 2:13 PM, Kenneth G. Gordon
<kgordon2006 at frontier.com> wrote:
> 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
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