[AMRadio] Clear 866A

Rob Atkinson ranchorobbo at gmail.com
Tue Oct 4 21:37:58 EDT 2016

Early 866As from my observations were loaded with mercury but later
ones, made in the 1970s for example didn't have much that can be seen
by looking.  My hunch is that at some point, someone figured out it
doesn't take much and the amount going in went way down.  they'll
probably work fine and in fact, may be less likely to flash over.  I
have old RCAs that you can see the mercury in, and 1970s 866As that
look devoid of mercury.


On Tue, Oct 4, 2016 at 8:25 PM, Mark Foltarz via AMRadio
<amradio at mailman.qth.net> wrote:
> I came across a box of tubes labeled 866A.The odd thing about them is there absolutely no mercury and no gettering - although there is clearly a getter mounted to one of the filament leads.Has anyone ever seen an 866A like described above ? I haven't tried these in any of my transmitters yet.

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