[Milsurplus] Oddball Tube: Microwave Amp?

[Raymond F Chase]

I agree with Jim and Glenn, there are two tubes inside the assembly, possibly ceramics.  Note that the heaters must be at ground potential since there is only one lead for each filament.  If the plates are grounded then the cathode is at some potential with the heater, not impossible, just another complication.  Any other clues; where did it come from, how was it obtained, any packaging?  Whatever, an interesting device, nice collectable.

Ray

 

From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Jim Whartenby
Sent: Monday, February 05, 2018 1:45 AM
To: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Oddball Tube: Microwave Amp?

 

I agree with Glenn that the tubes are either ceramic or pencil triodes but it looks to me like there are two tubes inside the cavity.  I see feed-through capacitors for two grids, two cathodes, two heaters and two tuning caps or plungers.  Didn't note any plate feed-through caps so they must be at ground potential.

 

Should be easy to ohm out the heaters to see if they are connected to one or two tubes.  Apply 6.3 volts to the heater feed-through and ground; if current is about 250 mA then the tube is likely a 7077, if current is 135 mA then it might be a 5876.  There are other similar planer triodes which may have different current demands.  GE ceramic tube data is somewhere on the 'net.

Nice find,

Jim

 

  _____  

From: Glenn Little WB4UIV <glennmaillist at bellsouth.net <mailto:glennmaillist at bellsouth.net> >
To: milsurplus at mailman.qth.net <mailto:milsurplus at mailman.qth.net>  
Sent: Sunday, February 4, 2018 9:56 PM
Subject: Re: [Milsurplus] Oddball Tube: Microwave Amp?

 

I highly suspect that this is an assembly and not a tube.
It looks like it might unscrew near the center.
If it does, I suspect that you will find a 7077 or similar tube inside.

I could be wrong and it could be a klystron or something similar.

73
Glenn
WB4UIV
On 2/4/2018 2:08 PM, David Stinson wrote:
> Here's an oddball tube.  "Input" on one end,
> "Output" on the other, with tube element
> connections between.  Anyone familiar?  Know how
> to hook it up?
>
> https://photos.app.goo.gl/9be5plc6QLWlWlps1
>
> 73 Dave AB5S
>
>
>
>
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-- 
-----------------------------------------------------------------------
Glenn Little                ARRL Technical Specialist  QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv at arrl.net <mailto:wb4uiv at arrl.net>     AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)  USSVI LM  NRA LM  SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"



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