Triode connected pentode.

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pre65
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#1 Triode connected pentode.

Post by pre65 »

If the data sheet for a pentode connected as a triode (typical characteristics) specifies grid 3 as 0v, does that mean no connection ?
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Cressy Snr
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#2 Re: Triode connected pentode.

Post by Cressy Snr »

pre65 wrote:If the data sheet for a pentode connected as a triode (typical characteristics) specifies grid 3 as 0v, does that mean no connection ?
Nope it means grid 3 is either:

a) grounded independently
b) grounded via its (if fitted) internal connection to a grounded cathode.
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pre65
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#3 Re: Triode connected pentode.

Post by pre65 »

SteveTheShadow wrote:
pre65 wrote:If the data sheet for a pentode connected as a triode (typical characteristics) specifies grid 3 as 0v, does that mean no connection ?
Nope it means grid 3 is either:

a) grounded
b) is internally connected to the cathode (as most are) and the cathode is grounded.
In that case it must be grounded, I should have realised that. Doh. :oops:

Thanks Steve. :)
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Paul Barker
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#4

Post by Paul Barker »

If it is not internally connected to cathode as in case of EL34 and 813 to name a few you can connect it to anode with g2 via 100ohm resistor which will be marginally different performance.
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Mike H
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#5

Post by Mike H »

Typically on a datasheet cathode is at 0V, so then g3 is connected to 0V. But as said with internally connected designs you don't get a choice.

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Nick
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#6

Post by Nick »

Mike H wrote:Typically on a datasheet cathode is at 0V, so then g3 is connected to 0V. But as said with internally connected designs you don't get a choice.

HTH
I would beware that you are not reading too much into that. By definition in most data sheets the cathode is 0v, so g3 at 0v just means its connected to the cathode.
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