Add group to favorites
Back to post list
Send new message to group Search:
Post Subject:
doorknob UHF triodes
doorknob UHF triodes
After reading up about tubes like the 316A or 368A they leave me with a
few questions. Why are the filaments at such a low voltage with such a
high current? 1.15v at 4.5 amps is pretty odd. A few tenths of an ohm
contact resistance would really effect emission. The plate structures
inside look very small for their rated dissipation. The 368A plate looks
like 3 small fins radiating outward, really not much bigger than a 12AU7
plate. Its rated for 20 watts but does not say if thats continuous or
pulse operation. Does that sound right to anyone?
Adam
After reading up about tubes like the 316A or 368A they leave me with a
few questions. Why are the filaments at such a low voltage with such a
high current? 1.15v at 4.5 amps is pretty odd. A few tenths of an ohm
contact resistance would really effect emission. The plate structures
inside look very small for their rated dissipation. The 368A plate looks
like 3 small fins radiating outward, really not much bigger than a 12AU7
plate. Its rated for 20 watts but does not say if thats continuous or
pulse operation. Does that sound right to anyone?
Adam
Re: doorknob UHF triodes
Adam Stouffer wrote:
> After reading up about tubes like the 316A or 368A they leave me with a
> few questions. Why are the filaments at such a low voltage with such a
> high current? 1.15v at 4.5 amps is pretty odd.
Since they have directly heated cathodes, any higher filament voltage would
'skew' the chacteristics since the cathode-grid field would vary
significantly from one end of the cathose to the other.
Graham
Adam Stouffer wrote:
> After reading up about tubes like the 316A or 368A they leave me with a
> few questions. Why are the filaments at such a low voltage with such a
> high current? 1.15v at 4.5 amps is pretty odd.
Since they have directly heated cathodes, any higher filament voltage would
'skew' the chacteristics since the cathode-grid field would vary
significantly from one end of the cathose to the other.
Graham
