[Milsurplus] crystal currant

[phil]

Depending upon circuit, crystal currant is generally less in a tetrode or
pentode oscillator, because of the lower grid-plate capacity. Some
pentodes have a grid-plate cap of only 0.01 p  while triodes have a
range of about 5p to 10p depending.

Some tetrodes or pentodes need an external cap between the grid
and plate to get then to oscillate.

pentodes with low cap are the 802 and 837
The 807 has a higher cap of 0.2p
Phil