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Re: Tube Coils
Hi Phil,
If I read your email correctly you want some general info on how tubes work.
Let me give it a shot:
A simple triode consists of 4 main parts (not counting glass envelope, etc)
a.) The anode (plate)
b.) The grid
c.) The catode
d.) The heater filament
The glass envelope is evacuated (as the name implies). The cathode is on one
end and the plate (anode) is one the other end of the envelope. In between
these two parts sits the grid. This means electrons canīt flow freely from the
cathode to the plate. Most tubes have the heater and the cathode connected
internally. The heater is brought to dull read glow (indirect heating). This
allows electron emission. However the electrons donīt have enough speed to
reach the plate. If a positive voltage is applied to the grid (in relationship
to the cathode), the electrons are actually absorbed by the grid letting no
current flow from cathode to plate. If the grid has no charge at all (0v) then
a few electrons will eventually get to the plate (very, very small current
flow). Now, if you place a negative charge to the grid the electrons are
actually accelerated and a large amount of current can flow between the
cathode and the plate (simple amplifier). By regulating the grid voltage (via
a feedback coil) you can continuesly vary the amplification factor and
control your TC this way. Imagine a tube as a high voltage transistor. The
only real functional difference (making it easier) between a tube and
transistor is that there are no PNP or NPN tubes. All tubes have the same
current direction.
Tube greetz from germany,
Reinhard
Original Poster: Phililp Mac Duffie <shadow42-at-totcon-dot-com>
Hello, My name is Philip, I hve just started this great hobby for those who
dont know me. I have resently become interested in tube coils. I have asked
this on the tesa-2 list and was refered here by some list members. I was
talking to Mike Hammer about this stuff and he didnt seem to want to explain
any tube stuff at all, so today I went out and bought a tube. I got a 6164
tube and was hoping to use it on the coil shown on www.pupam-dot-com I really
know nothing about tubes at present so if anyone wants to help me ide
appriceate it.
Thank you,
Philip Mac Duffie
http://hv.hypermart-dot-net
P.S i allso got a 801A tube from school, would this be better?