My First Tube Baby-steps., Using a triode for the first time.

[JoOngle]

Today is a GOOD day,

For the first time in my LIFE, I've actually managed to use a Tube
and make it work, and understand how it works.

(Yes, I know - that's no great achievement, rather lame actually...)

But for some reason, the "tube lore" has always been hovering above me,
most of you regulars in here KNOW this, and I haven't really experimented
a lot, just tried to dabble in old books with math WAY over my understanding
so I never truly "got it" before today!

The reason? I just tried it out, found a triode, blew one up, and had success
with another.

So what did I do?

Make it amplify something, just like a transistor, I think Tim in here wrote
once, it's even simpler than transistors to use, and now I understand
what he meant - they're truly simple to use, dangerous as h... but simple.

Why can't books explain it for how simple it is? It's so simple it's sort of
stupid, while feeling great for having it worked out and having a working
example of the theory, it's so simple that a kid of 5 could do it.

And for the other people who "look forever" for the same simple information
it's darn simple:

- Connect the specified Heater voltage to the Heater pins
- Connect the high voltage to Anode and Cathode, eg. the + to the
Anode (possibly with a 10K resistor between the Anode and 200v if you
plan to draw the difference between the anode and the 200v+)
- The grid is your "B" base pin, just like the transistor, anything you
input there, will be amplified and can be drawn out between the 10K resistor
between the high voltage psu and the anode...

Why don't anyone describe it like that? it's so bloody simple! Dang...that was
what I didn't get before? (pounds head!)

I'm actually quite amazed how well they perform as well, the amplification
is by no means meager and bad.

Ok, thats it - I'm going to make my very first tube radio now, can't wait!

Man, I'm going to sleep good tonight.

[CWB]

cooolll ...
what tube were you using ?

you might try a regenerative circuit for the radio ... fairly simple , low parts count and they can be surprisingly sensitive .
you might have to use a pre-selector on the front end to improve the selectivity if you live near high powered stations .

ps ... you have to let us know the first time you get bit .

[ChipUser]

I almost read the title as "my test tube baby's first steps"

Congratulations!

[MacFromOK]

As a non-tuber, I'm impressed if no one else is Jo.

Gonna put the radio circuit in this thread or start another?

[draget]

Wouldn't it be slightly pointless to connect the valve without a load?

Now add cathode bias and some coupling caps and you have an audio signal stage

[Geek]

Congratulations!!!

You hit the key phrase with these glassfets: "it's darn simple".

Cheers!

[JoOngle]

@CWB

It was an EC92, and I've been bitten long before I even knew how it worked, you know...even
though tubes where LONG before my time, that glow was just magical to me.

@ChipUser, lol - test tube baby...

@MacFromOK, Thanks, well - It'll probably be in this thread, I'll have to experiment
a bit more, you know - get my hands dirty (hopefully not get shocked & dead)
first, then I'll do stuff - you can believe that!

@Draget, To figure out how it worked - was not really pointless in any way, for an experienced
user - yes, to me? Baby-steps.... anyhow, I'll have to go the Audio-Amp way as you
suggest, I'm reading up upon a 60 year old tube-electronics book from Denmark now, so
we'll see.

@Geek, LOL! Glassfets - perfect name.

[tekwiz]

It is a good name, as field effect transistors are the closest semiconductor to tubes. In some circuits, they can be used as a direct substitute. Tom, tubes are very simple to understand, much easier than transistors. Did you look up a basic description of how they work?


BTW: Congrats. Feels good, don't it?

[JoOngle]

Didnīt know that Tek, thanks for the heads up!

I have looked it up many times, but didnīt understand them before I tried
them in actual practical use. I was so irritated and annoyed that I didnīt get
something so supposedly simple, so what I did...was to just connect them
to their specs according to the Datasheets, and experimented with inputting
and outputting current and checked for variations, the darn books...just
showed a LOT of fairly complex math formulas that I didnīt get (sorry - Iīm
no math genious)

I think Iīve told that numerous times - the no #1 reason for me having
so many test-instruments is that they have always thaught me what happens
INSIDE each component, and circuit - thats how I was capable of building
a FM radio from scratch without schematics, thats how I built and programmed
a robot from scratch... I *must* learn from doing, I can understand theory
on a platonic level, but I have this thing that "prohibit" me from learning
if I donīt understand EXACTLY whatīs going on...

...I canīt just "grasp huge math theories" and understand how to build
a circuit out of that just like some of those with YEARS in schools can...
for students - this is hard to understand - that I canīt just like they can...

...even more baffling for them...when I understand it in "practice".

I credit the "instruments" for that knowledge. If you catch my drift?

And yes - if feels GREAT!

[tekwiz]

No math needed to understand tubes; triodes at least. The heater boils electrons from the cathode, which are attracted to the positive plate, unless repelled by the grid. It's that simple.

[Sch3mat1c]

Huge equations? I challenge you to find anything with more than three terms and five variables in RC-26 or so (RCA Recieving Tube Manual). The most important are equivalent to Ohm's law.

Sounds to me it's time to turn your fear of math into an integrated part of your understanding of the world.

Tim

[mravenca]

I think that there is nothing much difficult in understanding a tube linear model, it's similar to transistors.. (h and y parameters,..)

[mravenca]

Anyway, my father told me once that they used tu use a huge rf power tube as a lamp in his room in dormitory, during his studies

[Sch3mat1c]

A rather inefficient way (thoriated tungsten filaments operate about 2/3 the temperature of an incandescent bulb), but very nice for ambiance.

Tim

[CWB]

yessir ... "mood lighting" and semantics .

that would really impress some woman you invited over .

[tekwiz]

Not to mention that "feeling of warmth" that comes from a >500W cathode heater.