Making a decent oscilloscope from a TV?

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▶Making a decent oscilloscope from a TV? Anonymous 04/10/19 (Wed) 15:43:08 No.1050905 [Watch Thread][Show All Posts]

Where I live oscilloscope are very expensive, think 300 or 400 dollars for the shittiest 20mhz used one.

The reason the common conversion of a TV into an oscilloscope doesn't really work beyond audio frequencies is that the RF signals are blocked by the inductance of the coils that are used to control the electron beam.

So could a TV CRT beam be deflected electrostatically by placing high voltage electrodes OUTSIDE the tube? Maybe a little bit of tinfoil glued to the neck of the CRT? (since the glasswork and vacuum pump work to get electrodes inside the tube would be impractical to do)

▶Anonymous 04/10/19 (Wed) 19:38:30 No.1050954>>1050989

File (hide): 51f309715fe0c71⋯.jpg (182.33 KB, 1280x960, 4:3, Tektronix_1720_vectorscope.jpg) (h) (u)

>So could a TV CRT beam be deflected electrostatically by placing high voltage electrodes OUTSIDE the tube?

Not with standard TV CRT. Pic related is what is used in oscilloscopes using electrostatic deflection. Note the length of the tube, which is needed to get reasonable deflection from such system. Just buy a Hantek from ebay for 60$. TV scope is an useless toy. You would also need a triggering circuit, ramp generator, amplifier various additional power supplies and a ton of other supporting circuits to make this scope somewhat useful.

▶Anonymous 04/10/19 (Wed) 20:18:20 No.1050958>>1050989

You can get you a 100MHz digital scope for about $300.

▶Anonymous 04/10/19 (Wed) 21:47:25 No.1050989>>1050995 >>1051027

>>1050954

>>1050958

The shipping costs kill me (like 200 usd average) and my country is so cucked I would need to hire a person with a special 4 year degree just to do the paperwork, which would probably cost me out the ass. They just won't allow any regular person to import shit by themselves.

>>1050954

Yeah but I've heard regular oscilloscopes use 200 to 300 volts for the deflection plates so guess if my idea worked at all I would need to use like 2000v to get a big enough image.

▶Anonymous 04/10/19 (Wed) 21:53:56 No.1050995>>1051036

>>1050989

I mean the shipping costs are for the used bulky ones, new USB ones I can bring by myself without hiring anyone if they are < 100 usd as long as I pay the %60 tax, but importing shit is still a pain in the ass and for that price I could only get 20mhz bandwidth which I guess wouldn't be a problem with an analog scope.

▶Anonymous 04/10/19 (Wed) 23:01:48 No.1051027>>1051029

>>1050989

>4 year degree to do paperwork for shipping and customs

What?

▶Anonymous 04/10/19 (Wed) 23:06:40 No.1051029>>1051038

>>1051027

Yeah, you need somebody with a special license to get the government to allow you to import things into the country that cost more than 100 dollars (or for commercial use whatever the cost). And that license takes years of studying to get. I live in South America/Uruguay.

▶Anonymous 04/11/19 (Thu) 00:02:04 No.1051036>>1051040

>>1050995

Yeah, do get a digital one. Or, have it shipped to a logistics company in Buenos Aires and go collect it yourself when it's delivered, depending on how strict the Uruguayan border checks are on incoming vehicles.

▶Anonymous 04/11/19 (Thu) 00:03:45 No.1051038>>1051040

>>1051029

Can you get stuff mailed from ebay? There are a bunch of cheap shitty oscilloscopes there that I'm sure the chinks would love to ship to you.

▶Anonymous 04/11/19 (Thu) 00:16:43 No.1051040>>1051041

>>1051036

I've heard argentinian customs laws are about just as strict.

>>1051038

They'll seize anything that looks like it could be expensive and ask for the tax/bureaucracy I mentioned.

▶Anonymous 04/11/19 (Thu) 00:33:36 No.1051041>>1051043

File (hide): 5a6b466263dbe2d⋯.webm (349.45 KB, 368x368, 1:1, urgay.webm) (h) (u) [play once] [loop]

>>1051040

You could try a more lawless country like Paraguay. Then you have the problem of currency though.

▶Anonymous 04/11/19 (Thu) 00:37:15 No.1051043>>1051045

>>1051041

They don't share a border, he'd have to go through Brazil or Argentina

▶Anonymous 04/11/19 (Thu) 00:44:07 No.1051045

>>1051043

Mercosur countries have a deal like EU's schengen so he can just cross the borders with little hassle (as long as he doesn't carry suspicious shit).

▶Anonymous 04/11/19 (Thu) 04:36:44 No.1051078

>Uruguay

Ur a gay

▶Anonymous 04/11/19 (Thu) 04:42:35 No.1051081

I am a citizen of Urmomaguay. Therefore, Ur mom a gay

▶Anonymous 04/11/19 (Thu) 12:31:03 No.1051147>>1051151

File (hide): dd21ffcc1656cf8⋯.jpg (255.07 KB, 1024x843, 1024:843, 6529838985_614e303744_b.jpg) (h) (u)

I made a kit one when I was a Highly Gifted Teenager who solved all problems by himself.

The companies involved are long-gone, but this was a Dick Smith Electronics Kit K-3060.

It simply generated a vertical line on the screen, shifting it left or right on the signal amplitude. Okay for Audio-- I mostly used it with 555-based circuits. Was funky.

My excuse was being a nerd being raised by a single mother who blew all the money on cigarettes. (My first breadboard circuits were made screwing wires into pieces of wood with components pulled from dumped TV sets..)

Good luck on being more capable and resourceful than your wealthy peers, OP.

▶Anonymous 04/11/19 (Thu) 12:39:00 No.1051151

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