Help to decide which Oscilloscope to buy.

[Adam24]

Hello ,
i need help regarding an older Oscilloscope , it's the BK 2522
WHich is 20MHz Oscilloscope.
Is this a good choice for making Metal detectors ?
It's available for a good

[moodz]

If it fits your budget its fine. Plenty of detectors were designed with no scope at all :-)

The older tube scopes have certain advantages over newer digital scopes
- you will spend less time down the rabbit hole LOL. Ferinstance you will spend less time chasing noise glitches that plague high bandwidth sampling digital scopes.

[profesor]

I have had many oscilloscopes. Have I found what I want yet? I don't know. But oscilloscopes should be divided into three groups.

1-analog oscilloscopes.

2-digital oscilloscopes.

3-analog-digital (conbiscope) oscilloscopes.

If you are examining signals in depth, none of them can catch up with analog oscilloscopes in terms of screen refresh rate. Moreover, if it has an MCP tube, it will be a very superior device. The negative aspects of this technology are its large size, if it is an ordinary oscilloscope; there will be no frequency measurement. In fact, you can hardly measure it. But I think combiscopes, which have many measurement functions in addition to their analog structure, would be a good choice.

Simple digital oscilloscopes are cheap. However, they are behind in terms of measurement accuracy and reliability. In addition, since their screen refresh rate is slow, it causes errors in detectors.
Recently, quality brands seem to have solved this problem to a great extent. If you have the money to buy a quality oscilloscope, it is time for a digital oscilloscope.

[Adam24]

I have had many oscilloscopes. Have I found what I want yet? I don't know. But oscilloscopes should be divided into three groups.

1-analog oscilloscopes.

2-digital oscilloscopes.

3-analog-digital (conbiscope) oscilloscopes.

If you are examining signals in depth, none of them can catch up with analog oscilloscopes in terms of screen refresh rate. Moreover, if it has an MCP tube, it will be a very superior device. The negative aspects of this technology are its large size, if it is an ordinary oscilloscope; there will be no frequency measurement. In fact, you can hardly measure it. But I think combiscopes, which have many measurement functions in addition to their analog structure, would be a good choice.

Simple digital oscilloscopes are cheap. However, they are behind in terms of measurement accuracy and reliability. In addition, since their screen refresh rate is slow, it causes errors in detectors.
Recently, quality brands seem to have solved this problem to a great extent. If you have the money to buy a quality oscilloscope, it is time for a digital oscilloscope.

Thank you for the advice
I will let you know which brand and model i will buy ,there is few analog Oscilloscopes within sight,older ones but as the seller states are in good used condition.

[Adam24]

If it fits your budget its fine. Plenty of detectors were designed with no scope at all :-)

The older tube scopes have certain advantages over newer digital scopes
- you will spend less time down the rabbit hole LOL. Ferinstance you will spend less time chasing noise glitches that plague high bandwidth sampling digital scopes.

Thank you Moodz.
So the one i pictured is good to buy,also do this type have multimeter functions such as voltage,amps ,ohms etc

[bbsailor]

Hello ,
i need help regarding an older Oscilloscope , it's the BK 2522
WHich is 20MHz Oscilloscope.
Is this a good choice for making Metal detectors ?
It's available for a good

When you use an oscilloscope and a signal generator to measure the coil resonant frequency, you need to do this.
1. Add a 1 Meg ohm resistor in series between the signal generator and the coil to reduce loading on the coil and to see the coil resonance more clearly as well as next.
2. Add a 1 pf capacitor in series with the coil and the oscilloscope to also minimize coil loading.

Once you know the coil resonant frequency, very easily seen by doing 1 and 2 above, as well as the coil inductance, you can then calculate the coil seen capacitance from
1. Coil wire turn to turn phantom capacitance driven by wire insulation thickness and insulation type with Teflon being the lowest.
2. Coil to shield capacitance based on the area of the shield around the coil wire bundle.

These are just points to consider when planning to make a fast mono coil and using test equipment.

Joseph J. Rogowski

[ZuMi77]

This instrument doesn't display the frequency value directly. You have to calculate it manually using the formula: f=1/T (T is the signal period). Usually I need to tune the oscillator or LC circuit to a specific frequency (or two LC circuits at the same time); if the oscilloscope doesn't display the frequency value directly, the process will not be straightforward. As far as I know, the best brands are: Rigol, Hantek, Tektronix & Siegel.

[ivconic]

I have a 2x20MHz analog oscilloscope, almost new, bought in 2020 as new.
It is completely sufficient for amateur works.
But 20 days ago I saw something interesting.
A friend, a hobbyist, from another place, bought a small, very cheap oscilloscope through "Temu".
He asked me if he could come to me to show him how to do the correct damping on the PI coil.
I agreed out of politeness, but when I saw the picture of the oscilloscope he bought, I thought: "No way with that..."
To my surprise, that little oscilloscope did the job well.
It doesn't have that display like analog, it doesn't have that detail, but it's good enough for the money it's paid for.
But what I particularly like is the complete printout of all parameters on the display (it can be adjusted in the menu).
It literally has all the parameters expressed in numbers.
(I hate math and subsequent calculations... especially for quick measurements and routine jobs)
It even has some parameters that I don't even know what they are!
Unerringly accurate measurements of frequency, amplitude, etc. And it prints everything very legibly on that small display.
Just what I'm missing from my otherwise good analog oscilloscope.
It has a built-in Lipo battery, a USB port for charging and updating.
2 channels, 2 really good probes.
It is slightly larger than a standard pack of cigarettes.
I had a couple of DSO oscilloscopes until now, sooner or later I would have sold them because I was not satisfied.
But I really liked this one and decided to buy it soon.
To be understood; it cannot replace a good analog or digital oscilloscope.
But it can get most of the work done and still be carried in your pocket and used outside the workshop.
Link: https://www.temu.com/rs-en/handheld-...427_t1cagpc3ih

[Eddy71]

My relative bought such an oscilloscope to monitor the signal not only on the desktop, but also in nature, where there is no interference from industrial sources.
He is very satisfied.
https://vi.aliexpress.com/item/1005007928485656.html

[Adam24]

I have had many oscilloscopes. Have I found what I want yet? I don't know. But oscilloscopes should be divided into three groups.

1-analog oscilloscopes.

2-digital oscilloscopes.

3-analog-digital (conbiscope) oscilloscopes.

If you are examining signals in depth, none of them can catch up with analog oscilloscopes in terms of screen refresh rate. Moreover, if it has an MCP tube, it will be a very superior device. The negative aspects of this technology are its large size, if it is an ordinary oscilloscope; there will be no frequency measurement. In fact, you can hardly measure it. But I think combiscopes, which have many measurement functions in addition to their analog structure, would be a good choice.

Simple digital oscilloscopes are cheap. However, they are behind in terms of measurement accuracy and reliability. In addition, since their screen refresh rate is slow, it causes errors in detectors.
Recently, quality brands seem to have solved this problem to a great extent. If you have the money to buy a quality oscilloscope, it is time for a digital oscilloscope.

Ok you said the analog Oscilloscopes are great but you also said you can't measure frequency in depths what is this mean .thank you

[Adam24]

I have a 2x20MHz analog oscilloscope, almost new, bought in 2020 as new.
It is completely sufficient for amateur works.
But 20 days ago I saw something interesting.
A friend, a hobbyist, from another place, bought a small, very cheap oscilloscope through "Temu".
He asked me if he could come to me to show him how to do the correct damping on the PI coil.
I agreed out of politeness, but when I saw the picture of the oscilloscope he bought, I thought: "No way with that..."
To my surprise, that little oscilloscope did the job well.
It doesn't have that display like analog, it doesn't have that detail, but it's good enough for the money it's paid for.
But what I particularly like is the complete printout of all parameters on the display (it can be adjusted in the menu).
It literally has all the parameters expressed in numbers.
(I hate math and subsequent calculations... especially for quick measurements and routine jobs)
It even has some parameters that I don't even know what they are!
Unerringly accurate measurements of frequency, amplitude, etc. And it prints everything very legibly on that small display.
Just what I'm missing from my otherwise good analog oscilloscope.
It has a built-in Lipo battery, a USB port for charging and updating.
2 channels, 2 really good probes.
It is slightly larger than a standard pack of cigarettes.
I had a couple of DSO oscilloscopes until now, sooner or later I would have sold them because I was not satisfied.
But I really liked this one and decided to buy it soon.
To be understood; it cannot replace a good analog or digital oscilloscope.
But it can get most of the work done and still be carried in your pocket and used outside the workshop.
Link: https://www.temu.com/rs-en/handheld-...427_t1cagpc3ih

Thank you very much..but if i go with big older analog Oscilloscopes is this ok

[ivconic]

It's absolutely ok.
The oscilloscope from the picture in post #1 seems more than good for that purpose.
But remember; detectors are not made by an oscilloscope but by man.
An oscilloscope is just an instrument that serves a purpose.
In the 90's I successfully built detectors even in periods when I didn't have an oscilloscope... or I had some old single channel with tubes!
If you need an oscilloscope for balancing coils; an ordinary voltmeter in the range of 20-200mV can also serve.
Not even a voltmeter is necessary.
On the front page of the forum Carl provided a "Projects" section and in that list you also have "Magnum" by Andy Flind, a pdf document:
https://www.geotech1.com/cgi-bin/pag...gnum/index.dat
In which on one of the pages you have solution on how to make a "instrument" for balancing coils from a simple material.
You need a "VU" moving scale, one diode and a couple of simple components.
It is possible to make a detector only with the help of good intuition, coils can be successfully balanced with the help of several types of "targets", among them a piece of ferrite, a piece of iron and a couple of coins, and it is preferable to have a piece of ancient ceramics.
If you look back on the forum some old threads (TGSL for example); you can find many ways in which various enthusiasts have come up with their work.
Of course; it is good to have an oscilloscope. But it is not crucial. A solid DIY detector can be made without it.

[Adam24]

It's absolutely ok.
The oscilloscope from the picture in post #1 seems more than good for that purpose.
But remember; detectors are not made by an oscilloscope but by man.
An oscilloscope is just an instrument that serves a purpose.
In the 90's I successfully built detectors even in periods when I didn't have an oscilloscope... or I had some old single channel with tubes!
If you need an oscilloscope for balancing coils; an ordinary voltmeter in the range of 20-200mV can also serve.
Not even a voltmeter is necessary.
On the front page of the forum Carl provided a "Projects" section and in that list you also have "Magnum" by Andy Flind, a pdf document:
https://www.geotech1.com/cgi-bin/pag...gnum/index.dat
In which on one of the pages you have solution on how to make a "instrument" for balancing coils from a simple material.
You need a "VU" moving scale, one diode and a couple of simple components.
It is possible to make a detector only with the help of good intuition, coils can be successfully balanced with the help of several types of "targets", among them a piece of ferrite, a piece of iron and a couple of coins, and it is preferable to have a piece of ancient ceramics.
If you look back on the forum some old threads (TGSL for example); you can find many ways in which various enthusiasts have come up with their work.
Of course; it is good to have an oscilloscope. But it is not crucial. A solid DIY detector can be made without it.

Thanks a lot

[Nightryder]

When I bought mine, I didn't consider the math function which seems (some if not most) oscopes have. I regret it because it makes your work a lot more easier. So, you might want to consider it. For building detectors, your oscope has to be at least two channels. Some oscopes use a 5 volts adapter with a USB cable for power meaning that you can also power it from any 5V power bank. This can protect your oscope from getting fried.

Those are the highlights which I could think of, Good Luck!