The Hantek 6022BE seems to be a very cheap and popular OSC.

http://www.banggood.com/Hantek-6022...-Storag-Oscilloscope-2-Channels-p-925842.html

It says 20MHz Bandwidth in the datasheet. Does this mean I cannot measure FM frequencies of around 100 MHz when I want to built an FM transmitter circuit for example?

 

yes.

 

yes.

What kind of bandwidth does the OSC need to be able to measure FM frequencies?

One the box of the Hantek it says Bandwidth 20Mhz/60/100/200MHz. What does this mean then?

Have a look

 

I have an old Tektronix 2465A DM for RF needs.
http://www1.tek.com/forum/viewtopic.php?f=5&t=19

 

I have a old Tektronix 2465A for RF needs.
http://www1.tek.com/forum/viewtopic.php?f=5&t=19

I'm only interested in the Hantek model as it costs only around $65 USD, which is the most I could ever spend on an OSC. So it's either that one or none

 

What kind of bandwidth does the OSC need to be able to measure FM frequencies?

One the box of the Hantek it says Bandwidth 20Mhz/60/100/200MHz. What does this mean then?

Have a look

It only measures 20 Mhz, as it says on the webpage. I own two Hanteks, and the box is just a generic one in which they check the appropriate selection box with a marker indicating which model is inside. Since this model is none of those listed at the top of the box, they have placed an extra label on the side detailing its contents.

 

I'm only interested in the Hantek model as it costs only around $65 USD, which is the most I could ever spend on an OSC. So it's either that one or none

100mhz of real bandwidth is not cheap. You usually get what you pay for.

 

The scope you posted was rated for 20 mhz and I would stay below that .. Otherwise I would suggest buying a used analog scope for about the same price and it's a lot better IMO...

 

Using rating 20Mhz to measure 100Mhz waveform, you may just see the appearance of the waveform, if you just want to know the frequency then you can adding a TC74AC390 that it could reach up to 160Mhz, you could divide the input frequency by TC74AC390 and then you can measuring the input frequency over 100Mhz.

 

What kind of bandwidth does the OSC need to be able to measure FM frequencies?

It depends what you want to observe --- analysis of harmonic distortion will require several octaves (over the fundamental) of flat response... Note, however, that it is less than practical to observe the carrier with a TDO --- Spectral profile is far better observed with a frequency domain oscilloscope (a.k.a. spectrum analyzer) -- On the other hand many common communications systems parameters (e.g. deviation, IMD, CMD, etc...) may be assessed via 'detection' techniques and, hence, modest bandwidth (where a TDO is applicable)...

Best regards
HP

 

The Hantek 6022BE seems to be a very cheap and popular OSC.

http://www.banggood.com/Hantek-6022...-Storag-Oscilloscope-2-Channels-p-925842.html

It says 20MHz Bandwidth in the datasheet. Does this mean I cannot measure FM frequencies of around 100 MHz when I want to built an FM transmitter circuit for example?

YES it means it will not measure any frequencies more than 20MHz

However the numbers do refer to higher sampling rates which improves performance. But are still limited to the signal filter response of 20 MHz

Since FM is from 88 to 108MHz you need at least 100MHz BW to even consider looking at the waveform but it wont see harmonic distortion.

 

A good bid on this would be very useful for RF work

http://www.ebay.ca/itm/HP-8593E-mic...407?pt=LH_DefaultDomain_0&hash=item4ae7fc9687

but you probably cant afford the shipping cost... $500

9kHz ~ 20GHz

 

Do you need to SEE the signal or just measure it? how 'bout a frequency counter? Cheap on ebay.
http://www.ebay.com/itm/1MHz-1GHz-R...065?pt=LH_DefaultDomain_0&hash=item5d54491c61

 

YES it means it will not measure any frequencies more than 20MHz

And that spec is for a sine wave. Viewing a reasonable approximation of a 20MHz square wave would require at least 3X that bandwidth.

For a couple hundred dollars, you could probably pick up a Tek 1GHz analog scope (used and 30 years old, of course!). Or you could go with a more affordable 7704A (200MHz) with appropriate plug ins. But you need a lot of bench space or a scope cart...

 

- transmitters demand a spectrum analyzer for complex measurements.. compression intercept, THD, deviation ratio , pilot tone spectra. adjacent channel interference, frequency stability and f measurements with a harmonic marker, etc
- baseband requires a scope.

 

- transmitters demand a spectrum analyzer for complex measurements.. compression intercept, THD, deviation ratio , pilot tone spectra. adjacent channel interference, frequency stability and f measurements with a harmonic marker, etc
- baseband requires a scope.

I wish to add my voice to TonyStewart's (post #15) --- Quality work (be it engineering or technical) requires proper equipment! 'Workarounds' amount to little more than rationalized guesswork -- Parsimony has no place in the lab or shop!!!

Best regards
HP

 

A good bid on this would be very useful for RF work

http://www.ebay.ca/itm/HP-8593E-mic...407?pt=LH_DefaultDomain_0&hash=item4ae7fc9687

but you probably cant afford the shipping cost... $500

9kHz ~ 20GHz

Sweet!!!

 

Thank you all for the comments. Very helpful.

I suppose as a start, I just need to be able to see if the FM transmitter is working and what frequency it is transmitting at (95.6MHz, 101Mhz, etc.) so I know what frequency to tune in on a radio. If the 20Mhz the Hantek offers are not enough than I have to search locally for a used analog OSC with at least 100 MHz bandwidth or higher.

 

In some videos I have seen some people use a small handheld device with a simple LCD screen and it was able to show the frequency number value in MHz by simply holding the device close to the RF transmitter.

What kind of device is that and would it replace the need for a scope for this kind of purpose?

So far I was able to build most circuits without having a scope. I only have a few multimeters and they served well for most needs so far. I like building analog circuits, but other than RF stuff I haven't seen the urgent need for a scope. Other than RF frequency testing, what do you use your scope for usually?

I think eventually I will see myself using mostly micro controllers such as the ATMEGA, ATTINY or the new ESP8266. It just allows you to make more complex stuff on a smaller scale than using pure analog circuit design and ICs. In that case is a scope still something that would be useful and frequently used?

 

using an osciliscope to measure freuency isnt a good idea, get a counter, more accuracy, and resolution, as well as cheaper. there are frequency converters for osciliscopes that mix the observed signal with an oscilator to get it down to the bandwidth of the scope. the freque3ncy resolution of measuring a scope without built in counter isnt good enough for more than a guess.