# Cheap good ways to measure into the high mHz to low ghz range?

#### jarwulf

Joined Jul 7, 2013
60
Hi I'd like to measure waveforms ranging from the low ghz to mhz range. Unfortunately almost all the oscilloscopes I've looked at seem to only go up to 50mHz to 100mHz before becoming prohibitively expensive. At least I'd like something that could go up to around 200mHz. Would a chinese USB scope like this

http://www.ebay.com/itm/HDSO-100-50M-Dual-Channel-USB-Oscilloscope-100M-Sampling-Rate-Digital-Virtual-/121715020637?hash=item1c56c7d35d:g:0RcAAOxycmBSp~13

be a good deal?

It claims to have a bandwidth of 100MHz - 349MHz. Does that mean it can't measure below 100mhZ?

Should I get a spectrum analyzer instead to measure into that range? Even though those seem even more expensive. Is their any other alternative type of instrument that I could substitute?

#### bertus

Joined Apr 5, 2008
20,567
Hello,

If you are not interested in the shape of the signal, but only its frequency, you could have a look at a frequency counter.

Bertus

#### Papabravo

Joined Feb 24, 2006
13,924
You just don't understand the complexity of measuring anything at those frequencies. To be a lone RF Engineer requires equipment more valuable than most people's houses. Short of winning the lottery, you might have some luck on eBay or one of the rental companies. Most of the stuff coming off rental is in pretty tough shape however. At those kinds of prices it is easy to get taken as well. Last option is to cultivate an FAE who might tip you off to somebody getting rid of a piece of equipment on the cheap.

#### Hypatia's Protege

Joined Mar 1, 2015
3,223
Unfortunately almost all the oscilloscopes I've looked at seem to only go up to 50mHz to 100mHz before becoming prohibitively expensive. At least I'd like something that could go up to around 200mHz. Would a chinese USB scope like this
If you don't require storage, new/NOS readout CRO's having half-power bandwidths of 500MHz are available for ≤ $8k --- they'll last a lifetime in skilled hands! Best regards and good luck HP #### kubeek Joined Sep 20, 2005 5,724 Not many people come to terms with extremely low frequencies, are you really sure you are talking about milli Hertz (mHz) and not about Mega Hertz (MHz)? #### Hypatia's Protege Joined Mar 1, 2015 3,223 As an aside -- unless you are analyzing transients, waveform characteristics (i.e. harmonic content, etc...) at VHF and above are better (and more economically) examined via an SA (AKA -- at risk of appearing pedantic --a frequency domain oscilloscope)... Best regards HP #### Aleph(0) Joined Mar 14, 2015 597 If you don't require storage, new/NOS readout CRO's having half-power bandwidths of 500MHz are available for ≤$8k --- they'll last a lifetime in skilled hands!

Best regards and good luck
HP
HP Is $8,000 cheap? #### Aleph(0) Joined Mar 14, 2015 597 As an aside -- unless you are analyzing transients, waveform characteristics (i.e. harmonic content, etc...) at VHF and above are better (and more economically) examined via an SA (AKA -- at risk of appearing pedantic --a frequency domain oscilloscope)... Best regards HP HP If you are meaning rise and fall times when you say transients I say spectrum analyzer ok for that too! Is less intuitive for that purpose but you can save a lot of money Last edited: #### Papabravo Joined Feb 24, 2006 13,924 Not many people come to terms with extremely low frequencies, are you really sure you are talking about milli Hertz (mHz) and not about Mega Hertz (MHz)? If he was talking about low frequencies the terms would be millihertz, microhertz, nanohetrz, and picohertz. I think the OP/TS like many text speakers can't be bothered to use the shift key. I guess we won't be getting to Mars anytime soon. #### Papabravo Joined Feb 24, 2006 13,924 HP Is$8,000 cheap?
To an RF Engineer it is peanuts. To the rest of us maybe not so cheap.

#### Hypatia's Protege

Joined Mar 1, 2015
3,223
HP Is $8,000 cheap? For 500MHz bandwidth!? -- Dirt cheap! I respectfully submit that "expensive vs. inexpensive" is relative to the product -- not the parsimony of the purchaser! --- Should one fail to regard proper instruments as worth their FMV then their 'heart' is not in their work/avocation -- my$.02

Best regards
HP

#### spinnaker

Joined Oct 29, 2009
7,835
To an RF Engineer it is peanuts. To the rest of us maybe not so cheap.
For 500MHz bandwidth!? -- Dirt cheap!

Best regards
HP