Testing my Scope

169

00:57:48

I got myself a Voltcraft DSO-1062D quite some time ago, when I didn't use to do any RF stuff. It is sold with 60MHz bandwidth and 1Gs/s.
So some time ago I found out that you can "unlock" the software of this scope to have a bandwidth of 200MHz. The tutorial said that the hardware for this would already be in the scope...
On my last post I already stated that I was having some issues with what I measured and @hurz said, that it's rather unlikely that they would just lock the scope in software.

Since I wanted to have one of those for some time already, I got myself a ADF4351 PLL evaluation board. This let's me perform sweeps from 37MHz to 4400MHz.

I connected it to my scope with just a 50 ohm coax which has BNC on one and SMA on the other side. First I tried it with a T-piece and 50 ohm termination since my scope just has 1Mohm input, but that just led to a weird attenuation effect over some frequencies so I just took it out again. 

I get a pretty stable 1.4V p-p at everything below 200MHz which is pretty much in spec of the ADF IC. 

So I set up a sweep from 40MHz to 400MHz and looked at everything on the FFT monitor. The center axis is at 250MHz and vertical scale is 10dB per division. I took a photo with my phone, but set the shutter time to 1:30 min so it would actually draw me a curve.

I think the result does actually look pretty promising.

http://imgur.com/a/mh2FqcP

But let me know if you see any issues or have doubts.

published 6 years ago

hurz

6 years ago

looks promissing a few dB loss at 200MHz as far one can see on this picture. But why the FFT mode, why not plain time domain. Measure 200MHz without sweep and some other frequencies below to compare.

ViolationMad

6 years ago

Did that too ofcourse and it gave me the same results. I just made FFT for the pic in this thread so one can see a direct comparison in one picture.

hurz

6 years ago

BTW, you control the ADF4351 with STM32?

ViolationMad

6 years ago

Yeah right, but it is on the evaluation board already. First I wanted to do it myself but I barely have time at the moment so I just got the full thing.

rich11292000

6 years ago

All the new cheap stuff I look at has upgrades through a software key, just seen one that's a 40 day free trial for a $350 scope

kiani

6 years ago

Congratulations on your new scope.

ViolationMad

6 years ago

@kiani Thanks man ^^. I got that thing for almost 4 years tho haha.

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