EEVblog #842 - Rohde & Schwarz HMO1202 Oscilloscope Teardown

[Bud]

I spotted the use of LMH6518 bandwidth controlled amplifier in the front-end. That may mean the 100MHz version of the scope (HMO1212) may be hardware hackable to 300MHz bandwidth (equivalent of HMO1232). This translates to almost $900 USD savings per the current pricing at TEquipment. In Canadian dollar + tax it is almost $1000 savings 

In the screenshots taken from the teardown video it can be seen the SPI bus going to the chip can be hijacked and a small microcontroller put in the middle to translate the bandwidth set commands. Some surgery would most likely be needed but it seems to have enough trace length to be doable. A hacked scope would have built-in 20MHz BW limit and the "Full BW" which would be whatever the hack sets it for, may be even higher than 300MHz, being limited by perhaps reliable triggering.

If I was not on my hunt for a Keysight scope I would certainly get a 1212 and try the hack. 

[EEVblog]

I spotted the use of LMH6518 bandwidth controlled amplifier in the front-end. That may mean the 100MHz version of the scope (HMO1212) may be hardware hackable to 300MHz bandwidth (equivalent of HMO1232). This translates to almost $900 USD savings per the current pricing at TEquipment. In Canadian dollar + tax it is almost $1000 savings 

I'm 90% sure that's the case 
I might open mine up tomorrow. More fun than a software licence hack (not that I know how to do such things).
Of course it's only right to use the logic analyser probes to probe it's own clacker 
A few scopes have this same chip.

The software bandwidth in the LMH6518 is 350MHz though, so it's likely the upper limit is set by other stuff in the front end circuitry.
The 100MHz and 200MHz are surely just enabling this via SPI though.

[Bud]

if the scope bandwidth is upgradeable then i guess the probes are 300MHz ones for all of them.

[pa3hfu]

if the scope bandwidth is upgradeable then i guess the probes are 300MHz ones for all of them.

Check!! ;-)
RT-ZP03 (300 MHz -3 dB) with my HMO1212.

[Nozzer]

I wonder what the bandwidth upgrades cost relative to saving up and buying an instrument with a higher bandwidth? Unfortunately I cannot seem to find anywhere where this information is available.

It would also be interesting to know if they are going to produce an upgraded version of their HMO2024 with the 128kb FFT and bandwidth going beyond the current 200MHz.

[zapta]

I purchased a 100Mhz version and got a basic version (70Mhz ?) and a bandwidth upgrade license to apply myself. The price of a base unit + update bundle depends on each seller.  I also got with the same bundle a license for protocol decoders.

[Fungus]

I wonder what the bandwidth upgrades cost relative to saving up and buying an instrument with a higher bandwidth? Unfortunately I cannot seem to find anywhere where this information is available.

It's in their online store: 
50MHz -> 70MHz upgrade: 98 Euros
50MHz -> 100MHz upgrade: 198 Euros

[xmegacorel]

I've bought the model hmo1212, but without logic analyzer unit. The price is 300 euro for old version and 360 euro for new one.
Is anybody try to copy this unit? I saw the teardown video and this unit is simple to copy.
Some users wrote that the logic analyzer unit doesn't has hardware protection.
I know that is much more simple to buy Chinese copy of logic analyzer Logic 8 or Usbee.

[nowlan]

They had an educational pack for the probes. Maybe find a student to buy a set for you?
http://www.tequipment.net/Rohde-&-Schwarz/HMO-ED01/Options/

I got quoted a similar price when i enquired about the units when released in 2014. I did use my student email however.

I wonder if they would negotiate a better/similar price for you, seeing as stand alone logic analyzers are cheaper.
Maybe follow up with the place you bought yours from.

[xmegacorel]

http://support.saleae.com/hc/en-us
Logic 8 costs 219$. It has very very powerful software with infinite buffer and more then 10 type of protocols, works with input 5..1,8V.
R&S have to cost less then 100$. Otherwise unreal to imagine who can buy this bundle.

[rysiontko]

Some users wrote that the logic analyzer unit doesn't has hardware protection.

Do you have any more info, or even better the source?

[View[+]Finder]

QUESTION: Battery Powered Operation

Thanks Dave for the teardown--I now have a new 'scope. The HMO1212 is every bit as usable as was indicated in the #842 and will be my portable for work outside the lab. Battery power was speculated in the blog, so I had to check that out. Why? Some of the work I do is on boats and the AC comes from inverted DC (enough on that).

The three-wire cable from the 'scope internal PS to the board is 12V, ground and an AC signal for line-sync, so the battery in my design would substitute for the PS as needed using a barrel plug with a 'disconnect' on the PS 12V when it plugs in. No problem there.

The 'scope draws about 1.3A when working and a bit more on startup, so my battery choice would be a LiPO 3S with 5,000mAH capacity. I bought a Mean Well 12V DC-DC converter for the input thinking that it would keep the 12V steady. Testing the setup with a voltmeter and an electrical load showed that the LiPo battery voltage was far more stable than the 'regulated output' from the converter--probably a good explanation, but I don't have one--so I have had a re-think.

What about using the LiPo without the regulator? Fully charged it is ~12.4V and drops down to 12.3V under a load of 1.3A (like the 'scope). As the battery is drained, the voltage goes down: now 11.85V after 45 minutes. I would not run much below 11 volts for the work I envisage doing on battery.

Here's my question: How 'safe' is it to operate the HMO1212 on voltage ranging from 12.4V to 11.0V? (assume that there is no sagging on changes in the settings on the scope) Also, how safe is it to test this in advance by varying the voltage with a bench PS using the three-wire cable above? (Note: I have tried this without any indication of trouble, but that might just have been luck)

(By 'safe' I mean for the HMO1212, not for me--the mains cord is disconnected, etc.)

Thanks,
Donal

Update: my HMO1212 operates 'as normal' from 11.0V to 12.5V on the bench PS. Below 11V there is a change in the display of a 1 MHz trace as Dave used for the FFT demo.

[hazzer]

Hello Donal

Id be interested in any follow up info you have on fitting a battery to the 1202, are you intending to have the battery inside the case or as an add on pack?

Harry

[zapta]

The HMO1002 doesn't need or have a fan so potentially it requires less power to operated.

[zapta]

The other day it happened again. I connected the probe to the external trigger input. Enough is enough. Just ordered a BNC dust cap.

http://www.ebay.com/itm/280559866563

;-)

Edit: why waiting for a package from China if I can 3D print a dust cover?  http://www.thingiverse.com/thing:1778219

[heavenfish]

Nice tear down!

I don't think the ADC is a bad design choice, because there's ADC08D1020 to replace directly. It's probably a procurement choice to use either of them. There's also ADC08D500 with same package, it may be used in HMO1002 to save some extra money in low end.

The three SRAMs should be used by 2 analog channels and 8 digital channels. My question is where is the memory for waveform buffer? If done in Atmel processor how can it gets to 10k wfm/s?