Siglent SDS1202X-E or Rigol DSO1054Z (yes, another one)

[nctnico]

GW Instek is really overpriced in EU, no idea why. Maybe not a big market enough to offer volume discounts. Does anyone know if the scope is 100-240V (the GW Instek 1054b) and do they offer world wide warranty or is regional? Testequipment have it on sale at $360, I might swallow the pill of paying extra VAT and import duties + ridiculous postage to Bulgaria if it comes with waranty.

The GW Instek has a limited lifetime warranty (which ends 5 years after they stop making the model) but you have to send it back to the dealer you got it from. All in all buying from TE may be an option but it wouldn't hurt to haggle a bit with a local dealer to see if they can match the price. BTW you have to compare ex-VAT prices because AFAIK all prices shown in the US are without VAT.

Another option would be the MicSig TO1074 which is 389 euro ex. VAT from Batronix.de .

[klaff]

Regarding bandwidth limitations, the Siglent SDS1202X-E manual states: "At 2 mV/div volt scale, the BW Limit is set to 20M automatically, and cannot be turned off." I assume that also applies to 1 mV/div and 0.5 mV/div settings.

[Andreas]

Hello,

if you calculate the Johnson noise at 200MHz for a 1Meg input resistor then you know the answer.

With best regards

Andreas

[rf-loop]

Regarding bandwidth limitations, the Siglent SDS1202X-E manual states: "At 2 mV/div volt scale, the BW Limit is set to 20M automatically, and cannot be turned off." I assume that also applies to 1 mV/div and 0.5 mV/div settings.

Manual version UM0101X-E02A  have some errors.
Two tiny examples:

This BW limit  is one error.

Truth is that it have full BW  with all V/div settings including 500uV/div to 2mV/div.
(also  full ADC resolution with these V/div's, unlike Rigol)

Here other error.

Manual: "The range of the horizontal scale is from 2ns/div to 50s/div"
Also this is wrong. Right is 1ns/div to 100s/div.

[rf-loop]

Here some kind of measurement about 500uV BW.

Signal from HP8642B, level adjusted for show 1Vrms level in scope with 20MHz (Gen output displayed level -46.7 dBm in this case).
Oscilloscope use  gated measurement and adjusted for one cycle.

Cable between Gen and Scope is Sucoflex 104PEA. Oscilloscope input terminated with Tektronix 011-0049-01 BNC Feed Thru 50ohm  + N-BNC adapter.

First image 20MHz and second image 200MHz.  For better measurement accuracy in this case, trace average mode  is in use instead of eres..

This give enough evidence that 500uV works with full BW.

[boggis the cat]

Here are some tests I just ran, to see what effect (if any) the lower V/div settings have on bandwidth.  This was done using an oscilloscope calibrator: Wavetek 9500 and 9520 Active Head.

First are 3 Vpp signals to establish a baseline:
50 kHz ref


200 MHz


Next are 5 mVpp signals with V/div set to 1 mV/div:
50 kHz ref


200 MHz


Final two are 4.44 mVpp signals (lowest amplitude available) with V/div set to 500 µV/div:
50 kHz ref


200 MHz

[klaff]

Good to know, thanks. I did try last night and noticed that no bandwidth limit indication showed up at the small scales, but didn't have a good source to check the bandwidth.

[boggis the cat]

Retests today, after running the 'Do Self Cal'.  Tests run using an oscilloscope calibrator: Wavetek 9500 and 9520 Active Head.

CH 1

First are 3 Vpp signals with V/div set to 500 mV/div to establish a baseline:
50 kHz ref


200 MHz


Next are 5 mVpp signals with V/div set to 1 mV/div:
50 kHz ref

* See note below.

200 MHz


Final two are 4.44 mVpp signals (lowest amplitude available) with V/div set to 500 µV/div:
50 kHz ref


200 MHz



CH 2

First are 3 Vpp signals with V/div set to 500 mV/div to establish a baseline:
50 kHz ref


200 MHz


Next are 5 mVpp signals with V/div set to 1 mV/div:
50 kHz ref


200 MHz


Final two are 4.44 mVpp signals (lowest amplitude available) with V/div set to 500 µV/div:
50 kHz ref


200 MHz



* A note on the triggering.  The triggering was a bit erratic (switching between rising and falling) at the 50 kHz ref frequency for the 1 mV/div and 500 µV/div settings.  I deliberately set the trigger point to zero, so this may be a harsh case.