| Products > Test Equipment |
| Siglent SDS1000(X) / SDS2000(X) or LeCroy WaveAce (Blackfin) hacks? |
| << < (9/19) > >> |
| markus_jlrb:
@KeBeNe, looks very ipressive, -3.6dB at 460MHz. But I wonder about the increased voltage level at low frequencies. You have terminated the dso input with 50 Ohm properly? Sorry that I ask. It's a big difference if I compare with my scope. Did you make other mods? Btw what is your smallest time base value. 1ns or less? Markus |
| KeBeNe:
So, the SMT06 is no longer in ALC mode at 1V, the levels are no longer true. I did not pay attention. We should agree on measurement levels and settings on the SDS (setup file from the SDS). For the measurements, I activate the internal 50ohm resistor. 1ns is my smallest time. Other modifications than the 4 capacitors removed I have not done, maybe there is still a calibration file, that would be an explanation |
| markus_jlrb:
@KeBeNe I have modified your pic with some markers. Now It's look for my more realistic. Thanks for your effort! Markus |
| markus_jlrb:
In addition to this BW picture, it would be of interest if someone could measure the input impedance of the scope channels when terminated (internally) with 50Ohm up to 150% of the BW - let say to 500MHz. The theoretical BW according to Nyquist with 2Gs/sec is 1000MHz. Taking the drop of a aliasing filter 600 to 700 MHz in BW should be possible. The AD83700 is specified -3dB@750MHz. I compare this with the Lecroy models with 2Gs compatible with the SDS230xX that are specified up to 400++MHz. Markus |
| markus_jlrb:
FYI, I have made the effort and check the reflection on ch1 to ch4 om my SDS2204X model. Looks not very good according to my opinion. 10dB reflection from 50 Ohm terminated port/channel means (>3% voltage err or 10% power error) error in maesurement - right? I had check the spawn from 0 to 1000MHz. At the point of 100mV/div coming from the top (10,5,2,1,0.5,0.2V) the reflection change due to internal switching of components. All pictures show 50 Ohm terminated channels beside one that I measure with 50 Ohm disabled (1Meg). So I present screenshots of my measuring device as well as swr bridge and cabling and the dso screenshots. Waiting for your comments. Markus Sorry pic. #7 should be labeled with CH3 and not CH1. |
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