Products > Test Equipment

Show us your square wave

<< < (65/109) > >>

TiN:
Upgraded/downgraded my scope at work. Not a fan of new Tek UI, so much button dodging and multilevel menus..  :wtf: Old Windows/PPC-based TDS5034B was sorta easier.

Square wave measure of own calibration output in the TDS7704B : ~260ps into 50Ohm.
Brand new MDO4054C with same 1:1 BNC cable measuring same cal output of TDS7704B : ~800ps into 50 Ohm.

tggzzz:
Output from a Tek 1502 TDR driving a Tek 485, Tek 2465, and Tek 2445B, all terminated with an internally with 50ohms. The Tek 1502 risetime is ~50ps, and the Tek 485 timebase is 1ns/div with a risetime of ~900ps.

The Tek 1502 output shows two clear phases

* one in which it determines the "bias point" of the tunnel diode
* the other in which is biassed to just below that point and then triggered to produce the pulse that is measuredGiven the duration of each phase, 37us, it is a testament to the Tek engineers of >40 years ago that the 1ns edge is so clearly visible.

lty1993:
Source:
1. Rigol MSO2302A-S Internal Source (Attachment 1) [15Mhz]
2. Rigol DG4202 (Attachment 2 and 3) [25Mhz and 60Mhz]

Display:
1. Rigol MSO2302A-S

Direct Coax and 50Ohms load.

guenthert:
For contrast and completeness' sake below results I got from an Analog Discovery 2 with the BNC adapter module:
(output shunted with built-in 50Ohm terminator, set 1V symmetric square wave)
input was not terminated (uses ~1MOhm "high impedance" input, DC coupled)

top to bottom:

- 8' BNC cable, 5MHz (the signal generator offers 10MHz, but then not much of a square is left)
- 8' BNC cable, 1MHz
- 100MHz 10x probe, 1MHz (system is in a bit of a noisy environment, I think the probe picks up some RFI)
- 100MHz 10x probe, 5MHz
- 8' BNC cable, input terminated via T-piece and 50Ohm terminator, 5MHz
- FFT of the last one

capt bullshot:
I believe, it's been done before, but I did hack a few components together to produce a quite nice square wave. The basic concept is a HC14 oscillating at a non important frequency and driving a LVPECL level translator. It's outputs have emitter resistors of 100R to GND, and AC coupled (10uF || 100nF) to a back terminated 50 Ohm line (Rs = 43R according to the OnSemi application note. Running some RG174 to the 50R scope input shows a clean trace, the scope reads about 300ps rise/fall time (I don't have access to a faster than 1GHz scope). So nothing very exiting, but easy to build, took about one hour to complete.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod