| Products > Test Equipment |
| Another radio amateur about to buy a DSO ... |
| << < (12/13) > >> |
| tggzzz:
--- Quote from: Mike99 on November 16, 2023, 12:29:32 am --- --- Quote from: ebastler on November 15, 2023, 01:13:17 pm --- --- Quote from: 2N3055 on November 15, 2023, 01:02:43 pm ---Anyways, it shows 50Ω path is not made by simply putting 50Ω terminator in parallel with 1MΩ/20pF input... --- End quote --- This would be a nice opportunity to demonstrate the difference. @Mike99, any chance you could repeat the measurement with the scope's input set to 1 MOhm and an external 50 Ohm pass-through terminator? Thanks! --- End quote --- I don't have a pass through terminator, only a 6dB BNC attenuator. Mike --- End quote --- A 6dB passthrough attenuator followed by the imperfect internal attenuation will be better at reducing VSWR than an external terminator. That technique is frequently used inside equipment where components/subsystems have poor impedance matching. Basic principle: gain is easy and cheap, wideband matching is difficult and expensive. But don't stick an attenuator in front of a low-noise front end, of course :) |
| Mike99:
I have made some more measurements. First was the 50 ohm input bandwidth, measured using an RF millivoltmeter: Next was input VSWR. The graph compares the 50 ohm input with the 1Mohm input, the latter using a T piece with a 50 ohm load. Finally, the impedance of the 1Mohm input. Mike |
| Orange:
Hi Mike, An impedance plot for 50 Ohms would make this information complete :-) |
| Mike99:
--- Quote from: Orange on November 16, 2023, 12:52:39 pm ---Hi Mike, An impedance plot for 50 Ohms would make this information complete :-) --- End quote --- OK I'll do that later today. Mike |
| dshorthill:
I use this device to monitor the RF output of a 1 kw ham amplfier on my 1204xe Siglent scope. I have a bnc t with a 50 ohm termination on the scope end. Works great. https://www.ebay.com/itm/193686855709 Dave k1xd |
| Navigation |
| Message Index |
| Next page |
| Previous page |