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Oscilloscopes and signal sources

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elroy:
A couple of questions about feeding signal sources to a Siglent SDS1202X-E oscilloscope:

-- For various tests, I'm planning to input reference signals to the scope from sources such as frequency standard, a frequency calibrator, and a VNA in frequency generator mode. I gather that rather than using the scope's probes, it's common to feed such signals into a scope using cable with appropriate connectors on each end (in the case of the devices I'm working with, this would generally be SMA to BNC). Do I need to worry about anything like voltage or power levels? I assume that scopes like this can handle a range of inputs from devices of this type, but want to make sure I don't overlook anything before starting to plug anything in. Is there a general rule of thumb about voltage or power levels that are and aren't safe for a modern digital scope like this? (I obviously wouldn't, for example, feed the RF output of a 100w ham transmitter directly into a scope.)

-- As for the cable to use for connections like this, I have a lot of RG316 coax with SMA connectors on each end in various lengths, as well as SMA-to-BNC adapters. Does this seem adequate for most oscilloscope test purposes, or should I consider investing in anything else? I've seen mention made of higher-end cables such as Suhner, and wonder if that would be worth the investment.

KrudyZ:
The SDS1202X-E only has 1M Ohm inputs.
To connect a signal source via a coax cable, you would need to add external 50 Ohm feed-through termination at the input to the scope.
The scope will be able to handle any voltage your generator is likely able to produce, so the termination will be the limiting factor. Do not exceed its power rating.
RG316 will be perfectly fine for any signals that the scope can work with, since its upper frequency limit is 200 MHz, far below the limit of RG316.

elroy:

--- Quote from: KrudyZ on December 04, 2018, 04:22:40 pm ---To connect a signal source via a coax cable, you would need to add external 50 Ohm feed-through termination at the input to the scope. The scope will be able to handle any voltage your generator is likely able to produce, so the termination will be the limiting factor. Do not exceed its power rating.
--- End quote ---

Thank you, that's very helpful. Would something like this be appropriate?

https://www.amazon.com/Pomona-4119-50-Terminator-Feed-Through/dp/B00JJ4EWU2/

rstofer:
Yes, that terminator will work.

Sometimes people put a T fitting at the scope.  The leg of the T goes to the scope and the signal comes in on one arm and a dead end terminator goes in the other end.

Scroll down about 1/5 of the way and you'll see a 'kit' with T's and terminators along with a coax $20
https://www.amazon.com/CablesOnline-Terminator-Adapter-2-Pack-R-3006-2/dp/B00G10MKCO

HB9EVI:

--- Quote from: elroy on December 04, 2018, 05:08:12 pm ---Thank you, that's very helpful. Would something like this be appropriate?

https://www.amazon.com/Pomona-4119-50-Terminator-Feed-Through/dp/B00JJ4EWU2/

--- End quote ---

that's ok for signal levels like from a FG, but don't get the idea to feed 100W for a ham tranceiver in it.

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