Author Topic: Extending probe-cable on Rigol DS1102 - Any advice  (Read 1676 times)

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Offline bob_60

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Extending probe-cable on Rigol DS1102 - Any advice
« on: April 24, 2013, 12:13:58 am »
Hi. I need to extend the probes about 2 meters. Does anyone have any advice on how to achieve the best result.

I'm thinking about Coax - but what type (impedance) should I choose. And what about a terminator for the cable.

The object to test, is running at about 10 - 20MhZ (5V).



Any advice is appreciated.
/Bo
« Last Edit: April 24, 2013, 12:27:13 am by bob_60 »
 

Offline ben_r_

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Re: Extending probe-cable on Rigol DS1102 - Any advice
« Reply #1 on: April 24, 2013, 12:33:12 am »
If you cant figure another way out, I use and recommend the modular series from Fluke as they have a lot of options including extenders.
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Offline amspire

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Re: Extending probe-cable on Rigol DS1102 - Any advice
« Reply #2 on: April 24, 2013, 01:00:29 am »
Hi. I need to extend the probes about 2 meters. Does anyone have any advice on how to achieve the best result.

I'm thinking about Coax - but what type (impedance) should I choose. And what about a terminator for the cable.

The object to test, is running at about 10 - 20MhZ (5V).



Any advice is appreciated.
/Bo
Conventional scope probes are not designed to be extended.

At 10 to 20MHz, you would be better off making your own 20:1 cable with a 1K input impedance. A 15pF x10 scope probe at 20MHz has an input impedance of 500 ohms, and a homemade 1K probe may actually work much better. probably better risetime.

The cable is a good quality 50 ohm cable  - whatever length you need - terminated with 50 ohms at the scope end. At the sensor end, you have a 950 ohm SMD resisistor in series with the inner core of the cable.
 

Offline Psi

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Re: Extending probe-cable on Rigol DS1102 - Any advice
« Reply #3 on: April 24, 2013, 01:05:42 am »
Hi. I need to extend the probes about 2 meters. Does anyone have any advice on how to achieve the best result.

I'm thinking about Coax - but what type (impedance) should I choose.

Manufactured scope probes use special resistive cable and the exact resistance is part of how the probe is designed. (Watch dave's recent video on the subject)
Adding coax onto an existing probe will upset the characteristics.

As said above, you need to make your own probe
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