Series resistor sets impedance?

[neazoi]

Hi, I have a 50 ohm output HF (1-30MHz) signal generator.
What if I put a series 10k resistor on it's output (center lead of the coaxial)?
Will it increase the impedance seen by external devices connected to it, to about 10k?

For the time being please ignore the effects of signal attenuation, just focus on the impedance set.

 

[volker@muehlhaus]

What if I put a series 10k resistor on it's output (center lead of the coaxial)?
Will it increase the impedance seen by external devices connected to it, to about 10k?

yes

 

[KlausST]

What if I put a series 10k resistor on it's output (center lead of the coaxial)?

A resistor has two legs.
Your description only tells where you connected one leg .. but what did you do with the other leg?

And if you say "increase" ... this means there are two situations: one with the resistor, one without the resistor. You should give clear informations for both situations..
Where exactly are the "external devices" connected?

As so often... I tiny effort to take a pencil and a paper .. would be so helpful.

Klaus

 

[neazoi]

A resistor has two legs.
Your description only tells where you connected one leg .. but what did you do with the other leg?

And if you say "increase" ... this means there are two situations: one with the resistor, one without the resistor. You should give clear informations for both situations..
Where exactly are the "external devices" connected?

As so often... I tiny effort to take a pencil and a paper .. would be so helpful.

Klaus

1st case: 50 ohm generator connected to a filter
2nd case: 50 ohm generator connected to a 10k series resistor and the other resistor lead to this filter.

Will the input of the filter "see" a 10k input impedance?

 

[volker@muehlhaus]

Will the input of the filter "see" a 10k input impedance?

Your previous question was clear enough, the answer has not changed: yes, the filter will "see" 10kOhm source impedance (10 kOhm + 50 Ohm in series)

 

[albbg]

This is completly true only in theory, because any connection, even short, between the 10k resistor and the filter will alter the impedance, since you system is not matched.
The worst case is the resistor directly connected at the output of the generator, then a coax to go to the filter.
The best case is the coax cable connected to the generator, then the 10k connected as close as possible to the filter.
Furtermore any parasitics capacitance to ground at filter side will play a role.
Of course low frequency behaves better.

What's about the purpose of this added 10k resistor ?

 

[FvM]

Which filter has 10k input impedance? Intended frequency range?