[Elecraft] Elecraft DMM vs VOM

Thu Mar 27 13:20:01 2003

Hi

If Bob doesn't mind. The resistor isolates the RF circuit from the
capacitance of the DVM and the inductance of the leads. Many times just
probing a RF circuit will upset it or in some cases causes it to stop
working. The high input resistance of the DVM prevents the resistor at the
probe tip from affecting the reading much.

BTY this is the same reason a X10 probe is used on a scope, more to reduce
the loading capacitance rather than the resistance. The resistance is
increased by 10 but the capacitance is reduced by 10

Don Brown
KD5NDB

----- Original Message -----
From: <[email protected]>
To: "Bob - AG5Q" <[email protected]>; <[email protected]>
Sent: Thursday, March 27, 2003 10:32 AM
Subject: Re: [Elecraft] Elecraft DMM vs VOM

>
> Thanks for the tips Bob. But why do you need a resistor to isolate the
> probe if the DVM has a very high impedance anyway?
>
>
>
>
>
> "Bob - AG5Q" <[email protected]> on 27/03/2003 15:58:56
>
> To:    <[email protected]>, <[email protected]>
> cc:
>
> Subject:    Re: [Elecraft] Elecraft DMM vs VOM
>