Topband: Non-inductive resistors

[Sinisa Hristov]

Joe Wilkowski wrote:
 
> Folks,
> can anyone recommend a source for relatively inexpensive non-inductive resistors.  I have exhausted my supply.  I need  ~ 6 or so resistors in the  450-500 ohm range (1 watt or better) for my beverages.  They are hard to single source and very expensive even in lots.  In addition, many  manufacturers say they are non-inductive but that is not necessarily true at 1.8 MHz.    Carbon composition seem to be the only non-inductive resistors at 2 MHz.


In the 500 Ohm range at 1.8 MHz resistor inductance
is generally not a problem (except with wirewound).
To get only 1 Ohm of reactance takes 88 nH of inductance.
Most general-purpose resistors are well below that value.
Even 10 Ohms (880 nH) are insignificant, changing
the phase angle by a mere 1.1 deg.

In this resistance range parallel capacitance
is generally more of a problem. However, at 1.8 MHz
that is also insignificant, as it takes 3.5 pF for a
similar phase angle change.


73,

Sinisa  YT1NT, VA3TTN