[Amps] reducing the reactance of a wirewound resistor

[John Lyles]

Do you mean Aryton-Perry winding? Check it on google.
John
K5PRO



>> Date: Fri, 03 Feb 2012 09:23:20 +0100
>>> From: Angel Vilaseca<avilaseca at bluewin.ch>
>>> Subject: [Amps] reducing the reactance of a wirewound resistor
>>> To: amps at contesting.com

>>> Hi all
>>>
>>> I have a nice large 50 ohms wirewound resistor, which I would like to
>>> use as a dummy load. Problem is, it is inductive of course.
>>>
>>> To cancel the inductive reactance I was thinking of winding some
>>> enameled wire all along over the resistor, with as many turns as the
>>> resistive wire, solder the enameled wire to the resistor terminal at
>>> one end and feed the RF at the other two separate terminals (wire and
>>> resistor) at the other end.
>>>
>>> The idea is that the inductive reactance of the resistor winding and
>>> the enameled wire winding will cancel each other. With some care and
>>> measuring gear the remaining reactance could be very low. The assembly
>>> would then behave almost as a pure resistance.
>>>
>>> Of course, care should be taken not to reach too high temperatures,
>>> because the enameled wire would then be damaged.
>>>
>>> Also, the added winding should be wound in the appropriate diraction (
>>> CW or CCW depending of the winding direction of the resistive wire)
>>> otherwise the two inductances would add instead ao canceling each
>>> other.
>>>
>>> Has anyone alredy tried this?
>>>
>>> 73
>>>
>>> Angel Vilaseca HB9SLV