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Re: [Amps] reducing the reactance of a wirewound resistor

To: Vic K2VCO <>, "" <>
Subject: Re: [Amps] reducing the reactance of a wirewound resistor
From: "Fuqua, Bill L" <>
Date: Mon, 6 Feb 2012 02:06:58 -0500
List-post: <">>
check out these resistors.
also click on the General Specifications tab and you will find a picture of the 
counter wound wires.
Bill wa4lav

From: [] On Behalf Of 
Vic K2VCO []
Sent: Sunday, February 05, 2012 7:01 PM
Subject: Re: [Amps] reducing the reactance of a wirewound resistor

What HB9SLV suggested was not exactly an Aryton-Perry winding, although the 
principle is
the same. Instead of being in parallel, his idea had the windings in series. So 
they will
always carry the same current!

On 2/5/2012 9:23 AM, jeff millar wrote:
> Interesting... I looked up Aryton-Perry winding as a result.  The Wikipedia
> entry pointed out ...
> "One disadvantage is that because the two lengths of resistive wire are
> connected in parallel, four times the length of wire (twice the length for
> each coil) is needed to make a given resistance than if a single coil was 
> used."
> That led to the realization that the two windings have to carry the same 
> current
> to have the magnetic fields cancel...which means they have to have the same
> resistance.
> Conclusions...
>      - start with 100 Ohm wire wound resistor
>      - count the turns
>      - wind 100 Ohms worth of copper over the same length
>      - for same turn count, need smaller diameter wire
> jeff, wa1hco
> On 02/03/2012 03:23 AM, Angel Vilaseca wrote:
>> 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
>> _______________________________________________
>> Amps mailing list
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> Amps mailing list

Vic, K2VCO
Fresno CA
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