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Re: [Amps] Roller Inductor specs

To: <sacramento.cyclist@gmail.com>, <amps@contesting.com>
Subject: Re: [Amps] Roller Inductor specs
From: Karl-Arne Markström <sm0aom@telia.com>
Reply-to: Karl-Arne Markström <sm0aom@telia.com>
Date: Mon, 16 Feb 2009 09:09:50 +0100 (CET)
List-post: <amps@contesting.com">mailto:amps@contesting.com>
On a "sunny day" the BC-375 put out about 60 - 100 W CW or AM carrier.

The roller inductor was part of a matching network that series-tuned 
the aircraft wire antennas
at the lower HF frequencies. Rated "antenna current" at these 
frequencies was 3.5 - 4 A.

As a "guesstimate", the wire size used in the BC-375 roller inductor 
would be able to carry about 5 A RF current at HF frequencies. Heating 
due to skin effect is the primary limiting factor.

73/

Karl-Arne
SM0AOM





----Ursprungligt meddelande----
Från: sacramento.cyclist@gmail.com
Datum: 2009-02-16 06:20
Till: <amps@contesting.com>
Ärende: Re: [Amps] Roller Inductor specs

Thank you all for the replies.

I'm still curious what power level a 5 amp rated (as Karl suggests)
inductor would be appropriate to use in.  A simplistic I squared R
calculation yeilds over a KW at 50 ohms, but I don't know what impact
skin effect or circulating currents have.

I also found contradictory info on the BC-375.  One source says it a
600-800 watt input transmitter, but other sources suggest a much lower
power unit.  I'm inclined to believe its in the 100 watt class given
its appearance.

      Dennis

On Sun, Feb 15, 2009 at 11:22 AM, Karl-Arne Markström <sm0aom@telia.
com> wrote:
> This is the roller inductor from the BC-375 airborne transmitter.
>
> If memory serves me right it is about 18 uH inductance with an 
approx. 5
> ampere RF current rating.
>
> 73/
>
> Karl-Arne
> SM0AOM
>
>
> ----- Original Message ----- From: "Dennis Wade"
> <sacramento.cyclist@gmail.com>
> To: <amps@contesting.com>
> Sent: Sunday, February 15, 2009 8:07 PM
> Subject: [Amps] Roller Inductor specs
>
>
>> Good morning,
>>
>>      Could someone look at Ebay item  110349006314 , and tell me
>> what they might know about what piece of equipment this roller came
>> from, power level it was used at, etc.  I have three of these and my
>> impression is that they are fairly common.  I'm particularly curious
>> what the ratings of such an inductor might be (i.e. how big an amp
>> might it be used in.
>>
>>        Thanks for the info,
>>
>>        Dennis
>>

-- 
Dennis L. Wade
KG6ZI
Carmichael, CA
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