CP-1 Coupler

[Paul T. Rubin]

Thanks to all who responded to my question about termination.

 

Now another: What is the limiting factor in the power rating of the coupler?
With either the 20db (max 25W), or the 30db (max 250W) the power delivered
to the secondary is 0.25W. The terminating resistors are rated at 3W. Are
there high circulating currents in the core that limit the power level, or
is there some other mechanism that I am overlooking? Is the power rating of
a torroid something that can be calculated in the design, or must it be
derived empirically?

 

As always, thanks fer learnen me something,

 

Paul N8NOV

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[Don Wilhelm-3]

Paul,

The circulating current in the secondary winding of the transformers limit
the power handling capability.  If you want to know more about this type of
directional coupler, refer to John Grebenkemper's (KI6WX) Tandem Match
article which has been featured in many issues of the ARRL Handbook as well
as the Antenna Book.

73,
Don W3FPR

> -----Original Message-----
>
> Now another: What is the limiting factor in the power rating of
> the coupler?
> With either the 20db (max 25W), or the 30db (max 250W) the power delivered
> to the secondary is 0.25W. The terminating resistors are rated at 3W. Are
> there high circulating currents in the core that limit the power level, or
> is there some other mechanism that I am overlooking? Is the power
> rating of
> a torroid something that can be calculated in the design, or must it be
> derived empirically?
>
>

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[N8LP]

For more info on the dual xfmr coupler read go to
www.telepostinc.com/lp100.html and click on the QEX article link near
the top of the page. In the article I address many of the issues related
to the coupler design, with footnotes to relevant  design references.
The original design dates to US Patent # 3426298 by C. G. Sontheimer and
R. E. Fredrick in 1969.

73,
Larry N8LP



Paul T. Rubin wrote:

> Thanks to all who responded to my question about termination.
>
>  
>
> Now another: What is the limiting factor in the power rating of the coupler?
> With either the 20db (max 25W), or the 30db (max 250W) the power delivered
> to the secondary is 0.25W. The terminating resistors are rated at 3W. Are
> there high circulating currents in the core that limit the power level, or
> is there some other mechanism that I am overlooking? Is the power rating of
> a torroid something that can be calculated in the design, or must it be
> derived empirically?
>
>  
>
> As always, thanks fer learnen me something,
>
>  
>
> Paul N8NOV
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft   
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
>
>  

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