[Lowfer] Antenna current measurement - LEM current sensor?

[N8OOU]

Hi Ben,

I have finally gotten my issues  and understanding of RF ammeters under 
control thanks to the suggestions and explanations from the members of 
this maillist.  I have been able to set up a test/calibration stand 
which provides repeatable results. As well as meters using three 
different circuit designs which indicate equal readings.

I looked into the specs of this device and can see where this type of 
device could be a benefit for remote reading of P.A. Input and Antenna 
Current.

I think manufactures put ratings on components that are on the 
conservative side to insure the part remains reliable and can produce 
repeatable results. Very frequently the part can be used outside it's 
specified range in conditions of lower power, or less tolerance, or 
lower performance. The device is very likely usable at 500 kHz or maybe 
even double the bandwidth.

The cost of the part is high compared to other solutions, and I agree 
the extra circuitry for displaying the readings puts it in the "nice to 
have" category.  It sure would be nice though, to measure how the 
antenna is doing from the warmth of the house.

Thanks for the find.
73   de   N8OOU - Mike Meek

On 11/30/2014 03:39 PM, Ben Hall wrote:
> Afternoon all,
>
> Some time ago I needed to make some current measurements.  A search for
> a solution lead to me to Hall Effect current sensors made by LEM.
>
> With the talk of antenna current measurement, knowing that the LEM
> sensors can measure AC and DC current, I decided to see what the data
> sheets listed for frequency range.
>
> Several models have a -3 dB bandwidth of 400 kHz:
>
> <http://www.digikey.com/product-detail/en/HLSR%2032-P/398-1123-ND/4331980>
>
> <http://www.lem.com/docs/products/hlsr-p%20series.pdf>
>
> While no-good for the ~500 kHz band, maybe useful for LOWFERs?
>
> I will admit that at $14 a pop, plus the need for additional circuitry,
> they are probably less useful than the transformer-rectifier units that
> are self-contained and self-powered...
>
> thanks much and 73,
> ben, kd5byb
>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>