LF: Re: F6CNI to night testing a tuned loop TX on MF

["F6CNI - Andy - JN19QB" <f6cni@orange.fr>]

Hello Andy.

 

Well done, I am also very impressive. All datas are so close !

 

I just download your EXCEL file.

 

I live in Château Thierry, in the Region of wines of champagne.

Congrats, and this glass is for you !

 

Andy F6CNI.

 

 

From: Andy Talbot

Sent: Tuesday, July 28, 2015 11:12 AM

To: rsgb_lf_group@blacksheep.org

Subject: Re: LF: F6CNI to night testing a tuned loop TX on MF

 

That is interesting, and encouraging.  I inserted your loop parameters into a spreadsheet I wrote many years ago in the early days of LF to calculate the properties of loop antennas.   As the spreadsheet is designed to work with circular l loops I used a diameter of 9.45m to give the same area as your 7m x 10m rectangular loop.

 

The results come out very close to the values you give from measurement.

and for your loop, the spreadsheet figures can be seen below:

The ERP for 1W of RF shows as -22.5dBW which is so close to your 6mW as to be almost impressive!

 

The spreadsheet (with different values inserted) can be found at http://www.g4jnt.com/DownLoad/MagLoop.xls

 

Andy  G4JNT

 

Frequency	0.475	MHz		Loop area	70.14	m^2
Loop Diameter	9.45	m		Radiation res	9.64E-04	Ohm
Conductor dia	10	mm		Tot Cond Length	29.69	m
No. Conds. (Litz)	1			Winding Length	29.69	m
No. of turns	1			Inductance	41.16	uH
Resistivity	1.7E-08	Ohm/m		Skin depth	9.52E-05	m
rel Permeability	1			RF Resistance	0.169	Ohm
				Xl	123	Ohm
Tx Power	1	W		Q	724
				Bandwidth	656	Hz
				Efficiency	0.0057
				"	-22.5	dB
				Resonate Cap	2.7	nF
				Current	2.4	A
				Voltage	298	V
				ERP	-22.5	dBW