LF: SAQ

[Dick Rollema <dickrollema@casema.nl>]

To All from PA0SE

I also had good reception of SAQ on 2 and 3 July.   The morse
code of the messages was perfect. The SAQ website of SAQ shows Lars
Kalland at the key of SAQ. So either Lars has an excellent fist or the
code came from a Creed machine running a punched paper tape.

I used the 13.15 UTC transmission on Sunday to measure the field
strength.  My single turn untuned loop of 1 x 1 square metres
produced 0.25 microvolt. This was measured at about  8 dB above the
noise of a W & G SPM-12 selective voltmeter in 25Hz bandwidth. This
works out at a  field strength of 698 microvolt/m. The reading
is  not  accurate as the meter was jumping up and down on the
morse signal, so the reading is perhaps correct within 2 dB or so. 
I take the distance between Grimeton and my QTH Leiderdorp to be 735km.
Entering 698 microvolt/m and 735km into the graphs for groundwave
propagation of CCIR Recommendation 368-7 yields a transmitted power of 6
kW over both sea water and  ":Land".  This tallies
rather well with the 7kW found by Jim, M0BMU.  

The power fed to the aerial is stated at 200kW. So 6kW radiated power
means an efficiency of (6/200) *100% is 3%. This looks low but at a
frequency of 17.2kHz it is not bad I think. (I wish I had 3% at 136kHz;
that would give me 3.6W EMRP instead of 60 milliwatt!) 

73, Dick, PA0SE
JO22GD