My ERP on 137.766kHz is.......

Thanks to G4FEV, I've just realised that I made a fundamental mistake measuring my field strength, forgetting to turn off the AGC when taking the measurements of my signal relative to DCF39. Whereas my initial measurements indicated the ERP was in the low mW region, in reality my signal is much, much weaker. For example, G4FEV reckons my signal is some 70-80dB weaker than DCF39 where he is, if not more! So, tomorrow I shall have to try the test again and see if I can get a sensible figure with AGC turned OFF.

G3XDV's screenshot of my QRSS3 LF signal this afternoon.

Mike G3XDV (61km) has just sent me a very comprehensive report with 178 screenshots of my QRPp signal over the last 30 hours. Copy was remarkably good considering everything. Again, I am amazed how well this works.

Checking my 137.766kHz ERP by measuring field strength

Well, today has been a bit of a disappointment: my QRP QRSS3 beacon has been running for over a day on 137.766kHz and, apart from my own highly successful reception tests out to around 8km (as far as I went in the best direction) not a single station has reported seeing it  ....yet.

Tomorrow, I am going to do one more experiment using the QRSS beacon: knowing the field strength of DCF39 on 138.830kHz, a commercial station in Germany, is around 1mV/m here in the south of the UK in daytime, I want to measure the S/N of this station about 5km from home using the mag-mounted E-field probe. Then, at the very same spot, I will measure the S/N of my beacon with the same bandwidth settings and RX kit.

Based on these two measurements, I should be able to work out the ERP of my beacon to an order of magnitude and probably to within +/-3dB. The field strength of my own signal can be worked out just by comparing the S/N with that of DCF39.  Knowing the field strength and the distance from the home QTH, I can work out the ERP needed to produce this.

Any guesses what ERP I am using? I'll tell you the answer tomorrow!