On 16 July 2015 at 08:05, Ole Stender Nielsen <[email protected]> wrote:
> I use a home-made untuned loop antenna with 4 windings of 2.5 mm2 > insulated wire on a 80 x 80 cm wooden frame, and with a grounded base > pre-amplifier mounted on the antenna frame. A schematic is enclosed for you > to copy. > The pre-amplifier is powered through the cable, and loads the FS700 input > as required. > I live about 290 km from the island of Sylt, and get nice noise margin > figures from the FS700, normally about 40 dB, often up to 46 dB. > A couple of questions 1) Do you have any suggestions for a replacement for the LM394CN, which is obsolete and unobtainable from any reputable source? There are plenty on eBay for a few $'s from China, but the probability of them being fakes is greater than 0.99. The MAT12 seems to be one possible candidate for a replacement and while not cheap, is available from reputable sources like Farnell. 2) What is the "Ca. 3 Ohm" to the left of your circuit? Is that what you estimate the input impedance is? I've got 95 m of 2.5 mm^2 wire. The resistance of that is about 7.41 mOhm/m so my 95 m would have a DC resistance of around 7 Ohms if I used it all. I have built the loop 1.0 x 1.2 m. Hopefully that will be ok to receive at least one or both of * Lessay, France, power = 250 kW, distance = 321 km, bearing = 211 degrees. * Anthorn, England, power =- 250 kW, distance = 419 km, bearing 331 degrees. I now need to work out how many turns to put on it. Dave _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
