Hi Paul-Henrik, I bought a few crystals from this ebay seller: http://www.ebay.com.au/itm/FT-241-CRYSTALS-Many-to-choose-from-You-pick-/260897401407?pt=LH_DefaultDomain_0&hash=item3cbeb26a3f&_uhb=1#h
Hello group, we have the final and official confirmation we have been waiting for that we will be allowed access to the new 630m band from 01/01/2013! 5 W EIRP, with some exclusion zones that cover a
Hi Paul-Henrik, thanks for the direct link. I am curious to see the pi-tank design. Once I have decided the power output (will be based on the HV transformer I decide to use), I will calculate the ma
That is not the final schematic, this is one I drew as a starting point and there have been many changes (including a cathode resistor to provide some of the bias and a resistor with a few turns on i
Hello group, here is my prototype, 6AG7/807, crystal controlled, 25 W output, CW transmitter. Can't wait until the 1st of January to try it out on air! http://people.physics.anu.edu.au/~dxt103/valves
Hello LF/MF group, I though this may be of interest to those what would like to build the simplest transmitter possible for MF. I found these cheap crystals on eBay: http://www.ebay.com.au/itm/2-PCS-
Hi Roger, I checked the manual and it seems the antenna analyser produces +13 dBm (20 mW) on a 50 ohm load. The dominant type of geological formation under the soil is shale. The soil is not very dee
The noise floor is variable (over time) and the noise in WSPR S/N is calculated on a 2500 Hz window that may contain all sorts of RF garbage that come and go and will influence the noise calculation.
Buongiorno Mauro, I had the same problem with spots not appearing in the WSPR database. The spots started to appear once I put my callsign and QTH locator in the Setup -> Options (F2) menu. 73, Dimit
Hi Rik, I will try an unterminated dipole next. The weather has been really hot in the past few weeks here and the ground is probably drier than usual. My block of land is a bit hilly, so in fact it
Hello group, here is a quick test I did on 475 kHz, using some wires laying on the ground. I was really impressed by the signal strength but capturing the signal from my AA-30 antenna analyser surely
Hi Pete, It's always good to know there is a decent and reliable (and not expensive!) crystal seller! By the way, I noticed that since I posted this message, about half a dozen 15200 kHz crystals wer
Hi Pete, the problem with a .hex file is that it will contain my callsign, not yours! You will need to compile your own, however, if that's what stops you from making a transmitter or a general purpo
Hello group, I would like to increase the Q of my loading coil for 475 kHz. . It consists currently of a 20-litre plastic bucket with standard house 240V electrical wire (with PVC jacket). I measured
Hi Mal, The whole point of this design is that the output impedance is 50 ohm, therefore there is no need for impedance transformation! Try calculating the values for a 100 V, 100 W Class-E transmitt
Hi G, the gang down under doesn't like the top of the band - too noisy. The consensus so far is to switch back to 473.5 kc USB which results in an RX frequency of 475000R. 73, Dimitris
