hi Chris ! when we started to do 136 in the late 90s, i had a 100 ft tower with umbrella type tophat sitting on 1.5 inch Teflon blocks. 8000 pounds of steel winched with hydraulic tools onto it. load
hi ! i think the question was about the LPF , not the tank circuit. LPF yes, if its 50 Ohms to 50 Ohms, same for all types of RF-generator. If components like feed lines and generator and load impeda
hi ! I found an online calculator that allows to set the Q and the impedance for a tank circuit. http://people.physics.anu.edu.au/~dxt103/calculators/pi_tank.php most others are only giving a resonan
Hi Chris and Clemens, surely a Pi-circuit provides a much greater selectivity than an ordinary push-pull amp by itself. Which resembles a frequency multiplier. If one does not need many bands to cate
good morning ! a current transformer with ferrites of unknown origin and virtues is a very risky thing. As these cores are widely available on swapmeets its a lure to use them. But they can be tested
Hello All ! Are there any „grabber“-stations in Europe that have a real-time display accessible via internet ? Will start my MF-beacon DI2BJ on 505.030 kHz by tmw with regular CW. Reports
Hi ! Is there any experience around about using stainless steel wires for toploads or feeders versus copper ? As to my knowledge there is a certain amount of rf current penetrating into the conductor
Hi folks ! I improved the ground system of the DI2BJ beacon on 505,030 kHz. I used a pipe into a deep water well for extra ground, measured some serious RF-current going into the wire connecting the
Hello group ! I found that almost all amp configurations generate harmonics. In case of a homebrewed HF amp, with a push –pull design, I had to build hi-pass filters with a resistive terminatio
Hello group ! I am not an expert with WSPR at all. But I followed the discussion regarding false detection of calls thru the database. To my understanding the WSPR operator has NO way to really find
Hi Scott ! Interesting about the signal from DCF in Germany. That transmitter is about 50 miles east of me. But on LF almost no chance for VE7. Are You doing any on 500 kcs ? That band is more of a c
Hi LF/MF gang ! Best bet is to use semiconductors or tubes that outlive the power supply used ! Americans call this the NFA approach. It keeps stuff out of trouble. 73 de wolf
Hello Group ! Hny to everyone on board J. DI2BJ will be active from 1545z thru sundown on 505.030 kc today. This is to provide observations thru the decay of D and E layers at the transmitter locatio
Hi Rik ! Explicitly no QSOs are permitted for DI-experimental stations. We are not part of the amateur radio service legally. But we hope for better times to arrive J 73 de wolf df2py/di2bj
No worries folks! I`ll put a beacon on the air on the 9kc band. Takes two more weeks. Other than on 500kcs, where we are denied QSOs by our FCC, we can do as we like on the 9kc band, if we pi ck up t
