Yes, I have seen it before. That rule of thumb is near resonance with about 500 ohms of reactance (Xc = -j500.5 and Xl = +j471.2 ohms). If you replace 1 metre with 37 inches, the error will be less t
Hi Stefan, Clint Turner http://ka7oei.com/ has interesting information on his "optical communications page" http://modulatedlight.org/optical_comms/optical_index.html. Linear's design note DN399 abou
Marco, I too re-read a couple of pre-2000 messages and got into the nostalgic mood. Regarding John Rabson, he has not passed, he moved to F-land. He posted a message a few minutes ago! Maybe you were
Yes Peter, I remember that moment very well! I also remember your comment about shooting your Champagne cork in the wrong direction (I think you said it flew to your neighbour's balcony?). 73 Johan S
Tracey, I use a small butane powered blow torch when soldering antenna wires outdoors, heating the solder joint directly with the flame. Works great! 73 Johan SM6LKM --
*_TEST TRANSMISSION WITH GRIMETON RADIO/SAQ ON 17.2 KHZ_* Because of the missing Christmas Eve transmission we will have a test transmission on *Tuesday* *10th, 2012 at 13:30 UTC.* * * There will onl
Hi Wolf, LF how much dynamic range is needed in a dreamer's band receiver? The typical 9kHz signals are very small compared to the noise level so there is plenty of "natural dither". Do you think tha
Hi Daniele, you may get some inspiration from LZ1AQ's loop amplifier design. http://www.lz1aq.signacor.com/docs/wsml/wideband-active-sm-loop-antenna.htm 73 Johan SM6LKM -- Daniele Tincani wrote:
Hi Peter, maybe it is caused by some sudden interaction between the thunder clouds and the ionosphere? Rapid transport of electric charge through sprites and jets? Just a wild guess... 73 Johan SM6LK
Stefan, Jim is right as always. Ferrite is unusable in VFO inductors. I just wanted to add that Micrometals (== Amidon) Txx-6 has a slightly lower temperature coefficient than Txx-2. I have built suc
Stefan Schäfer skrev 2012-09-21 00:04: Hi Stefan, I'd guess it is the power section of a PWM AM modulator for one of your switching QRO amplifiers? 73 Johan SM6LKM
Very nice graph Peter! It is interesting to see the very abrupt signal drop in the morning, and how well it correlates to sunrise, and compare it to the irregular return in the evening. 73 Johan SM6L
Hi Stefan, in many cases it is perfectly OK to have a singly terminated transmission line. If your RG58 coax is terminated with 50+j0 ohms at the end, your active antenna output stage will see 50+j0
It all makes sense Jim, except for the IC-706 in-Volvo-stallation. How and why did you use iron wool to accomplish that!!? :-) 73 de Johan SM6LKM -- [...] [...]
Edgar, QRSS-VD is widely used in the HF QRSS community, it can average over many message repetitions to improve S/N. You can find it here: http://www.swharden.com/blog/ 73 Johan SM6LKM -- edgar wrote
