Dear Jim. Thanks a lot for coment. As was seen some time ago with the experimental "Hendrixizer" clipping feature added to Jason, non-linear processing of the signal can certainly be an improvement u
Hi, Claudio. I have just finished a new release of glfer, a Linux application combining a spectrogram viewer and a QRSS/DFCW keyer. As You are working in computer signal processing it seems result of
Hi, Claudio and Group. Regarding the hardware requirements, for the basic spectrogram and TX keying functions I have used a Pentium 133 and it worked fine; the other spectral estimators could need mo
Hi, Claudio and Group. Dear LF Group, I have just finished a new release of glfer, a Linux application combining a spectrogram viewer and a QRSS/DFCW keyer. As usual, the code is released as open sou
Hi, Alan and Group. If maybe you are screened from some of the ground wave then there could be interesting plots made. At my location of approx. 700kms from DCF39 I get get a steady level during the
Hi, Group. With reference to the proposal that RSGB put forward for consideration of an amateur allocation at or around 500kHz, It should be wonderfull! 136 kHz is too low and 1.8 MHz is too high...
Hi Mal and Group. and have found the vertical a lot better and easier to tame, easy to match using a series inductor and tuned against an insulated ground radial system to match 50 ohms, and manageab
Hi, Group. 3. Put a suitable light bulb in series. Measure the brightness with a light meter, then see how much DC or mains frequency current it takes to produce the same brightness. More easy way: t
Hi, Jay. Bill Ashlock's measurements have shown that the loop needs to be at least 5 - 6 feet off the ground. He's currently running a 1/2" copper tubing loop. If you're interested, I'm sure he can f
Hi, Bill. My present loop is constructed from .63" OD copper pipe. The figure of merit for 50/50 loop antennas is the total AC resistance (Rac), including ground losses, and this one measures under 0
Hi, Mike and Group. Hi Alex, We use vertical loops here. The trees don't affect them much. I can walk up to my loop and watch the RF current meter and not see any change until I get closer than 1 foo
Hi, Group. You sir, are absolutely WRONG! A spent 100s of hours on my vertical antennas before changing over to loops. It seems to me a loop (if wire diameter is large) may be bit better then vertica
When C decreases from 10 uF to 1 uF voltage increases from 10 V to 100 V So energy E=C*U^2/2 changes from 1e-5*10*10/2=0.5e-3 J to 1e-6*100*100/2= 0.5e-2 J. Where did extra energy come from? To drain
Here is another conundrum along similar lines - you have two identical, loss-free 1uF capacitors, one is charged to 10V, the other is discharged. You then connect the two in parallel so the total C i
Will a charged air variable capacitor try to turn itself towards the maximum setting? :-) Yes, of cose! Remember electrostatic voltmeter. It is a variable capasitor with pointer and elastic someone (
Hi, Andrew and Group. An oil filled capacitor consists of two plates separated by a dielectric made of oil with a dielectric constant of 10. The capacitance is 10uF and it is charged to 10V. The oil
Hi, Group. There is some info from RU6LA. Last night Ed has 'M' copy G3AQC on 73 kHz. He used 1500 m Baveradge antenna. Also he had some problem with TX antenna due to strong snow. Hope TX ANT will b
Some addition: Realy he had mesure earth resistance plus enviroment loss resistance. Also leak in isolators also yelds a loss. Enviroment loss can became grater when dielectric enviroment (say dry wo
Hi, Mal and Group. Dick has indicated that Earth Resistance gets higher when the ground is wet. That seems strange and contrary to accepted theory. Realy he had mesure earth resistance plus enviromen
Hi, Dave and Group. 1 MW sounds interesting for 5W ERP. Is he using a CFA? If anybody use CFA he realy need 1 MW TX for 5 W ERP. hi... hi... hi... With normal antenna 5 or 10 kW seems to be adequate.
