Yes, there's a JFET on the other side. So far a BF245A. It works well. But the circuit consumes 3.5 mA. I thought it could be less. It is running at 5V DC and the xtal frequency is 1.8432 MHz. I loo
Am 15.07.2015 15:00, schrieb Andy Talbot: Assume you've tried putting an R||C in the source to bias the BF245 back a bit and still ensure oscillation? Yes, probably during you wrote that mail i have
Hello Markus, Thanks for your observation and article! :-) Most interesting. I can indeed confirm there were a number of cloud-cloud lightnings last night, up to 20 per minute were visible at times.
Hi Markus, Let's see what is possible. I'm trying to ground the far end of the inv-L to form a vertical loop. I guess that 20 A will be no problem at all but 100 A sound quite optimistic :-) Here is
Hi all, Yesterday the conds on MF were very good, low QRN levels and good propagation. On my remote grabber i'm running a slow scrolling spectrogram showing the whole 630m band over the last 20 hours
Hello Markus, VLF, A few minutes ago i've grounded the far end of my antenna with a massive wire. This would handle 100 A :-) See https://dl.dropboxusercontent.com/u/19882028/VLF/20150721_211722.jpg
Hi VLF, Now i continued with measurements of the new loop. I took 3 different capacitors in series and searched for the maximum antenna current for a fundamental frequency. I had and have no idea abo
Markus, Am 18.07.2015 06:50, schrieb Markus Vester: The screenshot http://df6nm.bplaced.net/VLF/spherics/dk7fc_VLF_150718_1326.jpg shows a number of narrow tweek-mode resonances at multiples of 1.72
Hi VLF, Today I've built a transformer to match the antenna to the PA. This is not the ideal solution for QRO / highest antenna currents but i like to idea of a galvanically decoupled antenna and TX.
Hello Andy, How is this possible? Your Loop points to SE, my loop also points to SE. But we are not in one line. Actually it would be best for us if our loops would point to NE. But i can receive you
Hi all, I had to spend 8 days in the hospital but now i'm back here and on the band(s). I removed the short-circuit on the far end of the antenna, i.e. switched back from loop to inv-L so i can take
Just FYI, i found that there was a certain correlation between transmitting and the arrival of the fire brigade (EMC issues)! When using a (linear) audio amp, nothing happend but the currents are sma
Hi Roman, Uuh, sounds good! I will be there, it's time to heat the LF coil! 73, Stefan Am 08.08.2015 19:27, schrieb Roman: GD Genossen LFers! Russian informed abt Activity Day: http://136.su/index.ph
Hello Bruce, Soon the sunset will be on your side. There are a few stations active. Condx seem to be rather poor. What about TX stations on your side? It would be nice to have a RX-challenge :-) 73,
Hi all, I'll give it a try in CW soon. Later then in DFCW. Hope the RIG is still running... 73, Stefan Am 09.08.2015 12:19, schrieb DK1IS: Hello Mike, it seems today we canīt make it directly in real
Am 10.08.2015 14:09, schrieb Chris Wilson: 10 August 2015 Is there a way of protecting a typical MOSFET driver IC from being taken out by a MOSFET failure in a Class E LF amp? Hi Chris, It can be hel
I agree, it was a very goof idea to make this activity day and it was a big fun. A pity that we don't use the LF band more often. We should try more activity days, in shorter intervalls :-) I want to
Hi all, My remote MF system is down at the moment, for doing some upgrades and improvements. I'm replacing a DC/DC converter which supplies the Raspi with a constant 5V voltage. So far i used a LM259
Hi MF, Last weekend there was some activity by DL1HTY on 630m. They were active /p. I didn't expect so much from what they said before the activity but then i even worked them is CW. They had a relat
Hi LF, I'm back there is WSPR-15 for some time. The power is reduced by 4 dB, unfortunately. Maybe someone can catch a trace anyway :-) 73, Stefan/DK7FC
