Today saw another 200m of wire added to the long wire antenna. Its impedance dips to a minimum of 70 ohms at about 170kHz corresponding to a free-space quarter wavelength of 440m which is somewhat le
Hi Paul, Very nice! I suggest to choose a frequency of 137.5 kHz +- 50 Hz, because this is the range for OPDS receiving stations using DF6NMs tool/decoder. There we can directly use the exportet txt
LF, Stefan wrote :- I suggest to choose a frequency of 137.5 kHz +- 50 Hz. Do you realise that this is already the established center frequency for Opera & WSPR ?? Be best to choose another. -- 73, d
Am 08.03.2016 11:49, schrieb Gary - G4WGT: LF, Stefan wrote :- I suggest to choose a frequency of 137.5 kHz +- 50 Hz. Do you realise that this is already the established center frequency for Opera &
I rebuilt the PA with bifilar wound choke feeding DC to the push-pull drains and the primary winding on the toroid has no center tap. With no load and with 50 ohms directly on the secondary the drain
Hi Paul, Am 10.03.2016 23:29, schrieb Paul Nicholson: The coils of the T filter wound on ferrite toroids get very hot very quickly. It's the ferrite producing the heat not the wire. I must have the w
Thanks Tobias and Stefan! I ordered a few T130-2 and a couple of T200-2, should arrive in time for next weekend. Meanwhile, I rebuilt the filter using air cored coils and it works great. A lovely 200
Hi Paul, Mix #2 (µi=10) is certainly the right choice for a LPF as Stefan and Tobias have pointed out. I use it too for my MW PA. The manufacturer on http://www.id-elektronik.de/en/index.htm => click
Hi Paul, 15:15 UTC on 136.175 kHz, i bet this was your signal! ;-) Am 12.03.2016 08:48, schrieb Paul Nicholson: Meanwhile, I rebuilt the filter using air cored coils and it works great. A lovely 200W
Could be? Carrier on air 136.175 kHz intermittent since 16:40, continuous since 16:54 and later will move to a frequency in the OPDS band for some EbNaut. 236W DC input. Instant LF coupling transfor
That reminds me, I need to stock up a bit with FKP caps! I haven't measured the antenna current, I'll have to rig something up to measure that. It's probably 2 or 3 amps. The wire is about 500m but
Could be? Carrier on air 136.175 kHz intermittent since 16:40, continuous since 16:54 and later will move to a frequency in the OPDS band for some EbNaut. Il giorno sab 12 mar 2016 alle 18:34 Paul N
hello Paul, my LF receiver is active and it is recording audio for Ebnaut-RX. GL. 73 and good weekend to all group. Domenico, iz7slz Il giorno sab 12 mar 2016 alle 19:58 Domenico IZ7SLZ <iz7slz.domen
Looking at Gary's page http://myweb.tiscali.co.uk/wgtaylor/grabber2.html My signal shows up well on grab 2 but grab 3 there are some glitches which I can't account for. And scrolling down to grab 5 t
Hi Paul, Yes, I noticed the "blips" on the qrs120 grab, I have no idea what or why. The sig on 8270Hz is local test, just from the DDS VFO to a short wire. 73, de Gary - G4WGT MF-LF-VLF Grabber : htt
...recording 137.45 to 137.55 kHz here as well. With 4 m effective height, radiation resistance for vertical polarisation would be around 5 milliohm, so no real risk of breaking ERP rules (yet ;-). I
Looks like I'm getting some carrier on 137455 but it's not very strong here (about 12 dB in 0.438 mHz). Stefan's opds spectrogram is plagued by a set of spurs in that vicinity. Maybe 137465 looks a b
Am 12.03.2016 20:09, schrieb Paul Nicholson: So maybe I will try Frequency: 137455.00000 Hz Coding: 8K19A Chars: 12 Symbols: 848 at 2 seconds Duration: 1696 seconds, 00:28:16.00 Repeat: Each hour, XX
The transmitter is running happily so I will leave it on for a few more hours. Frequency: 137455.00000 Hz Coding: 8K19A Chars: 12 Symbols: 848 at 2 seconds Duration: 1696 seconds, 00:28:16.00 Repeat:
Repeats 20:00 to 08:00 completed and closed down at 08:30 Frequency: 137455.00000 Hz Coding: 8K19A Chars: 12 Symbols: 848 at 2 seconds Duration: 1696 seconds, 00:28:16.00 -- Paul Nicholson --
