right Your knowledge of the mind attitude of the Windows designers is very approximate. They never thought, never for a while, that God was before them.... Windows inevitabley involves several panes
Dear James and LF Group, Your perception of being limited to some 100 Hz of overall bandwidth for transcontinental LF work is unlikely to be the case in other continents. Down here we have 165 - 190
Jim, Your statement All this means that the spectrum available for a group of transmitting stations participating in "transatlantic tests" is probably only 100Hz. assumes that the EU band plan can no
Alberto Hi all, which would you all prefer as a way to frequency-shift your TX ? With frequency shift I mean many steps, separated by a fraction of an Hertz. The first two possibilities that come to
Dear LF Group, Thanks to Jim M0BMU for generating a good discussion paper. I have a few comments: I've taken the liberty of changing a word in the title from transatlantic to transcontinental. I'm do
Larry, You have found an oddball way of getting unwanted local audio. I have been having a bit of a problem receiving LF signals with ARGO, I am not able to see the signals due to interference. I hav
No messages from this reflector - is it working properly, or in quarantine for Foot and Mouth :-( Andy 'JNT Andy, Just as a precaution, please run your files through a disinfectant bath before forwar
Jim, Dear LF Group, Since somehow or another I seem to have gained the most experience of any UK amateur of successfully transmitting and receiving "Wolf" mode signals, I could put together a short t
Hi all, A further point about frame loop (magnetic) receiving performance is that the near field is generally smaller than for a similar dimensioned (active) (electric) vertical whip antenna. If neig
Steve, Good pics on sideband roll-off in the modulator. Note that any practical power amplifier would regenerate some sidebands at a significantly higher level than they were at the output of a BPSK
Rik, Very interesting on the three types of spectra: So far I 'played' with 3 types of modulation : real BPSK, PSK (amplitudes enveloped) and what I call 'soft' PSK (gradual phase transitions instead
Alan, I comment on one part of your reply: To Bob, I think the efficiency of the PA is only high if you calculate the input power to the 'total' output power (wideband), the harmonic power doesnt 'im
Alan, OK on the absorption arm of a diplexer: Hi all, Dick PA0SE, remarked some time ago that a diplexer with an absorbtive load for the unwanted harmonics might help to tame some of the ' FET-eating
Jim and others, Some rigs have DDS sidetone, including the TS-850. I modified my TS-850 so that sidetone is available from the rear panel, and is present whenever CW mode is selected. I originally wa
Hi all, One way of generating a frequency for LF transmitting is to "divide by 100" from an HF band. In New Zealand we work around 181.4 kHz, which conveniently means 100 times turns up within the 17
Dick and others, I have made several PAs for 180 kHz, mostly with bipolar power transistors. Down this way we also have SSB nets, so at least historically, most PAs were designed for similar type of
Steve, The 3500 km path is still in good shape as of last night. Condx a little better than my last receive attempt but nowhere as good as they will be in the fall! I was impressed by your Argo scree
Hi all, Andy's information is also my recollection of the meaning of LUF: Seem to remember reading that LUF is a calculation based on D layer absorbtion. Propagation predictions software giving LUF u
Jim and others, The graphs in Terman show only a modest 3-4 dB variation in signal level over the sunspot cycle - but what they don't show is what the signal-to-noise ratio was. The high noise level
To all, Thanks to Dick PA0SE for doing further tests. Replacing the antenna with a increased capacitance from a vacuum variable has lower losses than the "antenna circuit" but it is a reasonable appr
