It's instructive to look at plots of the variation of wave impedance with distance from the source. These plots (acknowledgements to John Middleton and Marconi Insts, "Engineers EMC Workbook") http:/
Not online, but download, install and run-- http://www.aade.com/filter32/download.htm 73 Dave, ZL3FJ Anyone point me to an online tool for designing LPF's for say 5 7 or 9 pole Chebyshev's on LF or H
Glad I'm not the only one still waiting!! Thought 'the colonies' QTH may have had something to do with it-- perhaps not.... Dave, ZL3FJ (member since 1968) Actually I would simply like to see a copy
Warren I did one at national conference a few years back- there's a thread worth following using the history of LF experimentation and use- you can take this back right to the beginnings of radio-bot
Use one of these http://sharon.esrac.ele.tue.nl/mirrors/zl1bpu/micro/EXCITER/Index.htm to generate half the output frequency and double that -you may even get by with feeding the ~250 kHz into the st
As far as I know commercial morse services never tried to use the morse code for printing. SNIP............ Wildly OT- but in fact- machine printing morse systems predated most other variants of mach
Nothing official yet re VK operation- they have to wait till they get the word to start using the band and it seems a long time coming. I checked on this just yesterday with Steve Olney, VK2SRO. Not
Back in 1997 we temporarily activated a 400 foot ex AM broadcast mast at Kumara on the West Coast of the South Island. With an SSB signal at around 100 watts PEP into the mast, we had good LF propaga
Also been considering the ground loop option but for 136kHz- I can't recall any reference to this being tried anywhere by the amateur fraternity. If it has been tried, what were the results? Another
Andy What happens if you talk to in in binary? Same results? NMEA seems to often be almost an afterthought in some receivers and often odd things happen when using it... DaveB, NZ -- Original Message
Not directly relevant, given its size, but interesting for comparison purposes. ** ELF, VLF and LF radiation from a very large loop antenna with a mountain core Author: Barr, R. Ireland, W. Smith, M.
RogerAs well as pipework, there's a strong possibility for assisted signal levels from coupling into buried telephone cables. Longitudinal induced audio frequency signals can propagate literally mile
Thanks for the replies - some useful amps noted. I'd like to find something that could be used up to 500kHz but I guess an audio amp that performs up to that frequency is likely to be a rare beast. I
I've seen comments here from time to time about various audio power amps being used for low power tx purposes - any suggestions as to whats a useful one for 136 up to 500 kHz at the 5 watt level or t
Looking for recommendations and/or suggestions for an external (USB preferred) sound card for use with digital modes and SDR experiments, etc. Must have line level input capability and at least two i
A large common mode choke on the incoming line, just down stream towards the modem from the ETP (=NTE over there I guess) and again at the input to the modem did it for me. Using a single ADSL filter
Petr Use the T configuration as it will most likely keep the vertical section well away from earthed surroundings, which is most important for best performance. And use at least 0.5 metre spacing bet
John- re the noise problem. Were the poles with the 'noisy' down wires actually phone line poles or power line poles? Analysis you have done so far suggests the noise is mains related and sourced so
