Hi all, I was not able to find a reference text to eyeball myself, but Andrew ZL2BBJ has supplied the following references about measurements for losses for snow and glacial ice. -- Watt, "VLF Engine
To All from PA0SE dummy rely snip snip Andy says "Go back to the fundamental equations and calculate properly". A good advice but Andy did not follow it himself. snip snip I could not spot a computat
Thanks to James M0BMU for publishing the results of measurements of UR67 coaxial cable at 100 kHz. The very low Q readings are convincing evidence that using coaxial cable for LF inductive stubs woul
Good point. I have been breaking my mind about that for some while. But it seems to me that we take the inperfect ground into account already with the ground-loss resistance, so do we have to take it
Hi John, I tried to model just such an antenna a few weeks ago using Eznec.The idea was similar to yours to try to improve the top loading.However the configuration showed NO improvement over having
g3kev wrote: snip snip At this frequency with both antennas resonant on 136 khz on the same site, the induced rf from the small vertical into the larger one would distort any meaningful tests. The an
Bites in even more with a smaller antenna surely! What I meant to suggest was that a small antenna needs a great deal of applied power to achieve a radiated power of 1 watt. For most hams, it is impr
Hello LF group, I just want to share my last findings in the chase of "the missing dB's". Yesterday I changed the antenna ground plane and added 10x6 m chicken wire around the antenna base plus 12 ra
LF techniques covering every aspect have been documented over the years and while some purport to be inventing new methods they are really copying what has gone before. The broadcast industry has cov
G'day All, I have a question about something that has puzzled me for some time now. It concerns the procedure for giving signal reports. I understand the scale for readability - no problem. The probl
Sorry for being so useless but I can't find the three propagation links on your site. What am I missing (apart from two eyes and a brain :-) ? Probably a dictionary :) Bob ZL2CA
Hi All, When I first set up my 136 station I put up a Marconi "T" vertical ant. 15M high 30M long.The best ant. current I could get from my 400 watt amplifier was 1.8 amps.The measured ground /coil/c
Talbot Andrew wrote: snip snip Now for the interesting bit. When it came to measure the unloaded Q of each coil, the original one was a fair bit higher at Qu = 140, compared with the Litz wound coil
snip snip When November comes it will be an opportunity to try all the techniques currently available. It may well be that only the coherent modes get through, but it would also be great if we find w
Cliff K7RR, A US west coast site with a good mast would be ideal for listening out for ZL amateur signals. I'm sure we can activate ZL1WB and ZL6QH to see if we can cross the Pacific from down under.
Bob. I am sure that we could not get transmitting privileges on short notice, but we can listen while the West coast transmitter is down. Cliff K7RR Cliff, OK. I will see what we can set up in the wa
Hi all, A brief message to clear up the matter of carrier frequency of choice for ZL test transmissions for stateside. Amateur access in New Zealand is to the band 165 - 190 kHz. Most of the testing
Hi all, VTX3 is generally received at strength 9 in New Zealand. I understand the transmitter site is at the southern tip of India, so has rather good sea paths in many directions. 73, Bob
I use a home made passive phase-linear filter with a bandwidth of 30Hz and centre frequency of 1000Hz. It can pass up to 24 wpm without trouble (unfortunately the operator can't ...) The filter has f
