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Hi Stefan - the loop in use here is pretty much the same as I used in Oklahoma -though far less successful due to ground/topo/geomag and just plain distance (well those are my excuses)
Total length is around 182 metres (if I remember) with some 25m verticals and 3m above ground on the lower horizontal run
13:2 ratio transformer 3 x 290/77 individually wrapped and stacked (stays pretty cool) , 1nF vaccum remotely tuned with some 5 parallel sangamo or similar transmittting caps (mostly G3s) for a total of around 10nF ( cant recall without my notes) for current
division and thermal stability.
Total power available at 100% is around 1.4kW from a Decca 5501 and 300ft of LMR400 - max current is up to 40Amps with a mix of #4 or #6 TFFN stranded copper or parallel sections mostly for mechanical survivabilty as is is strung over branches but free
spans still exist, not for Rtot losses where other “wider” less lossy materials would be more effective but wouldnt survive the first major Alaskan storm. Ive tried them - im typically “guying” a lot of the taller Birch trees :-)
By calcs I “should” be able to reach some 3W EIRP or so but in reality the local ground here just doesnt perform as the excellent “flat” non obstructed views of Oklahoma where we could hit ZL on qrss or other stepped modes for some periods of the year
- Its been a pretty rare occurence from here. The close in mountains on some headings really doesnt help either....
I can run any non linear mode but have run and qso’s in WOLF in the past without any moans
Laurence KL7L in KH6
RR Laurence,
Your loop for 137 kHz, what are the dimensions? What type of wire do you use? Do you reach 1W with the loop as well? And at which power level and antenna current?
73, Stefan
Am 30.03.2019 17:18, schrieb Laurence KL7 L:
Mng Stefan - yes I still have 1W EIRP on 137 from a nested Marconi or Ashlock loop, tho loop fires East/West - and yes to VLF too with improvements to the sub 10kHz s/n over the past couple if years -The pc was older than 10 years....and ill have to buy
one when I get back home
Paths from Alaska East to East coast are pretty difficult tho not impossible given past rx on 75kHz and lower - can be easier over the Pole around mid winter
Good to see VK4YB making the trip on 137 wspr to here overnight at good strength - - - nothing on JT9 screen pre dawn
73
Aloha
Laurence KL7L/KH6
Hi Laurence,
RR abt EbNaut. A short EbNaut message, like a callsign, transmitted in 8K19A should be no problem unless your PC isn't older than 10 years :-)
BTW are you still QRV on 137 kHz, i.e. can you transmit?
I guess that Jay would be able to decode you...
And is your VLF grabber still ready? We have never been successful over that path, even with the kite experiments. But now i have that earth loop and it looks like i can reach a similar signal strength, even stronger! And, with that loop i can transmit at night
whereas this was not possible with the 300m kite. There could be much better chances at night. Some day it may be worth a try...
73, Stefan
Am 30.03.2019 01:08, schrieb Laurence KL7 L:
I agree Stefan! CGM has a very distinctive analogue curve and is a regular into AK
I made it a goal to get EbNaut running this winter and got so far but pc processing performance was just not good enough - the pps etc is fine but as my last tower just died I dont have any excuses except cash to get a decent machine now -
aloha
Very nice! Good old analog modes. I remember...
73, Stefan
Am 29.03.2019 22:29, schrieb Laurence KL7 L:
Good to see JA1CGM signature signal here into Maui on a not so quiet night. Eprobe SDRIQ at off 6th floor balcony
Alaska receivers will be off line until I fix up a new PC or replace the CPU
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