[NLRS] The other end of the spectrum

[W0WOI at aol.com]

Technology:  Hams' Experimental VLF Signals Heard in the UK, Europe
In what's believed to be a "first," a very low frequency (VLF) signal from 
a  ham radio experimenter in New York was heard across the Atlantic. Bob 
Raide,  W2ZM, was transmitting on 29.499 kHz under a Part 5 Experimental 
license,  WH2XBA/1. His very slow-speed (QRSS) CW signal was initially detected in 
the UK  just before 0000 UTC on March 3 by Paul Nicholson, an SWL, and 
later by Mike  Dennison, G3XDV, and Markus Vester, DK6NM, in Germany. Nicholson 
also copied a  29.501 kHz transmission from Dex McIntyre, W4DEX, in North 
Carolina, operating  as WH2XBA/4.      
The plate tank circuit in the WH2XBA/1 VLF transmitter.  [Bob Raide, W2ZM, 
photo] 
"In recent weeks a number of amateur tests have been running from the USA 
to  Europe around 74 kHz and at 29.499 kHz using several hundred watts to 
large  antennas," _blogged_ (http://g3xbm-qrp.blogspot.com/)  Roger Lapthorn, 
G3XBM. He said  that signals on 74 kHz were "well copied," but that "the 
surprise" was detecting  the 29.499 kHz signal. "As far as I know, these 29.499 
kHz VLF signals are the  first amateur VLF [transmissions] to span the 
Atlantic -- fantastic results by  well-equipped stations using suitable receivers 
and good software."  
Warren Ziegler, K2ORS, who is on the Experimental license as WH2XBA/2, told 
 ARRL that he and several other radio amateurs have obtained Part 5 
licenses to  experiment on 500 kHz and on 137 kHz. Ziegler, who has been a 
participant in the  _ARRL-sponsored  experimental operations_ 
(http://www.500kc.com/)  on 500 kHz as WD2XSH/23, said Raide wanted to be the  first to span the 
Atlantic on VLF, which he defined as between 3 kHz and 30 kHz,  so Ziegler 
applied for and received the WH2XBA Experimental grant, and included  Raide 
and four others on the license.      
The loading coil for the WH2XBA/1 VLF antenna system.  [Bob Raide, W2ZM, 
photo] 
"I was ready," Raide told ARRL. His transmitter has a 3CX3000A7 tube in the 
 final, running grounded grid and generating 800 W. The effective isotropic 
 radiated power (EIRP), however, was estimated to be approximately 1 mW. To 
 operate on 10,000 meters, Raide has a 90 foot vertical antenna using a  
reconfigured Zepp, fed via a huge loading coil that is 4 feet tall, more than 
1  foot across and comprised of some 2000 feet of #14 wire. He employs a few 
 thousand feet of "chicken wire" for his radial system.  
The transmission consisted of "XBA" sent at a rate of 120 seconds (2 
minutes)  per dot and 360 seconds (6 minutes) per dash of CW. In the UK Nicholson 
copied  the signal on software using a PC sound card with a preamplifier 
ahead of it.  His antenna is a pair of orthogonal loops, each 20 meters square, 
at ground  level, transformer coupled to the preamplifier. Read _more_ 
(http://www.arrl.org/news/hams-experimental-vlf-signals-heard-in-the-uk-europe) 
.  -- Thanks to Warren Ziegler, K2ORS, Bob  Raide, W2ZM, and Joe Craig, 
VO1NA  < From March 14, 2014 ARRL Newsletter  >