LF: 136kHz report

Andre' Kesteloot akestelo@bellatlantic.net
Mon, 01 Feb 1999 19:34:33 -0500

John G4GVC wrote:

> [...]
> On a different subject, I wonder if the US team have any plans to try a big,
> wire receive antenna for the next Transatlantic tests? I know this could
> involve a lot of work, especially if the weather is bad, and would need to
> be carefully sited to minimise man-made noise and QRM pickup, but it might
> give very different results to the small/active antennas previously used. I
> think I am right in saying that practically all of the "successful" UK LF
> operators use large wire antennas for receive, and this is probably true for
> most stations working DX from the other countries too. I am no expert on
> small loops and whips, but I have used them a fair bit (some of you will
> remember my series of mobile RX tests last year and the operation at Woburn)
> and am personally convinced that there are many weak signals I can hear on
> my big antenna which are inaudible on the small loop, even when it is well
> away from the inverted-L. Most of us use large "T" or "inv-L" antennas for
> receive, although considerable success has has also been achieved with
> single or phased large delta-loop configurations by Steve, Lech, Peter and
> particularly Derek, amongst others. Conversely, there are several stations
> on the band using small active RX antennas who seem to have great difficulty
> hearing DX at all! Obviously comparative results depend on levels of noise
> and interference pickup by each antenna and the overload immunity of the
> receiver, but I do feel it would be worth considering the use of a large
> antenna if it's practical.
>  Regards  John G4GVC near Leicester, IO92JP

John G4GVC, and the rest of the rsgb_lf gang, read the following message from
Bob Bruninga WB4APR:

"Did you know that the 1200 foot high LF transmit antennas in Annapolis are
standing idle with nothing attached?  These were originally tuned to 38
KHz and something else?  I can get you to the feed point and the caretaker
would be happy to radiate.. [...]Reading in the last newsletter, Annapolis sure
seems closer than NC and has orders of magnitude antenna capability.  All these
antennas are scheduled to be demolished next year, so time is relatively short.

de WB4APR, Bob

Annapolis, Maryland, is a former US Navy site for LF transmissions.
Hence, you may well appreciate that we are indeed getting ready to use that
vertical 1200 ft. long wire  :-)
The problems of course are numerous: for instance, how to couple to the antenna
without being killed by static electric charges, etc...
Maybe a tube (valve) may be better as the first stage
We will let you know as soon as we have picked up a date for the field trip to
Andre'  N4ICK