Re: LF: WSPR 15 tonite

[Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>]

Hello John,

Well, don't think it is as easy as on HF. We can make the same distances BUT on HF we're talking about SSB or CW and on LF we're talking about DFCW-180 or so.
In WSPR-2 you can be detected at the antipodes with a few meters of wire thrown in the greenery and 5W by a QRP rig. On LF you need really BIG antennas and have to spend a lot of effort to reduce the losses and increase the radiation resistance. Furthermore you have to deal with several (sometimes dozens) of kV on the antenna. And you have (at least a bit) to understand what you're doing, while you can press the "auto-tune" button on modern HF rigs... That makes LF/MF a special community with challenging things to do :-)
I guess a "average" HF amateur can easily make > 10000 km in SSB while a well equipped amateur on LF struggles with WSPR-15 to make a > 3000 km range.

I'm looking forward to see your first results on the band! Will you intend to TX on the bands in the near future?

Still, what type and RX site are you going to use?

73, Stefan/DK7FC

Am 21.10.2013 05:05, schrieb John Lutz:

Stefan,

 

Thanks for the quick reply and the encouragement regarding my choice of the IDC-136.  It is good to know others are using it with success.  It sounds like modifications to the receiver itself aren't really necessary.

 

I have to admit that I'm really surprised by the distances being achieved at 136 KHz.  I would have expected that a couple hundred miles would be the upper limit, and that even that far would be pretty infrequent.  After looking at the WSPRNet database, I can see that I was very mistaken about that.

 

I see lots of reception reports from you for G3XKR (940km), R7NT (2234 km), 4X1RF (2850 km), and many other distant stations.  I would never have thought this possible!   :-)

 

Regarding my antenna, I will initially use a 7.25 meter ground-mounted vertical.  Normally, I use it for 30-meter operation.  I am in the process of constructing a PA0RDT mini-whip.  I understand that "active" antennas of this type are fairly popular of LF/VLF work.

 

Again, thank you for taking time to respond to my email.  I hope to be WSPRNet active very soon.

 

73,

 

John / N9JL