[Elecraft] K3 receive on .474.2 kHz

[Eric NO3M]

Not unlike the mystique of 160M propagation at times, 630M is much more 
complex than just reducing propagation paths to primarily ground wave.  
This winter, while rather anemic in respect to overall propagation, has 
presented some interesting communication opportunities.  On at least two 
occasions, there have  been viable openings between here (WPA) and Texas 
where JT9 QSOs were successfully completed at mid-day running less than 
10W ERP on both sides.  The suspected path is via D-layer due to less 
absorption than normal, though, absorption probably still being high.  
The QSOs are documented here:

http://njdtechnologies.net/a-midday-surprise-jt9-wg2xjm-wg2xiq/
http://njdtechnologies.net/the-daytime-surprises-on-630-meters-continue/

Some basic discussion on MF propagation:
http://en.wikipedia.org/wiki/Medium_frequency#Propagation

and if you really want some thought provoking reading on 630M 
propagation (incl. effects of moon phase, equinoxes, etc.), go to the 
600M mailing list archives:

http://w7ekb.com/pipermail/600mrg_w7ekb.com/

and search for posts by "James Hollander" (W5EST), who has been 
exploring and discussing various propagation phenomena based on the 
experimental activity on the band.  Some examples ("Quartile Method of 
Characterizing 630m Propagation Paths"):

http://w7ekb.com/pipermail/600mrg_w7ekb.com/2015-February/007945.html
http://w7ekb.com/pipermail/600mrg_w7ekb.com/2015-February/007946.html
http://w7ekb.com/pipermail/600mrg_w7ekb.com/2015-February/007947.html
http://w7ekb.com/pipermail/600mrg_w7ekb.com/2015-February/007948.html

On another note, Larry, W7IUV, is performing comparative testing of 
various probe (PA0RDT, W1VD) and eventually Flag/Loop style RX antennas 
against a 600ft BOG as the standard.  Information can be followed by 
going to the above 600M mailing list archive as well.

73 Eric NO3M / WG2XJM (630M Part-5 op)




On 02/23/2015 01:01 PM, Jim Brown wrote:
> On Mon,2/23/2015 12:10 AM, Edward R Cole wrote:
>> Most propagation is ground wave which does not extend as far as HF.  
>> Best propagation is in winter and at night when a little sky wave is 
>> seen. 
>
> A clarification. The strength of ground wave propagation increases 
> with decreasing frequency. The FCC Rules for the AM broadcast band 
> include a family of graphs for ground wave in groups of a few channels 
> to cover the band. Ground wave distances on the low end of the band 
> are MUCH greater than on the high end.
>
> 73, Jim K9YC
> ______________________________________________________________