[Lowfer] W7IUV in EN90xn

[N1BUG]

When Ward and Ron were both transmitting on 2200m, one would often 
peak here when the other was in a dip. Other times the peaks would 
occur at the same times. On some nights Ron would peak stronger than 
Ward. Other nights it was the opposite.

Another thing I have noticed is what at first glance appears to be 
path non-reciprocity. Typically there is about 6 dB difference 
between reports I give K3RWR and those he gives me. But, it is not 
uncommon to see that difference almost vanish or increase to 15 dB 
or more for relatively short periods. Perhaps this would not happen 
if at each end one antenna was being used for both transmitting and 
receiving. At least at my end that is not the case. It may be that 
my receive antenna has a peak response at a different 
takeoff/arrival angle than my transmitting antenna.

There is clearly a great deal of variability in propagation. Based 
on my own observations I am far from convinced that comparing signal 
strength or SNR of two stations on different paths (even paths that 
are only slightly different) is of much value other than as a curiosity.

Paul N1BUG



On 03/07/2018 02:23 PM, Ward K7PO via Lowfer wrote:
> Guys,
> 
> Here's my $.02 worth. When Ron and I tried the head to head tests, we saw variations that didn't make a lot
> of sense some days. Even running the same power (identical amps built by the same guy, HI), we saw 6-10 db
> differences. Ron and I are ~50 miles apart, much closer than Larry and I. The only trend I noticed with our
> testing was that Ron was consistently stronger in the 1500 to 2000 km range (AZ to IUV for example), but I
> was usually stronger on the 3000+ km paths, (for example KL7L). Running the same power, there were many times
> I'd be decoded in VK (630m) and Ron would not. Our conclusion at the time was a difference in take off angle.
> If true, and taking into account our geographical difference, and my gut feeling about WSPR's non linear reports
> especially in the lower signal levels, I don't see where we can make any real correlation between stations, except
> in very broad terms. As for my power level, I show 5W(because that's what the U3S lets me report), but I believe
> it's closer to 4W ERP. I don't know if Larry is using ERP or EIRP for his reporting.
> 
> Another interesting thing in the numbers is Larry shows a 2 db spread between 0902Z and 0942Z. During roughly
> the same time period, 0904Z to 0944Z, XXP shows an 11 db spread in reports. What's going on there? It would
> appear that Larry's path was much more stable than XXP's during that small window. Going back just a few minutes
> for XXP, the spread is even greater, with a -11 spot at 0856Z.
> 
> 
> Ward K7PO/WH2XXP