[Lf] 136 kHz propagation

[Andre' Kesteloot]

Rik Strobbe wrote:

> Hello group,
>
> I am not sure that propagation on 137kHz is much correlated to 1.8 or 3.5MHz.
> On those bands (160m and 80m) DX propagation is mainly via reflection at
> the F2 layer and the signals are attenuated by the D (and eventually E)
> layer. During solar minimum the ionisation of the D and E layer is very
> weak while the F2 layer ionisation remains strong enough for these low
> frequencies.
> When I understand some articles about propagation on LF well, DX
> propagation is via E layer reflection (in some seldom cases even D-layer
> reflection). This would explain that QSO's up to 2000km (1 hop e-layer
> reflection) are made with rather low ERP (few 10mW) while transatlantic
> propagation (2 hops or more) require at least a few 100mW.
> Question is : will the E layer ionisation be strong enough at soloar minimum ?
> The answer will be known in a few years ...
>
> 73, Rik  ON7YD
>
> At 11:05 15/05/01 -0700, you wrote:
> >
> >Hi Chris,
> >Terman's graphs show that T/A sig levels are strongest during peaks of the
> >solar cycle. Whereas the correlation that Laurie described is T/A success
> >when sunspot numbers are low.
> >My guess is that both are probably true, i.e. on average T/A signal levels
> >are better during the active part of the cycle, but conversely weak signals
> >are more likely to be disrupted during the active part.
> >We will probably find that at the low point of the cycle chances of getting
> >across are worse but consistently worse, if you follow me.
> >73, John
> >