Hi All,

Can anyone suggest the minimum S/N ratio required for a viable QSO using other transmission modes.

For example, I’d like to be able to directly equate WSPR S/N with that required for an AM, SSB. CW, RTTY, PSK or SSTV QSO.

I seem to remember that someone stated the minimum S/N ratio for CW with an experienced operator was around -18dB (in a 2400Hz IF bandwidth).

However it’s not a direct relationship between the transmission bandwidth, IF bandwidth and noise level. The resilience to errors, required level of operator experience and other similar factors will also play a part.

So would anyone like to suggest values ?