LF: Testing on 500kHz

[qrss <qrss@talktalk.net>]

Currently running OP2 on 500kHz ver1.2.6 'readme' talks of OP2 and OP4 
for 500kHz but it is not implemented yet, here's to ver1.2.7:-)
Reports welcome just select 18MHz band in OPERA Soft. I will do the 
rest. it would be nice also to add a note in the Operator Tab that the 
RX frequency is 500kHz.
OP2 seems to do better than OP4 over the G3ZJO G0KTN path and OP1 a 
further improvement with this mornings variable signal levels (QSB).
73 Eddie G3ZJO