I recently modified a spare “F” HRO-5 coilset (500-960 kc) to bandspread the 630M band, providing 10 divisions per kilohertz now.
There is some frequency drifting on the order of +/- 20 Hz, but I wanted to see how well the receiver would hold up decoding WSPR stations on the band. Below is a capture of the WSJT-X 1.6.0-devel waterfall showing WSPR signals:
Despite the less-than-perfect stability, there have been numerous decodes as seen in the WSPRnet.org database listing:
