Wednesday 7 July 2010

70 MHz WSPR

There's some activity on 70 MHz WSPR now, on 70.0286 MHz. I can receive G0MJI from Liverpool, using my Icom IC-7000 and the dual band 2m/70cm colinear on my chimney. On the proper 70 MHz dipole in the loft, there is no improvement in S/N because there is more noise indoors. I've nothing to transmit on 70 MHz SSB though.
Alex G7RNX in Dalton was also on 70 MHz WSPR on Sunday and could be received by G0MJI and G3ZOD (Stockport).

Made a PC to radio interface for an FT-847 before finding out it wouldn't work properly because...
On the Yaesu FT-847 there are separate connectors on the back for FM and SSB data modes. The 6-pin mini DIN socket can only be used to transmit on FM (there seems to be receive audio on SSB through it though). On SSB, transmit and receive audio are through a 3-pole minijack socket. The tip of this jack is for transmit audio and PTT (ground through a resistor to transmit).
The 6-pin socket can be used for the PTT on both FM and SSB.
Connecting a cable directly between the headphone socket on a PC and the FT-847's SSB data socket made the radio stay on transmit. There needs to be a capacitor to block any DC current path which might key it up.
It seems a bit of a strange thing to have 2 data sockets but when the FT-847 was designed, people weren't using a PC sound card for data modes so would have had a standalone packet TNC.

1 comment:

Roger G3XBM said...

Just getting a transverter together for 4m QRP and certainly intend to give WSPR a go on the band as I am a great fan of the mode.