[aprssig] Delorme Earthmate

[Ron]

Sorda got side tracked with wife's aunt in hospital, but with the help of
Byon and the Yahoo Group, I learned that the DTR needs exactly +5VDC.  In
the past I got careless and tied the DTR and DSR together or a watch battery
3VDC or 3 AA 4.5VDC thru a 4.7K resister.  Apparently +5 is critical.  Now I
need a power source.  D7 puts out -6.8 TNC on.  As I remember, National
Semiconductor use to have a Negative input Chip which put out +5.  So far I
can't seem to find a part number and am not sure if it is still made???
Anyone got any ideas.  Would our old friend MAX 232 help???  I will keep
every one informed.  Thanks again to every one and there suggestions.
WA2WWK
Ron