[aprssig] Delorme Earthmate
rgilson at adelphia.net
Sat Jun 25 21:02:36 CDT 2005
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.
More information about the aprssig