2/2 - RFI fix continued
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The LM358 is a single supply opamp and can be substituted
with the LM2904, LM158, or LM258. (The dual supply 741 can
not be used as a substitute.) The opto isolator IC can be
substitued for many other types. The 4N35 has been tested
successfully. The discrete infared emitter/detector from
Radio Shack has been tested successfully.
I tried to use a darlington opto (TIL113), but couldn't get it to work. A
darlington opto circuit would only require 1.5ma average.
That would make battery life about 133 hours. Maybe I'll
try again later.
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MORE NOTES:
The 9v battery could be substitued with a 9 or 12 vdc
adapter. However I've found the clearest pictures occur
when both the radio and HAMCOM are running off batteries
... at 6am 8).
A 9v battery should last about 50 hours while audio is
present (assuming 200ma hours for a battery). If no audio
is present the battery will last 400 hours. The battery
life could be a problem for people who leave HAMCOM running
all night using the timed FAX option. Battery would only
last a week. If you have any advice or knowledge that could
improve this, please let me know.
copeland@metronet.com
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                            Ken
 * SLMR 2.1a * A friend in power is a friend lost.
--- Squish/386 v1.10
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