--- In [email protected], "kg4wmp" <[EMAIL PROTECTED]> wrote:
>
> I could find nothing
> specific on why a radio whould need 4 (or more) 5C's and 1 EC. Do
> they take an average over several crystals or something or was this
> a function of multiple channels?
Normally a mobile set only needs one 5C or 2C ICOM. The EC units are
slaved to the correction that the 5C creates for itself. The radio
could have the buss cut and use separate Master and slaves for TX and
RX. It is not normally recommended to use multiple 5C units. This
will cause the units to fight each other. Theeir temp. comp. will
not be correct. But on low band and for ham use, put in what you got
and use it. Some of the MII repeaters in this area don't bother with
any temp. comp. at all.
The master ICOM has a selected thermistor and resistor combination
which produces a correction voltage to a tuning diode (varicap). If
I remember right the 2C units have to have the parts selected, but
the 5C units don't. The EC units have the tuning diode and get the
correction voltage from the master. If two masters are tied together
the voltages fight.
Some guys use EC ICOMs and modulate the varicap. Its good FM but
generally low deviation. Most repeaters source their +10V from a
separate source for TX and RX. This separation prevents any RX side
noise from adding spurious to the TX. Simplex transmitters don't have
the problem as the RX is off during TX. Repeaters do have the
problem without this extra separation.
More GE trivia! WE can take this off line if you'd like more poop. R-
B website that Kevin has is a great source book. Once you get a
manual your off. Many mobile use the same key. I'm not sure if the
station key or the mobile key is stamped BF-10 anymore. Nearly any
2way shop has a ley to unlock it. I'd just use the master key
(electirc drill). Then vaccuum the mess out of the radio.
73 Ed K3SWJ
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