CommRadio CR-1a User Manual – Rev 1 Edition: 15 July 2015
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8: External Speaker:
Internal amplifier delivers 0.8 Watts into 8 Ohm Speaker.
3.5 mm (1/8”) female-mono-socket (tip and ring).
•
Both speaker wires connected to the tip and ring of the external speaker socket
MUST
be un-grounded to avoid internal amplifier damage.
•
Not intended for sound-card or amplified speakers. See
Headset Jack
on page 3.
9: MW-HF Antenna Port 1:
BNC Female – 50 Ohm.
10: VHF-UHF Antenna Port 2:
BNC Female – 50 Ohm.
11: External Chassis Ground Connection:
4/40 Phillips pan-head screw with 1 lock-
washer and 2 flat-washers to hold wires and lugs.
The CR-1a is designed with ESD diodes on all antenna and power input jacks, knobs and
keys.
It is good practice to ground the CR-1a to discharge static electricity from antennas and if
other equipment is nearby that may cause reception interference.
In settings such as a room with indoor antennas, or outdoors with temporary antennas it
is not necessary to ground the CR-1a.
WARNING: During active lightning storms, it is wise to disconnect antennas from all radio
equipment.
12: Internal Lithium-Ion Rechargeable Battery (not shown).
The internal battery is a Tenergy model 30006, Li-18650 3.7V 2600 mAh with internal
protection circuitry. 18650 type cells from other manufacturers may not fit the internal
battery holder since they vary in diameter and length.
Less than 1 gm of lithium is used in this cell and therefore it is well under the limits for
cartage on aircraft.
It is important to replace with same/similar batteries that
have internal protection circuitry. CommRadio stocks
these batteries and can provide them for a nominal
charge.
