Frequency Counter Off-Air; Frequency Counter Direct Connection - Ramsey Electronics COM3010 User Manual

3.10.03 Frequency Counter Off-Air

This test allows the user to count the frequency of a transmitter off-air. This is especially useful
for identifying the frequency of unmarked radios.
1. Connect the whip antenna to the COM3010's RECEIVE IN jack.
2. Turn off all FM modulation modes by pressing
3. Press COUNTER
band and gate time desired. See "2.09 Using the Frequency Counters" for more infor-
mation.)
4. Key the transmitter; the count will appear in the lower left field of the RECEIVE screen.
5. While still keying the radio the user can press
frequency.
6. Pressing
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Note: The counted frequency can be rounded to the nearest step size of each display. This
makes it easy to check for frequency alignment since you can set the step size to the channel
size.
Do not reproduce or distribute.
Setting the step size to the channel size causes the COM3010 to set the Receiver or Generator
to the channel frequency, not the counted frequency, which is important if the radio being
tested is off frequency. The rounding function can be toggled on and off in the Options Menu.
To accomplish this press:

3.10.04 Frequency Counter Direct Connection

The COM3010 can be used as an RF frequency counter by connecting a Coaxial cable, 50
ohm probe, or "sniffer" loop to the RF input. The RF counter has many useful purposes includ-
ing the frequency alignment of Transmitters, Receivers, and crystal oscillators.
1. Connect a 50 ohm probe, cable, or sniffer loop to the RECEIVE IN jack.
Warning - Do not under any circumstances connect a transmitter to the RECEIVE IN jack
of the COM3010 or damage will result!
2. Turn off all FM modulation by pressing
3. Bring the loop close to the oscillator, or connect the probe to the appropriate test point.
4. Press multiple times to select RFL, RF
band and gate time desired. See "2.09 Using the Frequency Counters" for more infor-
mation.)
multiple times to select RFL, RF
on the generator side will set the generator to the counted frequency.
TYPICAL TEST PROCEDURES
(Mod Off).
, RFH or RF
L H
to set the receiver to the counted
(Mod Off).
, RFH or RF , depending on frequency
H
L
39
, depending on frequency