Selected Mode Memory Scan - Icom IC-RSOOCOL Instruction Manual

9-6 SELECTED MODE MEMORY SCAN
ch2 ch3 ch4
ch 999 ch7 ché
HSELECTED MODE MEMORY
SCAN OPERATION
@ Push [MODE] 1) Select mode.
FM MID BANK
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DE_SCAN] BANK 5
SEL MODE = FM
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[SCAN CONDITION] = with MAIN DIAL
While operating selected mode memory scan
Q: Why is it so difficult to increase scan speed?
A: The most important factor determining scanning
speeds is the PLL lockup time. The faster the
lockup time the faster the scanning speed.
However, when lockup times increase, the quality of
VCO output signals (C/N) decreases. Decreased
signal quality means the scan may not stop when a
signal is received. Lockup times and VCO signal
quality therefore work against each other.
How to solve the problem? Icom found a way. By
using the DDS (Direct Digital Synthesizer) in the
PLL circuit, the PLL creates a very short lockup
time.
Tech Talk from Icom
SCANNING 9
Selected mode memory scan repeatedly scans memory
channels with the same selected operating mode. Scanning
occurs in a bank or in all memory channels that can be
selected by the memory scan bank.
1) Set the memory scan bank. See p. 51 Section 9-5 (1)
SETTING THE MEMORY SCAN RANGE steps 1~ 4.
Memory scan edges do not function in selected mode
memory scan.
2) Select the desired resume condition. See p. 46 Section
9-1 (3) SCAN RESUME CONDITION.
3) Adjust the [SQUELCH] control to the threshold point.
4) Select the desired mode to be scanned, FM, AM, USB,
etc,
5) Push [MODE] in the [SCAN] switches to start selected
mode memory scan.
e At least 2 memory channels with the same mode must
be programmed to operate scanning.
6) Adjust the [SPEED] control to the desired scanning
speed,
7) To stop scanning, push a [SCAN] switch ((PRIO],
[PROG], etc.) or a CRT function switch ([F-1] ~[F-6] ).
The main dial also stops scanning.
Using the DDS, Icom succeeded in providing faster
scanning speeds without decreasing the quality of
VCO output signals. The scanning speed in the
IC-R9O0OL is 13 channels/second or more - a speed
at least twice as fast as former Icom equipment
(not equipped with the DDS system). And you can
be certain that the IC-R9000L's scan will stop when a
signal is received.
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