Gorman Redlich Manufacturing Co CRW-S 사용자 설명서

 
 
Suitable outdoor antennas are available from Gorman-Redlich.  Either a vertical quarter-wave 
element with three horizontal radials, or 6-element Yagi can be supplied, cut to the correct 
wavelength. 
 
Daily variations in signal strength may be noticed, particularly at extreme range. Signals are almost 
always strongest just after sunrise, diminishing to an early-afternoon minimum.  Weather 
conditions such as ground fog can produce short-lived signal enhancement. 
 
 

 
Some simple tests may localize trouble. Note whether the green power-on LED is illuminated with 
normal intensity.  If not, a failure in the unregulated power supply transformer may have occurred 
or the 5 volt regulator U4. 
 
Note whether the “RELAY CLOSED” indicator LED functions with normal intensity.  This LED is 
energized with regulated voltage, and if it fails to operate, failure of the voltage regulator (U4) may 
have occurred or failure of IC U20.  If the relay audibly operates, but the indicator LED does not 
function, the fault is most probably in the LED. 
 
If receiver noise is heard but no stations can be received, the failure may have occurred in one of 
the local oscillator, in the antenna, or in the antenna feed line.  To check the first local oscillator 
power down the receiver.  Push the #6 dipswitch down and power the unit up.  All the LED’s will 
be on and the alert LED will flash, put a test lead between TP1 and GND and use a counter to 
measure the frequency of the 1

st

 local oscillator crystal.  The 8 MHz crystal should be operating 

within 

±  2 PPM of 8 MHz ( ±  16 cycles) trimmer cap C44 may have to be adjusted with a 

jeweler’s screwdriver to bring the 1

st

 local oscillator to 8 MHz. 

 
Normal reception but failure to demute when the 1050 Hz alert tone is transmitted may be due to a 
failure of IC4, IC5 or IC 6.  If the “MUTE-DEMUTE” switch works normally, IC5 and IC6 are 
okay. 
 
 

The CRW-S receiver uses stable components and crystals with a slow aging rate, so it should 
seldom, if ever, need realignment.