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If you see a very small change and it does not go over the
1300mV it may be that the signal is not strong enough or there is
a problem with the detector or amplifier. First, try to increase the
signal level by repositioning the devices. The level you see will be
proportional to the input signal strength.
Unfortunately the level from the detector presented on U1 pin 3
may be so low the multimeter may not be able to measure it. You
may need more sensitive equipment. Because of this it is best to
check all the components in the detector and amplifier sections for
correct installation.
If you still can't get a reading then check the voltage levels on the
power supply connection of U1 and U2. [On both U1 and U2 pin
4 should measure about +9VDC and pin 11 should measure
0VDC, depending on the battery condition, when referenced to
the "-" lead of the battery]].
If you don't have the proper voltage or resistance readings you
can try tracing the connections between all components of the
defective section, using the resistance function of your multimeter,
all the way from input to the signal indicator, D6, in the case of the
315MHz section. Also verify that all components are installed
properly and the correct value for all sections..
IN CONCLUSION
Ideally your WCT3 functioned the first time and you didn't need to use this
section. Hopefully if you had a problem and have gotten this far everything is
working now. Otherwise it's easy for me to say that the WCT3 operation is
fairly straight forward and easy to troubleshoot but after all I designed it. In
reality it can be a tricky device to troubleshoot since we are working with very
low levels and it is very sensitive to noise at any of the signal frequencies we
are working with. This makes it hard to figure out the problem if you don't
have known signal levels to work with. Even in the lab it can be a challenge.
For these reasons don't be afraid to call us for help. We can usually help you
sort thru things. See "HOW TO RETURN YOUR WCT3 FOR SERVICE OR
CONTACT US FOR MORE HELP " on page 32.
WCT3 30
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