3.2
Introduction To Servicing
M2000-00
31/10/96 Copyright TEL
3.1 Servicing Precautions
3.1.1 Caution: Accidental Transmit
Under certain circumstances the microprocessor can key the transmitter. Ensure that all
instruments are protected from accidental transmit at all times.
3.1.2 Caution: Antenna Loading
The equipment has been designed to operate with a 50Ω termination impedance, but
will tolerate a wide range of antenna loading conditions. However, it is strongly recom-
mended that the transmitter is not operated in the absence of a suitable load. Failure to
observe this precaution may result in damage to the transmitter power output stage.
3.1.3 Caution: Beryllium Oxide & Power Transistors
The RF power transistors in the T2000 all contain some beryllium oxide. This substance,
while perfectly harmless in its normal solid form, can become a severe health hazard
when it has been reduced to dust.
For this reason the RF power transistors should not be scratched, mutilated, filed,
machined, or physically damaged in any way that can produce dust particles.
3.1.4 Caution: CMOS Devices
This equipment contains CMOS Devices which are susceptible to damage from static
charges. Care when handling these devices is essential. For correct handling procedures
refer to manufacturers’ data books covering CMOS devices, e.g. Philips Data Handbook
Covering CMOS Devices; Motorola CMOS Data Book Section 5 (Handling Procedures),
etc.
The following diagram shows a typical anti-static bench set-up.
Figure 3.1 Anti-Static Bench Set-Up
to building earth
(not mains earth)
via 1M series resistor
metal frame
conductive
wrist strap
conductive rubber
bench mat
To Next Page
Loading...
