M850-00
T858/859 Initial Adjustment
D3.3
Copyright TEL 31/09/98
3.1 Test Equipment Required
• DC power supply capable of delivering the following at 13.8V:
T858 >16A (e.g. Tait T807)
T859 >25A (e.g. Tait T808).
• Multimeter or DMM (e.g. Fluke 77).
• RF power meter (e.g. HP 435 series or Bird Wattmeter).
• 250W 30dB 50 ohm pad (e.g. Weinschel 40-20-34), or other suitable load.
• 300W 3dB 50 ohm pad (e.g. Weinschel 40-3-34).
• 'BNC' to 'N' type adaptors (e.g. Amphenol, Greenpar).
• Appropriate trimming tools.
Figure 3.1 T858/859 Test Equipment Set-up
3.2 Preliminary Checks
Check for short circuits between the positive rail and earth.
Set up the test equipment as in Figure 3.1.
Connect the T858/859 to a 13.8V DC supply.
Check that the quiescent current is approximately 45mA.
To key the transmitter, earth the key line (D-range 1 pin 13) on the exciter.
Check that the power supply is still at 13.8V under load.
Check that the regulated power control supply is approximately 7V (pin 1 of IC2).
Note:
The output power and alarm levels should be set with the cover shield on.
If the cover is removed for other adjustment procedures, make a final check
of the output power and alarm levels with the cover shield on.
Exciter PA Load
Tx Key
RF Power
Meter
Tx Enable
To Next Page
Loading...
Need help?
General
