DANIELS
ELECTRONICS LTD.
TM
VHF Enhanced Extra Wideband Receiver Instruction Manual IM10-VR3H040-AB
5-3
5.1.4
Power Supplies
A check of all DC power supply levels is recommended before receiver alignment is performed.
All supply and reference voltages are fixed with no provision made for adjustment. The
following test points and their respective levels apply: Note that total receiver current should be
less than approximately 100 mA for a synthesized unit and 45 mA for a crystal controlled unit.
Higher currents indicate that immediate corrective action/repair is required.
TP1 +6.0 Vdc ± 0.1 Vdc. U1 positive regulator output.
TP2 -6.0 Vdc ± 0.1 Vdc. U12 negative regulator output.
TP3 +4.75 Vdc ± 0.1 Vdc. Virtual ground reference source.
TP13 +2.50 Vdc ± 0.02 Vdc. U15 squelch threshold reference.
Note that incorrect bias adjustment (R13) of IF amplifier MOSFET Q1 can add significantly to
the overall receiver current figure.
Total typical receiver current consumption of an enhanced synthesized receiver may be broken
down as follows:
• IF / Audio Main Board approximately 22 mA;
• FE-3H Enhanced Front End approximately 160 mA;
• OS-3H Enhanced Synthesizer approximately 160 mA (Operate Mode);
• IF Enhanced Buffer Board approximately 30 mA