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Part 3 : Receiver RF Levels and Checks
This section shows the typical RF levels expected throughout the receiver path
and the expected control voltages for both the UHF and IF synthesisers. A block
diagram showing the locations of the RF measurement points and levels is shown
in figure: 3.1.
Part 3.1 : Receiver Testing Set-up
To check the receiver the following conditions have to be set:-
1. On a signal generator or a GSM/PCN test box, output a CW signal of amplitude
= - 40dbm's at either:-
947.467708 Mhz (CH62)
or
1842.467708 Mhz (CH699)
2. Set the d.c. power supply to 3.8volts.
3. Using the GSM/PCN test jig power up the hhp and via the keypad enter the
following menu options to put the hhp into receive mode:-
• Press
"C"- (RX Options). Once this key is pressed the hhp should display:-
"Suspend Mode
Function Id"
This message indicates that the HHP has entered engineering test mode.
• Press "A or B"
according to which rx frequency band is required.
A = GSM900
(ARFCN:62),
The hhp is now set to receive mode = Continuous on channel 62 or 699
respectively.
•
The receiver parameters can be altered by another sub menu, these being:-
A. Change Channel
B. Set Receiver Mode
C. RX Lev Report
Note:
The additional 67.708 Khz on top of the carrier frequency is used to simulate a
logic 1 Equivalent on the I and Q outputs of the PMB2410.
All RF values shown are only intended as a guide figure and may differ from
readings taken with other test equipment and leads. Lead and connector
losses should always be taken into account when performing such rf
measurements.
when testing the GSM rx path
when testing the PCN rx path
B = GSM1800
(ARFCN:699)
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