Damaged Whips; Detuning Circuit For Bottom Antenna Clip; Testing Cdma Antenna; Calibration Factors - Nokia RH-3 Series Troubleshooting - Antenna

CCS Technical Documentation

Damaged Whips

Figure 18: Whip stand-alone in retracted and extended positions
The above figure shows what the whip should look like when it is retracted and
extended. If the whip is damaged, simply use another.

Detuning Circuit for Bottom Antenna Clip

Figure 12 shows the bottom antenna clip. The detuning circuit is right next to the bot-
tom antenna clip. If the detuning circuit is not installed properly, then the internal
antenna gain will degrade by about 4-5dB at Cell band and 3-10dB at PCS band. The
detuning circuit consists of a 1nH coil inductor. If the inductor is missing, then install
one.

Testing CDMA Antenna

Calibration Factors

Defining AMS RF coupler CPL-8 calibration numbers will be conducted in the test
adapter MJF-28. The calibration numbers will be obtained by utilizing a phone with
known RF and antenna performance. Each test adapter should only require a single cali-
bration on PCS1900 and GPS bands at used test frequencies. Additional calibrations
should only be needed if the test adapter is substantially modified (reassembled, changed
parts, dropped, etc.).
Calibration Factor for PCS1900 frequency
Transmitter of the phone with known output power and antenna performance will be
turned on at the maximum output power (all bits up) by using call box. The transmitted
power will be measured on the RF connector and through coupler at CDMA PCS channel
1175. The difference between the transmitted and received powers will be used as the
calibration number (path loss on Cell band including coupler, cable, and attenuator path
losses) for the coupler on Cell band.
Nominal value for power measured at RF connector is 23 dBm. Coupler path loss is nor-
mally ~17...18 dB at PCS band. If 10 dB attenuator and cable with ~1 dB loss is used,
total path loss is 28...29 dB and measured power would be from -5 to -6 dBm [23 dBm -
(28...29 dB)]. However path loss has to be measured separately for every coupler since
path losses vary depending on used setup, cables, and attenuator.

Measurement Procedure for Cell800/PCS1900 phones

1 The phone will be placed display up in the test adapter MJF-28 with its whip
retracted.
Issue 1 06/2003
Nokia Corporation
Troubleshooting — Antenna
Confidential
RH-3
Page 15