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Related Manuals for Philips TW0200
Summary of Contents for Philips TW0200
- Page 1 Chapter 7...
- Page 8 7-1.5 Meters for M/W System 1. Power Meter Anritsu - ML 4803 A 2. Power Meter HP - 437 B, 4368, Philips 3350 3. Spectrum Analyzer- Anritsu MS 7101 B,10 KHz- 23 GHz, 22 GHz- 140 GHz. 4. M/W System Analyzer (MSA) Transmitter & Receiver ME 538 M Anritsu 4510 B Transmitter and Receiver.
- Page 9 7-1.6 Before proceeding any M/W system A/T --------- 1] Get TT-O, TT-1 duly filled in all respect, 2] Collect Survey report which includes, - Check list - Route details - Site survey report - Particulars at a glance - Clearance calculation - Path data calculation - Rain attenuation calculation - Availability calculation...
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Page 22: Microwave System
7-2 MICROWAVE SYSTEM Microwave A/T comprises of - Local A/T of all stations, and Repeaters. - Hop Test. - Through Test. 7-2.1 Local A/T:- There are several makes of Narrow / Wide band microwave systems, near about all test are same except power supply points, access points. Here for example Satara M/W station to T.E. - Page 24 3. Test on receiver:- Check of RLO frequency :- Check of RLO frequency with unritsu or HP frequency counter, measure frequency and offset Write assigned measured and deviation in PPM limit ±20 PPM Measure RLO output level at RLO mon limit ≥-12 dBm Feed Receive RF frequency at a level of -30 dBm at RX, RF and record 1.RF frequency limit ±250Khz 2.
- Page 25 7-2.2 VSWR: - Voltage standing wave ratio Standing wave :- If the impedance of the load (Antenna) and source ( Generator ) is not equal, that is not matching then part of the energy is reflected back towards the source., some power is absorbed and rest is reflected .this interference form one set of waves V &...
- Page 27 MSA Transmitter IF O/P -10 IF in 75 Ω termination MSA Receiver Counter IIF return loss IF in on Rx card Fig. 7-10 Conversion chart of VSWR, Return Loss and SWR. VSWR Return loss Reflection In dB Coefficient In dB 1.01 46.1 0.086...
- Page 30 Please see the Wiltron diagram, Anritsu detector converts power into voltages. Connect Open , select Connect Short , select Connect device , Start select, Function, Max /select -20 dBm, Min / select -34 dBm, Cursor also move for max to minimum. Wiltron Generator: - See Fig.
- Page 31 . Check of BER with IF Loop: - oop IF Trans to If Receive and test 140 Mb/ STM-1 on DTA set for 0 PPM and ± 15 PPM. The result should be 0.00 E 5. a) Trans Branching Filter loss: - The difference between Trans Power at PA out and antenna port will be a Trans Branching Filter loss.
- Page 32 7-2.4 HOP A/T OF 11 GHz 140 Mbps or STM-1 1] Receive level: - Note down Surveyed level, Nominal level and measure Rx RF level at Rx IN by power meter with suitable sensor and pad by removing the W/G from RF IN. - The same Rx RF level can be easured with calibrated spectrum analyzer and by tuning the required frequency of a channel, deviation between measured and survey...
- Page 33 4] BER measurement:- - Ask distant station loop on 140 Mb or STM-1 which is installed. - Carry out BER Test as usual for 0 and ± 15/20 PPM. - Take out printout for each channel/PPM , - Limit: - 1x 10 E J tter measurement :- ( as mentioned in OFC systems Pl) Carr y out I/P Jitter test for both Main and Protecti...
- Page 34 7-3 Microwave constituents 1. Antenna: - It is a metallic device which transmits and receives Radio signals 7-3.1 in the form of electrom agnetic waves. Antenna used for the transmission of Radio, TV, , GSM and CDMA network. There are two types of antennas. 1. Omni directional (radiates equall y in all direction) It is a simple rod.
- Page 35 7-3.2 3. Link Budget:- Link budget is to calcula te particular M/W system Receive level taking into consideration all gains and losses in the ne rk. It accounts attenuation of transmitted signal due to propagation. Formula: - Pt + Gt + Gr – L – FL –...
- Page 36 7-3.3 5. Fresnel zone: - No. of concentric ellipsoid revolutions which defines volumes in radiation pattern of ircular aperture and it is due to diffraction by circular aperture The first zone is circular; sub second zones are annul ar in cross section and concentric with first.
- Page 37 Rain attenuation: - As the water droplets scatters and absorbs radiation the effect of -3.4 8. rain go es on increasing with the increase of frequencies i.e. it is more in 13 GHz system compared to 4 and 6 Formula A (dB) = 0.0308 f – 0.1872R, R - Rain rate at that location = ------------ Where f = operating frequency within 10-15 GHz This rain attenuation can be reduced by interconnecting two stations separated by di stance...
- Page 38 Antenna diversity: - In this diversity schem microwave signals are transmitted along with different propagation path with the help of second antenna at receiving end to improve received performance. 7-3.5 10. Hot stand by: - If main equipment fails automatic switch over takes place on a stand by equipment set i.e. a complete set of parallel equipment is switched in almo st instantaneously on failure of operating equipment.
- Page 39 13. Wayside dropping: - If any small station in any hop requires 2 MB stream, an additional card is provided in system so as to handle the traffic of small station along with main M/W system. 14. IF DADE: - Di fferential Absolute Delay Equalizer.
- Page 40 2 GHz / 8 MB D/ UHF System A/T Make: - ARM-2208-M3 7-4.1 Specification: - Frequency band 2.0 to 2.3 GHz. Bit Rate 8.448 MHz 75 Ω. Tx- Rx Spacing 161 MHz. RF Tx: +30 to +32 dBm at antenna port. Receive IF frequency 70 MHz.
- Page 42 - Disconnect RF cable from Rx In. - Make a test set up as above for AGC calibration. Select RF frequency and level say -40 dBm and calibrate it for the correct O/P level. Put ON RF O/P and monitor AGC voltage. Note down AGC voltage up to -75 dBm in steps of -10 dBm and there after in 5 dBm steps when E LED lights.
- Page 43 7-4.4 HOP/ through A/T 1. Receive level: - Measure RF Rx level at Rx IN and compare it with surveyed level. Deviat ion between surveyed and measured level should be within ±1 dBm. (Ref: - DOT ML sector 7 GHz/ 34 Mb) 2.
- Page 44 Tele command status TC1, TC2 OFF. 6. BITE Alarms: - Eqpt fail: - Any Eqpt failure. System fail: - Any System failure. Microprocessor fail: - When processor in supervisory card out. OB call tone busy: - When Bus call is sent EOW: - When O/W call is in progress.