Andrew PCSSSR1900 PCS repeater model PCSSSR1900 User Manual PCS SSR INSTALLATION

Andrew Corporation PCS repeater model PCSSSR1900 PCS SSR INSTALLATION

Users manual

INSTALLATION & OPERATION MANUAL FOR THE BETAMODELS OF THE PCS SSRContents:1.0 Description1.1 Physical Configuration1.2 Electronic Description & Block Diagram1.3 Operational Environment2.0 Installation Guide lines2.1 Location2.2 Mounting2.3 Power Supply3.0 Operation Guide Lines3.1 Power / Interface Circuit Board3.2 StabilityAppendix A: PCS Frequency Band and BlocksAppendix B: SpecificationsAppendix C: Gain Adjustment1.0 DescriptionWARNING: This device complies with CFR 47, Part 24 of the FCC rules.Any modification not expressed approved by the manufacturer couldinvalidate the user's authority to operate the device.1.1 Physical ConfigurationFigure 1 is an illustration of the 18” PCS Side to Side Repeater (SSR) indicatingimportant features; Figure 2 is an illustration of the 12” SSR. As shown in theillustrations both SSRs have a square shape with rounded corners; both units have thesame physical thickness (approximately 2”). The 18” unit weighs approximately 14.5pounds; the 12” unit approximately 8 pounds. The 2” wide edge of both units contain4 deep grooves separated by fins; this structure is an important electrical feature andmust be keep free of extraneous material. Likewise, the central 8” square area oneach face is electrically active and must be kept free of contaminating materials.Take special note that each face of the SSR has a unique electrical function and mustproperly oriented in operation (see section 2.0). The illustrations show the SSRwithout the radomes normally attached to each face. When attached the radome withthe Andrew flash indicates which side should be facing the handset (mobile unit).1.2 Electronic Description & Block DiagramThe 1900 series PCS repeaters operate in the 1900 MHz PCS band. They weredeveloped to provide more reliable coverage and/or range extension of PCS systemswithin sheltered structures. Specific models for each of the major US PCS sub-bands
( A, B, C, D, E & F) are offered. Pre-aligned antennas on each side of the repeatersmake them easy to install and simple to operate. Designed for indoor environments,they only require a standard US 110VAC outlet for operating power. All threepopular PCS systems (TDMA, CDMA & GSM) are supported.Figure 3 is an electronic block diagram of SSR internal and external circuitry.Separate antennas provide receive and transmit functions for the complementaryuplink and downlink bands. In operation, the appropriate receive antenna feeds its’signal to a band pass filter that functions to reject undesired signals and isolate thecomplementary band’s signal. The signal from the band pass filter feeds an amplifierwith an AGC loop that limits maximum output power to approximately 100milliwatts. The amplifier output feeds a second band pass filter functioning to limitspurious amplifier output signals and further isolate the complementary band’s signal.The complementary band’s signal path is identical to that previously described,except in the reverse direction. Both amplifiers include crude RSSI circuitry andover-current protection circuitry.1.3 Operational EnvironmentThe SSR has been designed to operate properly in a temperature and humiditycontrolled indoor environment. Operation in environments where the ambienttemperature is outside the 50o-85o F range or the relative humidity is greater than 50%may result in unsatisfactory performance. Exposure to temperatures outside the 10o-120o F range or relative humidity greater than 80% may result in permanent damageto the unit.2.0 Installation Guide Lines2.1 LocationCAUTION: In order to comply with FCC rules for rf exposure, the following mustbe observed:The antenna must be installed such that a minimum separation distance of 20 cm. ismaintained between the antenna and any persons.Proper operation of the SSR cannot be achieved if the following installation locationguide lines are not followed.The prevention of signal feedback from the transmit antenna on one side of the SSRto the same path’s receive antenna on the opposite side of the SSR is paramount toproper operation of the SSR. Any matter in the surrounding environment of the SSRwill produce undesirable feedback signals. Any object with any physical dimensionthat is greater than 2 inches may cause undesirable signal reflections and/orrefractions severe enough to cause unstable operation of the SSR. Metal objectsnormally cause worse reflections and/or refraction than non-metallic objects. Thelevel of undesired reflected and/or refracted signals is directly proportional to the sizeof the object and inversely proportional to the distance between the SSR and the
reflecting/refracting object. Obviously, a perfect “free space” environment for theSSR is the ideal location, but not practical. However, a major goal of the operatinglocation selection process is to find a place that approximates a “free space”environment as closely as possible.A location that provides a “clear” communication link with a suitable base stationsignal using a typical handset is also required for proper operation of the SSR. Basestation signal level at various candidate locations should be measured using the RSSIon a handset or more precise instrumentation. Experience indicates that a locationwith the highest base station signal level that is free of any object within a 15-20 feetradius hemisphere centered on one side of the SSR should provide suitable SSRoperation.2.2 Mounting ConsiderationsMounting should be accomplished with due consideration of the minimization ofundesirable feedback signal discussed in section 2.1. Early product developmenttesting used 50 lb. braided nylon cord and small “S” hooks to hang the SSR four ormore feet below a convenient overhead structural member (see Figure 4). Mountingdevices made of non-conductive, low dielectric constant and/or high loss tangentmaterials attached to any edge that minimally blocks the grooves between the fins onthe edges may be used to mount the SSR.2.3 Power Supply Location & ConnectionsThe power supply furnished with the SSR requires a standard US 110 VAC outlet. Itconnects to the SSR via a permanently attached two-conductor cable with a specialpolarized connector and RF absorbing material on approximately 18” of lengthadjacent to the SSR. The location of the power supply also requires special attentionto the minimization of undesirable feedback signals. The recommended location is asnear the plane that bisects the SSR around the finned edge as possible and as far awayfrom the SSR as possible.3.0 Operation Guide Lines3.1 Power / Interface Circuit BoardAll controls and indicators for the SSR are mounted on the power / interface circuitboard (PWR I/F); which is mounted in one of grooves between the edge fins (seeFigures 1 & 2). The four small LEDs mounted on the PWR I/F provide the followinginformation:On state indicates that SSR is receiving powerfrom the power supply and the internal circuitryhas not exceeded the maximum safe currentdemand.Green LED at edge of PWR I/F most distantfrom power connector.Off state (concurrent with an off state for theadjacent Red LED) indicates that the SSR is notreceiving power from the power supply.
On state indicates an internal over current eventhas occurred. Power to the SSR must beinterrupted for 10 or more seconds to reset this“circuit breaker” function. Repeated resets(more than 3 times in 30 minutes) may causepermanent damage to SSR.Red LED adjacent to Green Power LEDdescribed above.Off state (with concurrent on state of powerLED) indicates normal SSR operationGreen LED nearest power connector. RSSI for the down link (signal received fromthe base station and re-transmitted to thehandset). On state indicates reception of auseable signal from the base station.Green LED next in line away from powerconnector. RSSI for the up link (signal received from thehandset and re-transmitted to the base station).On state indicates reception of a useable signalfrom the handset.3.2 StabilityAfter mounting the SSR in a location selected using the guidelines of section 2.0 andconnecting the power supply stable operation must be confirmed. If stable operationin the selected location cannot be achieved, either another stable location must befound or the gain of the SSR must be reduced (see Appendix C).A good way to confirm stable operation is by use of a spectrum analyzer and asuitable pick-up antenna. Locate the spectrum analyzer and pick-up antenna outsidethe 15-20 feet clear field hemisphere of the SSR, adjust the analyzer controls todisplay signals in a 150 MHz band centered on the operating band of the SSR (seeappendix A), and set the analyzer bandwidth, attenuation, and sweep parameters toprovide –90 to –100 dBm measurement sensitivity. Turn off the SSR by removingits’ power cable; while viewing the analyzer display, turn the SSR back on and watchfor spurious signals that change amplitude and frequency in a random manner. Thepresence of such randomly changing signals is a strong indication of an unstable SSR.With a normally operating SSR you should be able to see the base station down linksignal and this signal should increase in amplitude when the SSR is turned on (SeeFigure 5).If a spectrum analyzer is not available, a less certain but useful way to confirmsatisfactory operation is to make a phone call using a hand set that operates in thesame band as the SSR. The audio quality is usually badly garbled and distorted whenthe SSR is operating in an unstable manner.
Figure 1. 18” Side to Side Repeater
Figure 2. 12” Side to Side Repeater
Figure 3. Side to Side Repeater Block Diagram
Figure 4. Typical SSR Installation Mounting
Figure 5. Example of Spectrum Analyzer Display of Base Station Signals forStable Operation of the SSR
APPENDIX A. PCS Frequency Band and BlocksBand/Block Channel Numbers Mobil Station TransmitFrequency (MHz) Base Station TransmitFrequency (MHz)A 0-299 1850-1865 1930-1945D 300-399 1865-1870 1945-1950B 400-699 1870-1885 1950-1965E 700-799 1885-1890 1965-1970F 800-899 1890-1895 1970-1975C 900-1199 1895-1910 1975-1990
APPENDIX B: SpecificationsCommon to all Models:Model 1900-xxx -12A & -18A -12B & -18B -12C & -18C -12D & -18D -12E & -18E -12F & -18FRx Freq (MHz) 1850-1865 1870-1885 1895-1910 1865-1870 1885-1890 1890-1895Rx NF 5.5 dB MaxTx Freq (MHz) 1930-1945 1950-1965 1975-1990 1945-1950 1965-1970 1970-1975Tx Pwr +20 dBm typical; +21 dBm MaxACPR -50 dB Min @ ±885 kHzPower @110VAC 20 watts MaxTemp Range 50 to 85 oFCommon to all 12” Square Models:Rx/Tx Active Gain 45 dB minSize 12” X 12” X 2” less Power SupplyWeight 8-1/2 lbs less Power SupplyCommon to all 18” Square Models:Rx/Tx Active Gain 50 dB minSize 18” X 18” X 2” less Power SupplyWeight 14-1/2 lbs less Power Supply
APPENDIX C: Gain AdjustmentThe small multi-turn potentiometers (pot) visible on the edge of PWR I/F board between thepower connector and the row of LEDs may be adjusted to reduce the electronic gain of theSSR (see illustration below). Keep in mind that proper location of the SSR is the best waystabilize the SSR. Gain reduction will drastically reduce the range over which the SSR canprovide signal improvement. Rotation of the adjustment screw clockwise will reduce thegain of the SSR. Adjustment sensitivity is approximately 1 dB per turn in the mid range ofthe pot. The pots have a slip-clutch action at each end of their range to preclude accidentaldamage during adjustment to the desired setting.

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