Techn

PIM is the production of unwonted signols, sometimes interfering with the bose receiver. Common couses of pttttinclude:Site

Guy wiresSleel towerOlher sites' IMDLighling

ccl Publicction 4rnE%A CommScope Compony

Possive Intermodulotion (PlM) Distortion Testing Guidelines

InstollotionPnnr[r tnrn, red ennnerigl5ScroichesContominof ion on conducting surfocesContominotion left in dielectric moteriql

MoteriolsHysteresisRusl

Ferromognelic moteriolsSemiconductive filmsPoor quolity ploting

Test EquipmentPoor quoliry loodsLow quolity or domogedirrmnerq ndonfers ondconneclors

SweepMensr rres ret.rrn Inss {Rl I nnel ir-]entifies ornss ellolsl|\Li' v|'v

Relol velv eosv to set rro ond meosJre

Distonce To Foult (DTF)Used to identify discontinuily or locote the foult for cobleRequires greoler understonding to interpret the results

PIMRequires proclices thot conkol the test equipment, conneclors, odoplers, jumpers, ond the surrounding RF environmenlRequires greoter knowledge to successfully interpret the resulisMore sensitive to RF poth foults, but olso very sensitive to other foctors besides the system being meosured

* RF System Condition moy yield eilher resull.

@ 2Cf.l,9 CommScope, Inc. All rights reserved. Andrew is q trodemo* of CommScope. All trodemo*s identified by @ or t' ore regisfered trodemo*s orlrodemorks, respeciively, of CommScope. This docurnent is for plonning purposes only ond is noi intended to modify or supplement ony specificotions or wor-roniies reloting to Andrew products or services.

RF System Condition Rt/DTF PIM

Open circuit Foil Poss

Short circuil r .lro tl Poss

Dent in cooxiol coble Foil Poss

Loose connection Poss or Foil* Foil

Woter ingress Poss or Foil* Poss or Foil*Corrosion Poss or Foil* Fo

Poor moterio l/components Poss or Foil* Foi

Contominqtion in RF poih filings, wire edge, ploting flecks Poss Fo

Poor fitting cooxiol coble to connector surfoce Poss Fqi

Dielectric moteriol between cooxiql coble ond connector moting surfoce Poss Fo

Split in flore due to over tightening Poss Foi

Crocked solder ioinl Poss Foi

Unmolched connector ports Poss Foi

lnternol ontenno foulb, loose screws, crocked ioints Poss Foi

Smoll crock in cooxiol coble Poss Foi

Loose brqid in iumper coble Poss Foi

TP-102945-EN (3/09) roge I of I

Verify Test Equipmenl Performonceo Volidote the test equipment. Use low lM jurnper, ooopters ono loodo Minimize number of odopterso Connector foces must be undomogedo Connectors must be tighto There should be no mechonicol stroin on the connectorso True verificofion of low lM requires swept frequency equipmentOnly use o lood with low lM. A regulor high power lood hos poor lM becouse of the obsorbing element. Use o low lM lood from lhe supplier of the lM test equipment^ 'l ' | | | llAVO|O Usrng o Ororded coble lumPero Most broided cobles hove ooor lM oerformonce becouse of o loose broid weoveo Some moy be good initiolly but con woTsen with repeoied flexing. Use o jumper wilh o continuous outer conductor iHEtlAyolDo not use old or worn odopiers. AII connections must be cleon ond tight ot both inner ond outer conductors. A loose conioct is on lM generotor. especiolly ot lhe iqner cond..rctorI Minimize the number of odopiersFor relioble lM meosurementso Components of the tesl equipment must be in good conditiono Use low lM iumper, odopters ond loodr Connector foces must be undomogedo Connector contocts must be unsfressedo Slpporl heovy itenso Use o iumoer to connect to ontennor ll.o n irrmnor ln nnnnarl ln lnrna.^hlo.. Verify test equipment performonceCoble preporotion must be done corefully ond correcdyr Use correct tools ond follow oll instructionso Cohle nrenorotion mrrct ho <^r^ra -o-h, 'rro! ond free of debris. Tighien clomping nut ond coupling nut to correct torqueField testing must verify thot onienno hos no interfering signolso A survey of the frequencies in use is recommended prior to the testing to eliminole locol frequencies from the test

$ot moy interfere with the PIM test. The inslrument ond test leods should be verified by o known good lood. The site should be verified with o "Golden Anlenno" to determine thot the instrument ond environment is copoble of moking

the meosurement. A<c,,ro thnt toct no..eppsl moinloin o Sofe distonce from the ontenno, os defined in FCC OET65, to ovoid hormful

eff--cts of R[ exnos,rreo Antennos not currenfly mounled or being tesied ot o worehouse need to hove o 'cleor sky"condition. lt is imporfont thot the on

lennq hos on unobslructed view of the sky ond is set owoy from neorby oblects to ovoid the possibility of PIM belng creotedby obiects which then show up incorrectly os ontenno PIM issues.

. Be sure to only lronsmit those frequencies which you ore licensed by the FCC to lronsmit

Actuol PIM meosuremenl should be performed using the some set-up os the site verificotion tesl lo minimize moving components,^l.l;^^ rnmnanonr< .hcnging the environment, etc. PIM meosurementerrors of +5 to + lO dB ore common when meosurrnglow-power signols which ore close to the noise or interference levels of the test equipment. Use of iesl equipmeni thoi signol powerlevels thot ore less thon 2O wotis connot be directly conpored to res,.rlts of test equipnent thot uses signol levels of 20 wotts.

O 2OO9 CommScope, Inc. All rights reserved. Andrew is o trodemo* of Commscope. All trodemorks identified by @ or rM ore regislered trqdemorks orkodemorks, respectively, of Commscope. This document is for plonning purposes only ond is not intended to modiFy or supplemeni ony specificoiions or wqr-ronties reloting to Andrew products or services.

TP-r 02e4s-EN (3/09) Poge 2 of 2