Owner's manual

UHF Digital Hybrid Wireless
®
Rio Rancho, NM
7
The Smart Noise Reduction algorithm has three modes,
Selectablefromausersetupscreen.Theoptimalset-
tingforeachapplicationissubjectiveandselectedwhile
simplylistening.
OFF-nonoisereductionisperformedandcomplete
transparencyispreserved.Allsignalspresentedtothe
transmitter’sanalogfrontend,includinganyfaintmicro-
phonehiss,willbefaithfullyreproducedatthereceiver.
NORMAL-enoughnoisereductionisappliedtoremove
mostofthehissfromthemicrophonepreampand
someofthehissfromlavalieremicrophones.Thenoise
reductionbenetissignicantinthisposition,yetthe
degreeoftransparencymaintainedisexceptional.
FULL-enoughnoisereductionisappliedtoremove
most of the hiss from nearly any signal source of rea-
sonable quality and some high frequency environmental
noise,assuminglevelsaresetproperlyatthetransmit-
ter.
Supersonic Noise-Based
Dynamic Filter and Squelch
InadditiontoSmartNR,allhybridreceiversare
equippedwithasupersonicnoise-baseddynamiclter
and squelch system. The incoming audio is monitored
forenergyabove22kHz,pilottoneexcepted.Excessive
high frequency energy indicates that the received signal
istooweaktoachieveanacceptablesignal-to-noise
ratio.Undermarginalconditions,avariablelowpass
lterisrolledindynamically,maskingthenoisewhile
preservingasmuchofthetransmittedsignalaspos-
sible.Whenthechannelistoonoisyevenforthelter,
the audio is squelched.
Thisnoise-basedlterandsquelchsystemreplacesa
more or less equivalent system used for many years,
whichbaseditsoperationonRFsignalstrength.Perfor-
mance of the two systems is virtually identical, but the
noise-basedsystemrequiresnocalibrationandthere
isnobetterwaytotrackthesignal-to-noiseratiothanto
measure it directly.
RF-Controlled Digital Noise Filter
Inextremelyweaksignalconditions,anRFsensitive
variablefrequencylterisappliedtoreducethehigh
frequencyresponseofthereceiver.Thislterdoes
nothinguntiltheRFsignalstrengthdropsbelow3uVat
whichpointitbeginstorolloffhighfrequencies.Usable
audioremainsunaffected,butnoise-upsor“hits”occur-
ringnearthefringeofreceptionsoundmuchlessharsh.
Audio Output Level
Asetupscreenisprovidedforadjustingtheaudioout-
putlevelin1dBincrementsfrom-50to+5dBuusing
thefrontpanelUPandDOWNbuttons.
Test Tone
Toassistinmatchingtheaudiolevelsofequipment
connectedtotheSRa5PorSRa,a1kHzaudiotest
tone,adjustablefrom-50to+5dBuin1dBincrements,
is available at the XLR connector. This tone is available
throughtheTONEsetupwindow.
Power Supply
TheSRa5PandSRaisoperatedfromanexternalDC
powersource.Thepowersuppliesareprotectedfrom
damagetothereceiverthatcouldoccurifapositive
groundpowersourceisapplied.
LCD Display
Thedisplayhasfourprimarywindows.Pressingthe
FrontPanelSELbuttonstepsthrougheachofthese
windows.
Ifthebatterygetslowonthetransmitters,amessage
willinterruptthedisplayeveryfewsecondsandasha
low battery warning.
Afterpoweristurnedoffandbackonagain,theunit
defaults to the main window and to the most recent fre-
quency,audiolevel,transmitterbatterytypeandother
user settings. These settings are retained even when
thepoweristurnedoff.Afterveminutesofnokeyac-
tivity,theLCDbacklightgoesoffandthedisplayreverts
back to the main window.