Specifications
SimradSH90
CWmeanscontinuouswave,whichmeansthatthetransmissionfrequencyisxed
duringtheentirepulse.WhenyouuseCWtransmissionyoucanchoosethelengthof
thepulses.Inasearchphaseundergoodconditions,youshouldtrysettingLong.Ifthe
conditionsworsen,trytoshortenthepulselength.Thiswillmakeiteasiertodistinguish
thevariousechoes,andthereverberationwillbereduced.
ThedefaultsettingontheSH90sonarisFMAuto.Inthistransmissionmode,thesonar
willautomaticallychoosetheoptimalpulselengthforthecurrentrange.
Aboutbeamwidths
Anarrowbeamwillalwaysreachfurtherthanawidebeam.Thisisbecausethe
transmittedpowerofthesonarisconcentrated.Nevertheless,youcaneasily“miss”a
schoolofshifyoumakethebeamtoonarrow.Iftherangeisreduced,itisthecommon
touseawiderbeam.
Figure5Beamwidths
ALarge
BNormal
CNarrow
ThenormalsettingontheSH90sonarisNormal.Thissettingisbasicallydesigned
forlongerranges.
YoumayalsotrysettingAuto.Thissettingwillautomaticallyadjustthebeamwidth
dependingonthecurrentrange.
AboutGain
Youcanadjustthegaininmanydifferentways,butthemostimportantisthesettingmade
bytheGainbuttonsontheOperatingPanelandontheHorizontalandVerticalmenus.
104
372739/D