
<!-- start -->
function cursor() {
document.dbs.Z.focus()
}
function getValues() {
if (isNaN(document.dbs.V.value)) {
alert ("Enter number for Voltage.")
document.dbs.V.focus()
document.dbs.V.select()
return false
}
if (isNaN(document.dbs.Z.value)) {
alert ("Enter number for Impedance.")
document.dbs.Z.focus()
document.dbs.Z.select()
return false
}
if (isNaN(document.dbs.dbm.value)) {
alert ("Enter number for dbm.")
document.dbs.dbm.focus()
document.dbs.dbm.select()
return false
}
if (isNaN(document.dbs.W.value)) {
alert ("Enter number for dbm / V.")
document.dbs.V.focus()
document.dbs.V.select()
return false
}
Z = parseFloat(document.dbs.Z.value)
W = parseFloat(document.dbs.W.value)
V = parseFloat(document.dbs.V.value)
dbm = parseFloat(document.dbs.dbm.value)
var W1 = 0
if (dbm <-89 && dbm >200) {dbm=0}
if (document.dbs.dbm.value == "" && document.dbs.Z.value !="" && document.dbs.V.value !="") {
dbm = 10 * (Math.log((Math.pow(V, 2) * 1000) / Z)) / Math.log(10)
document.dbs.dbm.value = Math.round(dbm * 1000000000000) / 1000000000000
return false
}
if (document.dbs.V.value == "" && document.dbs.Z.value !="" && document.dbs.dbm.value !="") {
V = Math.sqrt((Z * (Math.pow(10, (dbm / 10)))) / 1000)
document.dbs.V.value = Math.round(V * 1000000) / 1000000
return false
}
if (document.dbs.Z.value == "" && document.dbs.V.value !="" && document.dbs.dbm.value !="") {
Z = (1000 * Math.pow(V, 2)) / Math.pow(10, (dbm / 10))
document.dbs.Z.value = Math.round(Z * 1000) / 1000
return false
}
W = (Math.pow(10, (dbm / 10))/1000)
if (W >0.000000000001) {document.getElementById('wts').innerHTML="pico-Watts"; W1=W*1000000000000 }
if (W >0.000000001) {document.getElementById('wts').innerHTML="nano-Watts"; W1=W*1000000000 }
if (W >0.000001) {document.getElementById('wts').innerHTML="micro-Watts"; W1=W*1000000 }
if (W >0.001) {document.getElementById('wts').innerHTML="milli-Watts"; W1=W*1000 }
if (W >1) {document.getElementById('wts').innerHTML="Watts"; W1=W*1 }
if (W >1000) {document.getElementById('wts').innerHTML="kilo-Watts"; W1=W/1000 }
if (W >1000000) {document.getElementById('wts').innerHTML="mega-Watts"; W1=W/1000000 }
if (W >1000000000) {document.getElementById('wts').innerHTML="giga-Watts"; W1=W/1000000000 }
if (W >1000000000000) {document.getElementById('wts').innerHTML="tera-Watts"; W1=W/1000000000000 }
document.dbs.W.value = Math.round(W1 * 1000000) / 1000000
return false
}
function resetV(){
document.dbs.V.value = ""
document.dbs.V.focus()
document.dbs.V.select()
}
function resetW(){
document.dbs.W.value = ""
document.dbs.W.focus()
document.dbs.W.select()
}
function resetZ(){
document.dbs.Z.value = ""
document.dbs.Z.focus()
document.dbs.Z.select()
}
function resetdbm(){
document.dbs.dbm.value = ""
document.dbs.dbm.focus()
document.dbs.dbm.select()
}
function DefaultAll() {
document.dbs.V.value = ""
document.dbs.W.value = ""
document.dbs.dbm.value = "0"
document.dbs.Z.value = "50"
document.dbs.Z.focus()
document.dbs.V.select()
document.getElementById('wts').innerHTML="";
}
// js code from vk3khb.gak.net.au March2010
// end Voltage to dBm -->