Originally Posted by kb79
alright, i've been playing with my rig and have a question that i'm sure is stupid and easily found elsewhere, but i'm apparently too dumb to find it:
Oh come on, you've got to be pulling our legs.....
The basic answers are in the links provided in earlier posts....
Trying to teach an entire class on radiowaves, modulation, etc. is well beyond the possibilities of an on-line discussion board.....and that is why you were given the links to the info that you need/desire.....
PLEASE read them.....
Now, the above was my first reaction to your recent post......and as I write this I'm having another thought......
Perhaps the above will be interpted as harsh???? and maybe that would leave you thinking this was a bad idea????
And, since that is not my intention.....here's my second thoughts...
ALL MF/HF Maritime voice comms are USB (Upper SideBand)......
If you had read the link USCG HF Voice
you would've seen the frequencies and mode (USB), are listed quite clearly.....(and if you follow further links to MF/HF Maritime frequencies, you'd find them easily....)
4426, 8764, 13089 kHz (USB)0430Z1030Z8764, 13089, 17314 kHz (USB)1630Z2230Z
And, for maritime WeFax and Text (SITOR), these links also show the mode to use (USB) and details on how to tune-in these signals....as well as further links to WeFax and Text decoding software
and/or receiving equipment
See tables below for abbreviated versions of radiofax broadcast schedules. Assigned frequencies shown, for carrier frequency subtract 1.9 kHz. Typically dedicated radiofax receivers use assigned frequencies, while receivers or transceivers, connected to external recorders or PC's, are operated in the upper sideband (USB) mode using carrier frequencies.
Assigned frequencies shown, for carrier frequencies subtract 1.7 kHz. Typically specialized marine communications equipment uses assigned SITOR frequencies while general purpose equipment uses carrier frequencies. Note that stations share common frequencies.
Since I've posted these links before, I'm sure there are some (myself included) that feel I'm wasting my time, but figured I'd spend just a few minutes and make one last effort.....
Typically all HF Ham radio
voice comms are USB on 14mhz and up....and LSB on 7.3mhz and below.....(to learn more about ham radio
, please use this link www.arrl.org
Originally Posted by kb79
hat's the difference between USB, LSB, FM, AM and CW modes? if i'm tuned to any specific frequency, i can select any one of these modes, but i don't get it - isn't a frequency a frequency?
The "mode" is the mode of modulation.....and it is the modulation that carriers the information.....
In this specific case, the information is a voice.....(or data that makes up a weather
chart or written words....)
If you think of your car radio for a moment, and forget about the IC-735, I think you'll get it....think of either AM of FM....
There are many radio stations transmitting on many different frequencies, and most all have different "information" carried on them (music, voices, etc.).....sometimes you run across (especially on "News Radio" and "Talk Radio" stations) the SAME information (like the same talk show, or the same news broadcast) on many stations at the same time......
USB = Upper SideBand
LSB = Lower SideBand
AM = Amplitude Modulation
FM = Frequency Modulation
CW = Continous Wave
Now, kb79, I realize that this is NOT a very involved technical explanation, but you've been given the resources to learn from and if you're unwilling to do this, that is your choice......
Good luck and fair winds....
s/v Annie Laurie
(GOD how much of an idiot do I feel like spending time giving information to someone that is "nameless"!!!!),