Surface to diver radio?

Grumman-581 wrote:
> On Tue, 08 Aug 2006 05:52:03 -0400, nitespark <nitespark@cox.net>
> wrote:
>
>>Actually, the units from OTS are SSB
>
>
> SSB implies AM type modulation... That's not to say that someone
> couldn't design something using FM type modulation, but for the most
> part, FM type modulation tend to be at higher frequencies and as such,
> they do not propagate through water as well as lower frequencies, thus
> the range would not be as good... VLF and ELF get very good
> propagation through water, but no one really wants to have to carry
> that long of an antenna around with them... <grin>

The reason FM would not be very well suited for that application is due
to bandwidth. Typical commercial band, bandwidth is +/- 5khz with some
intersitial frequency stuff at +/- 2.5khz. Even that is fairly wide at
the VLF or ELF (not sure where VLF and ELF break) stuff the OTS
equipment operates on which is around 39khz.

The local dive team has some and they love them. I have never used
wireless but have used tethered. The times I have been around the
wireless, I was impressed at the performance.

Grumman-581 wrote:
> On Tue, 08 Aug 2006 05:52:03 -0400, nitespark <nitespark@cox.net>
> wrote:
>
>>Actually, the units from OTS are SSB
>
>
> SSB implies AM type modulation... That's not to say that someone
> couldn't design something using FM type modulation, but for the most
> part, FM type modulation tend to be at higher frequencies and as such,
> they do not propagate through water as well as lower frequencies, thus
> the range would not be as good... VLF and ELF get very good
> propagation through water, but no one really wants to have to carry
> that long of an antenna around with them... <grin>

The reason FM would not be very well suited for that application is due
to bandwidth. Typical commercial band, bandwidth is +/- 5khz with some
intersitial frequency stuff at +/- 2.5khz. Even that is fairly wide at
the VLF or ELF (not sure where VLF and ELF break) stuff the OTS
equipment operates on which is around 39khz.

The local dive team has some and they love them. I have never used
wireless but have used tethered. The times I have been around the
wireless, I was impressed at the performance.

"Grumman-581" <grumman581@DIE-SPAMMER-SCUM-gmail.com> wrote in message
news:5aehd2pgjqc4okak8c1src37kovkdhfcr4@4ax.com...
> On Tue, 08 Aug 2006 05:52:03 -0400, nitespark <nitespark@cox.net>
> wrote:
>> Actually, the units from OTS are SSB
>
> SSB implies AM type modulation... That's not to say that someone
> couldn't design something using FM type modulation, but for the most
> part, FM type modulation tend to be at higher frequencies and as such,
> they do not propagate through water as well as lower frequencies, thus
> the range would not be as good... VLF and ELF get very good
> propagation through water, but no one really wants to have to carry
> that long of an antenna around with them... <grin>


I am learning more all the time. Now if I could only find some used
equipment.

Chuck

"Grumman-581" <grumman581@DIE-SPAMMER-SCUM-gmail.com> wrote in message
news:5aehd2pgjqc4okak8c1src37kovkdhfcr4@4ax.com...
> On Tue, 08 Aug 2006 05:52:03 -0400, nitespark <nitespark@cox.net>
> wrote:
>> Actually, the units from OTS are SSB
>
> SSB implies AM type modulation... That's not to say that someone
> couldn't design something using FM type modulation, but for the most
> part, FM type modulation tend to be at higher frequencies and as such,
> they do not propagate through water as well as lower frequencies, thus
> the range would not be as good... VLF and ELF get very good
> propagation through water, but no one really wants to have to carry
> that long of an antenna around with them... <grin>


I am learning more all the time. Now if I could only find some used
equipment.

Chuck

On Tue, 8 Aug 2006 16:28:33 -0700, "r49miner" <nospamr49miner@cox.net>
wrote:
> I am learning more all the time. Now if I could only find some used
> equipment.

We're just give you enough information to confuse you to the point
where you won't be able to make a decision... Soon, you'll be saying
that ignorance was bliss... I'm kind of old fashioned, I like hard
wired connections... Preferably connected to a Mk-V helmet...

On Tue, 8 Aug 2006 16:28:33 -0700, "r49miner" <nospamr49miner@cox.net>
wrote:
> I am learning more all the time. Now if I could only find some used
> equipment.

We're just give you enough information to confuse you to the point
where you won't be able to make a decision... Soon, you'll be saying
that ignorance was bliss... I'm kind of old fashioned, I like hard
wired connections... Preferably connected to a Mk-V helmet...

"Grumman-581" <grumman581@DIE-SPAMMER-SCUM-gmail.com> wrote in message
news:ddlid2tl9hddjll340gld9no0loi5jeu8l@4ax.com...
> On Tue, 8 Aug 2006 16:28:33 -0700, "r49miner" <nospamr49miner@cox.net>
> wrote:
>> I am learning more all the time. Now if I could only find some used
>> equipment.
>
> We're just give you enough information to confuse you to the point
> where you won't be able to make a decision... Soon, you'll be saying
> that ignorance was bliss... I'm kind of old fashioned, I like hard
> wired connections... Preferably connected to a Mk-V helmet...

I think I will pass on your idea of a great dive with the Mk-V helmet. I
would feel claustrophobia right away, and I'm not planning on diving past 30
feet and only in rivers. What turns me on is being on the end of an 8"
suction gold dredge. Honest you can't confuse me anymore than I already am.

"Grumman-581" <grumman581@DIE-SPAMMER-SCUM-gmail.com> wrote in message
news:ddlid2tl9hddjll340gld9no0loi5jeu8l@4ax.com...
> On Tue, 8 Aug 2006 16:28:33 -0700, "r49miner" <nospamr49miner@cox.net>
> wrote:
>> I am learning more all the time. Now if I could only find some used
>> equipment.
>
> We're just give you enough information to confuse you to the point
> where you won't be able to make a decision... Soon, you'll be saying
> that ignorance was bliss... I'm kind of old fashioned, I like hard
> wired connections... Preferably connected to a Mk-V helmet...

I think I will pass on your idea of a great dive with the Mk-V helmet. I
would feel claustrophobia right away, and I'm not planning on diving past 30
feet and only in rivers. What turns me on is being on the end of an 8"
suction gold dredge. Honest you can't confuse me anymore than I already am.

On Tue, 8 Aug 2006 21:41:11 -0700, "r49miner" <nospamr49miner@cox.net>
wrote:
> I think I will pass on your idea of a great dive with the Mk-V helmet. I
> would feel claustrophobia right away, and I'm not planning on diving past 30
> feet and only in rivers. What turns me on is being on the end of an 8"
> suction gold dredge.

Odd are, you would make more money mowing lawns...

> Honest you can't confuse me anymore than I already am.

Thanks... I guess I can retire now with the satisfaction of knowing
that my mission is done...

On Tue, 8 Aug 2006 21:41:11 -0700, "r49miner" <nospamr49miner@cox.net>
wrote:
> I think I will pass on your idea of a great dive with the Mk-V helmet. I
> would feel claustrophobia right away, and I'm not planning on diving past 30
> feet and only in rivers. What turns me on is being on the end of an 8"
> suction gold dredge.

Odd are, you would make more money mowing lawns...

> Honest you can't confuse me anymore than I already am.

Thanks... I guess I can retire now with the satisfaction of knowing
that my mission is done...