The www.WAVEFINDER.ch is the first really efficient MOB retrieval
system available on the market for less than 2000 Euros.

This product has some new features making it really more efficient
than its competitors like SeaMarshall or VECTA2:

- operating range up to more than 10nm
- fully waterproof (beacon, antenna and display)
- small transmitter carried at the belt (less than 130 gr)
- no need to pay a license, it makes use of a free ISM band (869 MHz)

If you want more information, go on the web site, you will find a lot
more information and you will be able to download the complete user
manuals.

If you have other questions, feel free to contact , or
ask on the newsgroup.

Wow....a single-function device for only $2200! Why so much?

A VHF DF is about $400, tops. A VHF walkie talkie is about $250 and
can be otherwise very useful. $2200 is a ripoff, even for the rich.

10nm is a LONG way for a low powered, 800 Mhz signal to make the trip.
For comparison, try to get 10nm from a 180' tall cellular phone tower
with a 200mw digital cellphone and make a call. The range in the BEST
conditions with NO obstructions (like conductive waves between the
transmitter and MOB) is about 2 miles. Isn't 10nm stretching things a
bit....like a factor of FIVE? How many watts does this transmitter
run? My line-of-sight calculations from a transmitter at arms length
above the ocean surface to a receiver above the ocean at 40' is about
2, maybe 3 miles at best. What's it reflect off to get 10nm?

Caveat Emptor buyers.....



On 25 Aug 2003 01:15:56 -0700, (Patrick) wrote:

The www.WAVEFINDER.ch is the first really efficient MOB retrieval
system available on the market for less than 2000 Euros.

This product has some new features making it really more efficient
than its competitors like SeaMarshall or VECTA2:

- operating range up to more than 10nm
- fully waterproof (beacon, antenna and display)
- small transmitter carried at the belt (less than 130 gr)
- no need to pay a license, it makes use of a free ISM band (869 MHz)

If you want more information, go on the web site, you will find a lot
more information and you will be able to download the complete user
manuals.

If you have other questions, feel free to contact , or
ask on the newsgroup.


Larry W4CSC

Maybe we could get the power grid fixed if every politician
regulating the power companies wasn't on their payrolls.

On 26 Aug 2003 23:26:16 -0700, (Patrick) wrote:

Hello Larry,

You are not completely wrong, if every crew member own at any time a
waterproof VHF radio and a GPS, you have a good solution to the MOB
problem, but the boat VHF has to be turned on and the other crew
members have to be awake.

The size of the package you have to carry will be really not pleasant
!!

Concerning the range, the transmitter has a 500mW ERP power. The
receiver has a bandwith of only 1 Hz, with a 8th order filter !!! The
resulting sensitivity is better than -127dBm.
This high sensitivity is furthermore improved by a strong digital
signal processing.

I have an 8-pole CW filter of 250 Hz with about 60db/octave sides on
it in my Yaesu FT-990AC transceiver. How do you get the bandwidth to
1 hz? If you had 10 identical crystals in a row you'd never reach 1
Hz! Is this the IF bandwidth or some digital trick to make it LOOK
like a 1 Hz BW?

As to the 127 dBm receiver sensitivity, that might work great in deep
space, but I live on planet EARTH. The noise from the sun, thermal
noise from every surface Sun beats on is higher than that.

The propagation on a sea is absolutely not completely guided by the
line of sight rules, in fact, you have a big refraction factor on the
top of the waves. The measurements we have achieved have always been
better in strong sea conditions.


No matter....500mw ERP isn't going 10 miles except maybe in space if
you have a big enough dish to collect enough energy cryogenically
cooled.....



Larry W4CSC

Isn't it becoming more practical by the day to make
Iraq's desert the new World Nuclear Waste Disposal Site?

No matter....500mw ERP isn't going 10 miles except maybe in space if
you have a big enough dish to collect enough energy cryogenically
cooled.....



I thought that too as an EE, but you'd be very surprised what UHF dx you can
get at sea under certain conditions. On flat calm glassy slick days I have seen
handheld FRS radios go MORE than 10 miles. It seems to have something to do
with sea surface conditions. I dont understand it, but its real. Gordon West
wrote about it in reviewing an early MOB device that had really low power.