Topics

ATV coordination

Mark Conner <n9xtn@...>
 

I received the following from Mike W5VSI of EOSS:

Re ATV on 434 and 439 MHz: remember that if these are NTSC AM
sigs,
they have sidebands running out to +/- 6 MHz around the carrier
freq.
Thus the 434 USB will go out to 440 Mhz, and the 439 LSB will go
down to 433 MHz. Although the video bandwidth may be pretty puny
at the extreme edges of the sidebands, the audio and chroma
subcarriers of 4.5 and 3.58 MHz will also appear in both
sidebands.
Since each ATV signal occupies 12 MHz, the minimum carrier
separation
to avoid adjacent channel QRM is 12 MHz. So two ATV sigs will
occupy
24 MHz inside a 30 MHz-wide ham band, and that's why I don't plan
on bringing out ATV.

For WB8ELK and KD0FW - can you separate your carrier frequencies
some more, or should we just fly it as is and see what we get? I
don't have any experience with ATV to have a feel for how badly
this will affect us.

73 de Mark N9XTN

Bill Brown
 

There will be some interference with strong signals from the two balloons at
434 and 439.25 MHz, but probably not too bad when they get weaker,
particularly if the two balloons seperate a bit during the flight (different
ascent rates will help out here).....it will be interesting and folks will
have lots of multi-channel ATV to watch on Saturday.

73s de Bill WB8ELK

Michael L. Bogard <kd0fw@...>
 

I would think that a few miles of separation and that I will be horizontal polarized would have some effect on the out come. I think that it would be great to see three video signals all on at the same time in the band. If we don't try it we will never know for sure.

Mark Conner <n9xtn@...>
 

I agree, if the choice is fly it this way or don't fly it, let's put it
in the air and see what happens.

73 de Mark N9XTN

----- Original Message -----
From: wb8elk@...
Date: Friday, June 28, 2002 1:02 am
Subject: Re: [GPSL] ATV coordination

There will be some interference with strong signals from the two
balloons at
434 and 439.25 MHz, but probably not too bad when they get weaker,
particularly if the two balloons seperate a bit during the flight
(different
ascent rates will help out here).....it will be interesting and
folks will
have lots of multi-channel ATV to watch on Saturday.

73s de Bill WB8ELK


------------------------ Yahoo! Groups Sponsor --------------------
-~-->
Free $5 Love Reading
Risk Free!
http://us.click.yahoo.com/3PCXaC/PfREAA/Ey.GAA/ELTolB/TM
-------------------------------------------------------------------
--~->

To unsubscribe from this group, send an email to:
GPSL-unsubscribe@...



Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/