(meteorobs) Re: My radio meteor problem

[Mark Steven Williams]

Michael,

83.25 is the primary video carrier frequency for TV channel 6 in North 
America. The NTSC standard (TV system in North America) and more importantly 
the American FCC and Canadian telecommunications authority (the agency's 
name escapes me at the moment) also specify 10 khz video carrier offsets in 
an effort to reduce video interference between stations when the bands open 
up and "skip" conditions are present. Keeping everybody on Channel 2 off the 
same video carrier frequencies mitigates this somewhat.

I did a quck check of my WRTH (World Radio Television Handbook) and, because 
of the number of TV stations they don't present a city by city listing of TV 
stations. I am a bit confused about your comment about your filter only 
eliminating the "noise" on 83.25. If you have a Channel 6 locally, Channel 6 
is about the LAST place you want to be monitoring meteor bursts. I don't 
have a channel by channel listing for you there in Halifax and don't have 
the time right now to check the FCC media database.

The way to monitor TV video carrier frequencies is by listening on a TV 
channel which is not occupied by a local station. Here in my location, near 
Louisville, KY, we have a station operating on Channel 3. So, I usually 
monitor the video carrier frequency of Channel 2.

Maybe you will find this helpful. Here are the video carrier frequencies for 
the lowband VHF TV stations in North America.

(Ch 2) 55.25, (Ch 3) 61.75 (Ch 4) 67.25 (Ch 5) 77.25 and (Ch 6) 83.25

Again, each Channel has +/- offsets, therefore on 2 you will find carriers 
at 55.24, 55.25 and 55.26. Usually here I can hear the video carrier from 2 
in Dayton fairly strongly on 55.26 (working from memory again) on 
groundwave. So, I listen on 55.24.

I am curious about the radio you are using. What one really needs to do this 
is a "communications" receiver (I use a ham transceiver) capable of 
receiving "CW" (morse code) mode. In CW mode continouous carriers present as 
a constant tone. Most bursts in this mode also present a bit of doppler 
shift depending on whether the pebble falls toward or away from the 
direction of the transmitter. The doppler bursts present interesting 
frequency shifts depending on the speed of the meteor. An FM scanner really 
isn't ideally suited for this sort of work.

Tell me about your setup there...and don't go off grumbling in the night 
like I do. I had this very discussion with my engineering peers at the radio 
stations the other day. They think I'm a relic..

Regards,

MSW
Mark S. Williams
K9GX
Elizabeth, IN
k9gx at n4gn.com

----- Original Message ----- 
From: "Michael Boschat" <aa063 at chebucto.ns.ca>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: Tuesday, June 27, 2006 11:20 AM
Subject: (meteorobs) Re: My radio meteor problem


> Hi:
>
> Basically, I will be crap out of luck in 2009 because of this screwing 
> around of
> the carrier? Bad enough that light pollution and new building being built 
> screw my
> sky now my radio eyes are gone. Also bad enough the stupid time change now
> for November...I'm setting my clocks back in Oct not Nov.
>
> The filter I have will only eliminate the noise of Ch.6 ( 83.25 MHz ), I 
> use the
> minus off set at 83.24 MHz. The radio can go to Ch.2 but the filter will 
> be at it's
> limit of tuning for that frequency.
>
> I get too much noise on 50MHz so that is out....FM radio is too crowded 
> here in
> Halifax with overlap.
>
> Is there any frequency left to do meteor scatter?  or do I just hang up my 
> antenna
> and radio in 2009?
>
> -- 
> Clear skies
> ===========
> Michael Boschat
> Royal Astronomical Society of Canada - Halifax Center Astronomy page: 
> http://www.chebucto.ns.ca/~aa063
> ---
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