(meteorobs) Question - radio meteor

Samuel Barricklow k5kj at mac.com
Tue May 6 09:19:28 EDT 2014


Paul,

I don’t believe that AM would be the optimum mode.  If you were to use AM, you would need to be able to sense signal strength, and set a threshold for tripping a counter.  USB tuned 1 kHz below the transmit frequency is best for me.  A 1 kHz tone, plus or minus doppler shift, is produced.  Tone frequency varies depending on the signal source, because the transmitters apparently aren’t calibrated exactly.  Note that three analog video carrier frequencies are used.

55.239 MHz
55.249 MHz
55.259 MHz

Pings are audible on all three frequencies here in the Dallas area.  I’m using a 2 element wire yogi pointed straight up.  My 3 element 6 meter horizontally polarized yogi mounted at 60 feet AGL, works well also.  

Multiple signal sources are present, including Mexico, and from within the U.S. located somewhere to the northeast and northwest from Dallas. 

I’ve considered using an omni-directional amplified antenna from Radio Shack that was designed for use on RVs.  Unlike most of the new “HD” antennas, it covered the low VHF channels.  I may experiment with it when time permits.

73,
Sam - K5KJ

On May 6, 2014, at 6:15 AM, Paul Goelz <pgoelz at comcast.net> wrote:

> At 08:51 PM 5/5/2014, you wrote:
>> I switched from USB to AM for a couple hours tonight while monitoring
>> via spectrogram on 55.250 MHz just out of curiosity.  On USB, there
>> were few.... but some.... meteors.  On AM I got zero meteors.  I'll
>> leave it on AM overnight and see what it looks like in the morning,
>> when the count is usually much higher.  But in my brief experiment so
>> far, USB vastly outperforms AM when examining the results with a spectrogram.
>> 
>> Paul
> 



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