20 meters during the morning and mid-day hours question

[steve_qix]

Hi !

I don't have any experience with 20 meters, but how reliable is 20 meters during the morning (about 8:30 Eastern time) to about 3:00PM Eastern for working G.B.?

This would be part of a scientific experiment associated with a local school.  We would need to send a signal to G.B. during the school day.

Any information would be much appreciated !

Thanks and Regards,

Steve

[Pete, WA2CWA]

Simple to do. Tomorrow and/or mid day, check this link:
http://www.dxmaps.com/spots/map.php?Lan=E&Frec=14&ML=M&Map=W2L&DXC=N&HF=S&GL=N
It's in real time.

[SM6OID]

Hi!

You can use this tool to make predictions, but remember it is only a prediction.
Actual propagation can be al lot different...
http://www.voacap.com/prediction.html

[W1RKW]

my experience with 20m in that time frame has been good.  Not consistent but more so than 10m by far.

[Ralph W3GL]

Hey Steve,

This is off topic but for some reason my confuser has deleted my ability here to start a new topic.   

Did I miss something or what happened to the 2014 AMTR results?

Thanks,

Ralph...

[K4RT]

Steve,

Good luck with your experiment. Good to hear you will be exposing students to ham radio.

Just a thought: In case 20M propagation is in the dumpster you might want to have a Plan B (if appropriate) such as alternative bands or demonstrating ham radio generally for your students ... perhaps QSOs with other DX, stateside, different modes, etc.

73,
Brad

[steve_qix]

This is more of a physics experiment than specific ham radio.  The goal is to measure, with a reasonable degree of accuracy, how long it takes for a radio signal to go from a specific location in the U.S., across the "pond" to G.B.

[K1JJ]

This is more of a physics experiment than specific ham radio.  The goal is to measure, with a reasonable degree of accuracy, how long it takes for a radio signal to go from a specific location in the U.S., across the "pond" to G.B.

I'll save ya the trouble....  

It will take about 21.5 milliseconds to travel from the east coast to the UK.  (Based on 4,000 miles distance at  186,000 miles / second)

Actually measuring it will be an interesting challenge, however. How do they intend to do it, with a GPS time reference and trigger of some kind?

T

[WD8BIL]

The velocity factor of pure air is something like .99995. It's probably something less in real life with humidity, altitude, pollution and any other variable you can add.

[KL7OF]

You should try to bounce off the moon....you could hear your own signal and time it easily...Gud Luk

[steve_qix]

This is more of a physics experiment than specific ham radio.  The goal is to measure, with a reasonable degree of accuracy, how long it takes for a radio signal to go from a specific location in the U.S., across the "pond" to G.B.

I'll save ya the trouble....  

It will take about 21.5 milliseconds to travel from the east coast to the UK.  (Based on 4,000 miles distance at  186,000 miles / second)

Actually measuring it will be an interesting challenge, however. How do they intend to do it, with a GPS time reference and trigger of some kind?

T

Right!  We know how to calculate it, but it's another thing to prove it    That's the whole idea - to prove it and also to get accurate measurements.  GPS is probably the most practical way to measure absolute time without spending a fortune.

[W1RKW]

Steve,
This is a very curious, intriguing and interesting experiment. Back in the 18th century, I think, the speed of light measurements were done over approximately 5 miles with rotating mirrors and were line of sight. the rotating mirrors introduced a constant/variable that allowed for the time/distance calculation.  How will you account for distance over the pond? It's not a direct path and will probably vary to some extent on atmospherics. How will you determine time for sent and received or returned signal?  This is a cool experiment.

[Pete, WA2CWA]

Propagation time delays between two locations can be quite variable and are probably dependent on a number of atmospheric anomalies at any time of day. One probably also has to consider the angle(s) of incidence into a specific atmospheric layer(s) and the angle of refraction on the receiving end.

[AJ1G]

Hopefully you will have no/minimal digital signal processing in the signal path end to end to throw in timing errors,

Would be interested in seeing details of the experiment and how it comes out.