RF-Seismograph did not record any changes in the popagation

Cool. I will do that when I get home today.

 

You are correct I forgot to square the radius of the circle. I had it done right on paper and then I forgot doing it.

So the equation becomes: 50km exp2 * Pi = which is 7854km exp2.

Divided this by half of the surface of the earth is: 255.05 * 10 exp6 /7854 = 31 * 10 exp-5

This is still a pretty small change!!!


The sun takes up about 0.5deg of the sky. This is too small to point a HF antenna to it. It is physically not possible to build an antenna for HF that has the capability to concentrate HF so you only hit only the moon during the eclipse. (This is why we use 2m and 70cm for moon-bounce and not HF)
Also the change in plasma density is so small that the bending effect of the ion layers does not yield any measurable effects in the HF band.

The RF - Seismograph is totally capable of measuring propagation in the HF region of space. It has been doing so for the past year and it has recorded some interesting phenomena.
Also it has recorded nighttime propagation just prior to the eclipse on both instruments running that day. But maybe your right, in order to the change you need a several 100million setup like the big radio telescopes from NASA that operate on GHz range.

The question we wanted to answer was if it affects HF. And there is very little hard evidence that it does. All the measurements and the physics are all over the place when it comes to HAM observation as you can see in this post.

Believe me it was a surprise to me too... but sometimes it becomes necessary to look at the facts and move on.

Alex - VE7DXW

 

You have no doubt heard the term "confirmation bias" in your scientific travels? I would submit that the obverse can also be be strongly operative too (i.e. "non-confirmation bias")

What you seem to be seeking is undeniable, irrefutable, stark, contrasting "data" upon which to base a "call". Many times in life, as in physics, "you have to work with the data you have been given." Or took, as on a non-easily-repeated 'experiment' or event such as we just went through.

Have you looked at any of the radiosonde data that is publicly available?

de Jim

 

Hi Jim;

The people of HAMSci.org are compiling all the data and they will have this available to them.

I am also interested to see their data. Would be interesting to see how much of the bands actually chanced during the eclipse.
It takes the moon approx. 2.5h to go passed the sun and if the radiosondes picked it up it would have a delayed peak corresponding with the eclipse.

I will ask HAMSci if they have radiosonde data that they can release.

Thank you for you input;

Alex

 

Radiosondes are for tropospheric weather. Ionosondes measure the ionosphere.

Here is a summary I made using uncooperative oblique observations of a vertical sounder in the penumbra (the big area of partial eclipse) that clearly shows the effect. The sounder sweeps continuously from 2 to 20 MHz every 12 minutes. If we focus on the left part of this plot (frequencies less than 8 MHz or so), the yellow blob represents the region between the minimum and maximum frequencies at which the sounding was detected. So, it basically bounds the maximum and lowest usable frequencies for the link (MUF and LUF).

The inset map at the upper right shows the geography of the link overlaid on the NASA eclipse map. The umbra passes through between 14:40 and 15:00 EDT or 18:40 and 19:00 UTC. What happens at that time on my MUF/LUF plot? The LUF sags a little bit corresponding to decreased D-region absorption and the MUF goes way down due to recombination of the F region. After the eclipse passes, it comes back. This is consistent with the logs and informal anecdotes of many hams as well as the physical explanation I outlined in my previous post.

Please explain to me how this isn't an observable effect.

The receiver was an Ettus Research USRP N210 with the internal GPSDO option and I was running my (slightly) modified version of this open-source software:

http://www.sgo.fi/~j/gnu_chirp_sounder/

The antenna was my 40-meter dipole.

 

Just to put some info in the pool, I took my Yacht Boy 400 to the eclipse. I programmed the channel buttons to clear channel AM stations from a list on the web. Early, at the eclipse event, I scanned through all 40 channels and deleted those I could hear before the eclipse and then scanned through the channels at totality. I found 4 stations that could be heard for just a few minutes. I was more interested in sharing the event with my grandson than I was in getting data so no numbers but the reception lasted just a few minutes. A couple minutes after the totality, they were gone. I was in the Willamette Valley in Oregon so I could only get station from the east. There are very few clear channel stations floating in the Pacific and I never heard Hawaii. After the event, I gave the Yacht Boy 400 to my grandson who now is interested in radio. A month ago he saw me working cw for the first time. If I am lucky, I got him interested in ham radio.

 

Thank you for the Graphics.

I did not say there was no measurable effect I stated that propagation did not change much as a result of it.

Does the high solar activity that we experienced show up in the Ionosonde? How?

The RF-Seismograph shows the same behavior in the morning. The nigh time propagation disappears after sunrise as the absorption layer builds. Since there is a high radiation level the propagation even from 40m.

See below:

 

Oh aren't YOU cute! Taking us back to grade-school defs WHEN the appropriate term is more like "rawinsonde" for what you want to describe ... nevertheless "radio sounding" is still an appro label for "sounding" using radio, as in "determine the height and other characteristics of some components of the atmosphere using RADIO techniques."

IF you are interested, I have a massive number of links to the Lowell Digisonde-256 AND the DPS-4D ionospheric sounder info, including both tech and operations manuals, right here on my WB5WPA QRZ page ... you would therefore THINK I knew the diff BTW an ionosonde, a rawinsonde and have some idea about 'radio sounding' in general.

On my webpage is also a link to the master station list of all past and present operational Lowell Digisonde sites.

BTW, Google Chrome natively 'corrects' ionosonde to radiosonde ...

de Jim

 

A few have worked or heard partials of EME on 10M and 6m is rather common.

 

*/

6m and 10n antennas for moon bounce are monsters if it is even possible. How much power are they running?

How do they know it was the moon and not the ionosphere?

Alex

 

For 6m EME, check out the web page of Lance W7GJ (link below) Note the PORTABLE 6m EME DX'peditions.

http://www.bigskyspaces.com/w7gj/

How do you know it's the moon? Context of any iono activity, direction of antenna, distance of DX, and most of all, propagation delay.

If you press PTT and say "Hello moon", release, and then hear yourself reply, "Hello moon", its a pretty good assumption, eh?

Xmtr gain, ie, high QRO, $/watt, is relatively reasonable on 50 MHz now. And combined with the receive "gain" of JT modes have really opened up the possibilities for small footprint EME operations.

73 de John WØPV

 

According to Psk Reporter my 40 meters JT65 signal was received on the west coast from Indiana during the 85% or so totality. That is something is normally impossible at 12:30PM local time. I would say that is a HUGE change in 40 meters propogation. I operated for about 2 hours and while I never received any west coast stations they were receiving me for about 30 minutes before we hit our 87% but not for long after. It was fun experimenting with my favorite band and mode while participating in the SEQP.

 

Noticed no unusual propagation on 80/40 meters at this location.

 

Ive heard my own echos (decent copy too) on 6M with a single HB 8 el (13 dBi and very high F/R) on a 36' boom pointed at the horizon for moon rise which is at a minus 3 degrees elevation on this hilltop. Power is 1200W. The added benefit is a good 10dB+ of ground gain. One guy travels the world with a single long boom antenna; others give it a shot on various DXpeditions and are often successful. All use standard 1200-1500W commercial amps. Some use a 4 bay of long booms from home, M Squared is the usual choice.

Horizon shots are used on 10M also but I never tried it when I had the HB 4/4/4/4 up during my contesting days.

Software tells the distance, path loss, and time to hear the echo. There is a slim to none chance it was anything but EME. The military was doing EME as far back as the late 40's with only up to 10KW back when the best noise figure was in double digits. My system NF is about .5dB from 50-1296 mHz.

 

Those marine BCB radios are fantastic.. I have a working Gemtronics unit with an auto-nulling, auto-rotating ferrite antenna on top as well. Thanks for posting. 73 , Eric n6spp