Topics

Solar Cycle 24, 40-meter NVIS, and next year's JOTA

Jef - N5JEF
 

I've gotten great satisfaction working with the Scouts during the annual JOTA, but for me, the last JOTA was a (personal) disappointment due to the non-existent 40-meter NVIS propagation.  If I could have gotten a 40-meter antenna up about a half-wave (60-feet) above ground, it could have been fun operating skip, but we didn't have the structure for that, and with a 40-meter antenna only about 18 feet above the ground, most of the radiation was lost as it penetrated the very weak F-layer.  

That's not to say NVIS wasn't doable under these conditions, but it would have been on 60-meters with a suitable 60-meter antenna.  The Scouts wouldn't be on that band, but emergency communications would have been fine -- on 60-meters, with the right antenna.

Fortunately, the group had a good 20-meter antenna up about 30 feet, and that worked pretty well into New York and Saskatchewan, and the 2-meter repeater station was very popular with the kids (as was the CW station!)

Here's a chart of Solar Cycle 24, showing we're still near the bottom of an exceptionally poor cycle:

image.png

So what will I offer to bring and do for next year's JOTA?  It won't be 40-meter NVIS for a few more years.

  • I may have a large magnetic loop for 80/60/40 meters, providing good vertically polarized radiation even at low height above ground. That could be interesting.  I'd better get back to work on completing that project...

  • And it might be fun for the kids to have an array of two or four small microwave transceivers (5GHz) networked and sending audio.  They could talk to each other, and experiment with turning the antennas in azimuth and/or blocking or reflecting the beam.

  • Another option would be a demo of digital modes such as FSQ, Winlink, APRS...

Those are my thoughts for now.  Thanks to Orion for all his work organizing these JOTA events.

- Jef  N5JEF

Nathan Chilton - K6NDC
 

I like those ideas, Jeff! 

Another digital mode to consider would be MT63 2k Long.  I've played with it a little bit and it's incredibly simple and effective even without an interface cable  between the computer and the radio.  I used it to send messages between a Chromebook and an Android phone using HTs in different rooms of my house.  I think the kids would find it fascinating to hear the messages be converted to/from sound and transferred over the radio.  All we'd need is a couple of HTs and a couple of Android phones (or laptops/Chromebooks). 

I heard some people working this mode on a net a while back, on a repeater that didn't have a strong path to my home.  I couldn't always make out every word when they were speaking, but when they sent a form with MT63 2k Long, I received the full form without error.

Jef - N5JEF
 

Nathan -

I like the way you think!  :-)

- Jef

On Wed, Oct 23, 2019 at 10:33 AM Nathan Chilton - K6NDC <k6ndc@...> wrote:
I like those ideas, Jeff! 

Another digital mode to consider would be MT63 2k Long.  I've played with it a little bit and it's incredibly simple and effective even without an interface cable  between the computer and the radio.  I used it to send messages between a Chromebook and an Android phone using HTs in different rooms of my house.  I think the kids would find it fascinating to hear the messages be converted to/from sound and transferred over the radio.  All we'd need is a couple of HTs and a couple of Android phones (or laptops/Chromebooks). 

I heard some people working this mode on a net a while back, on a repeater that didn't have a strong path to my home.  I couldn't always make out every word when they were speaking, but when they sent a form with MT63 2k Long, I received the full form without error.

Greg D
 

Hi Jef,

Good thoughts.  I did have a small APRS demo, along with receiving a few satellite passes, but APRS is best demo'd with two people to exchange the messages between.  I was able to get the point of the mode across between the D74 and the laptop (when it was cooperating), and adding in some of the services (Fortune, weather, satellite pass predictions, email / SMS gateways, etc), but could definitely have used another station to communicate with.  Now that you've got your D74 configured, if you're not having luck with that loop, consider moseying over to my table...

Still, a good event overall. 

Greg  KO6TH


Jef - N5JEF wrote:

I've gotten great satisfaction working with the Scouts during the annual JOTA, but for me, the last JOTA was a (personal) disappointment due to the non-existent 40-meter NVIS propagation.  If I could have gotten a 40-meter antenna up about a half-wave (60-feet) above ground, it could have been fun operating skip, but we didn't have the structure for that, and with a 40-meter antenna only about 18 feet above the ground, most of the radiation was lost as it penetrated the very weak F-layer.  

That's not to say NVIS wasn't doable under these conditions, but it would have been on 60-meters with a suitable 60-meter antenna.  The Scouts wouldn't be on that band, but emergency communications would have been fine -- on 60-meters, with the right antenna.

Fortunately, the group had a good 20-meter antenna up about 30 feet, and that worked pretty well into New York and Saskatchewan, and the 2-meter repeater station was very popular with the kids (as was the CW station!)

Here's a chart of Solar Cycle 24, showing we're still near the bottom of an exceptionally poor cycle:

image.png

So what will I offer to bring and do for next year's JOTA?  It won't be 40-meter NVIS for a few more years.

  • I may have a large magnetic loop for 80/60/40 meters, providing good vertically polarized radiation even at low height above ground. That could be interesting.  I'd better get back to work on completing that project...

  • And it might be fun for the kids to have an array of two or four small microwave transceivers (5GHz) networked and sending audio.  They could talk to each other, and experiment with turning the antennas in azimuth and/or blocking or reflecting the beam.

  • Another option would be a demo of digital modes such as FSQ, Winlink, APRS...

Those are my thoughts for now.  Thanks to Orion for all his work organizing these JOTA events.

- Jef  N5JEF

Nathan Chilton - K6NDC
 

Greg, 

I should have mentioned that I had a Yaesu FT3DR with me.  We could have exchanged APRS messages between our HTs!
 

Greg D
 

Thanks, Nathan.  But you were quite busy on 20 with the site up in Canada, and they were doing a lot better getting kids on the air than I would have ever been.

What I probably should have done was to find a somewhat more local station on HF or VHF and have the kids make voice contacts from my car...

Greg  KO6TH


Nathan Chilton - K6NDC wrote:

Greg, 

I should have mentioned that I had a Yaesu FT3DR with me.  We could have exchanged APRS messages between our HTs!
 

Nathan Chilton - K6NDC
 

Yes, I was fairly busy on 20.  It was a lot of fun to connect these scouts with other scouts in Canada over the radio.  It was also a lot of fun for me personally, because it was actually my first time operating on HF (other than operating PSK31/FT8), my first time operating SSB, and my first international contacts (not counting the time at the last field day when Brian set everything up and passed me the mic -- which was also a fun experience).  

Michael - N6MRP
 

Hello All,

I was on my 2m Yaesu FT-2900. The key to getting numerous contacts was bouncing around the many repeater frequencies programmed into the radio. Several of the hams responding had been Scouts themselves.

73

Mike KK6GLP

On Wed, Oct 23, 2019 at 1:59 PM Greg D <ko6th.greg@...> wrote:
Thanks, Nathan.  But you were quite busy on 20 with the site up in Canada, and they were doing a lot better getting kids on the air than I would have ever been.

What I probably should have done was to find a somewhat more local station on HF or VHF and have the kids make voice contacts from my car...

Greg  KO6TH


Nathan Chilton - K6NDC wrote:
Greg, 

I should have mentioned that I had a Yaesu FT3DR with me.  We could have exchanged APRS messages between our HTs!
 

Gary - KC3PO
 
Edited

Interesting... we seemed to have 40m NVIS working OK during Field Day. Bummer. 

- Gary

On Wed, Oct 23, 2019 at 9:02 AM Jef - N5JEF <jef@...> wrote:
I've gotten great satisfaction working with the Scouts during the annual JOTA, but for me, the last JOTA was a (personal) disappointment due to the non-existent 40-meter NVIS propagation.  If I could have gotten a 40-meter antenna up about a half-wave (60-feet) above ground, it could have been fun operating skip, but we didn't have the structure for that, and with a 40-meter antenna only about 18 feet above the ground, most of the radiation was lost as it penetrated the very weak F-layer.  

That's not to say NVIS wasn't doable under these conditions, but it would have been on 60-meters with a suitable 60-meter antenna.  The Scouts wouldn't be on that band, but emergency communications would have been fine -- on 60-meters, with the right antenna.

Fortunately, the group had a good 20-meter antenna up about 30 feet, and that worked pretty well into New York and Saskatchewan, and the 2-meter repeater station was very popular with the kids (as was the CW station!)

Here's a chart of Solar Cycle 24, showing we're still near the bottom of an exceptionally poor cycle:



So what will I offer to bring and do for next year's JOTA?  It won't be 40-meter NVIS for a few more years.

  • I may have a large magnetic loop for 80/60/40 meters, providing good vertically polarized radiation even at low height above ground. That could be interesting.  I'd better get back to work on completing that project...

  • And it might be fun for the kids to have an array of two or four small microwave transceivers (5GHz) networked and sending audio.  They could talk to each other, and experiment with turning the antennas in azimuth and/or blocking or reflecting the beam.

  • Another option would be a demo of digital modes such as FSQ, Winlink, APRS...

Those are my thoughts for now.  Thanks to Orion for all his work organizing these JOTA events.

- Jef  N5JEF

Jef - N5JEF
 

Gary -

How high was (the center of) your antenna at Field Day?  I would guess you had it up high to make as many contacts as possible.

- Jef

On Wed, Oct 23, 2019 at 11:12 PM Gary Frerking <gfrerking@...> wrote:
Interesting... we seemed to have 40m NVIS working OK during Field Day. Bummer. 

- Gary