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80 meters propagation

Sep 18th 2015, 00:29

W7LUU

Joined: Jun 26th 2012, 02:16
Total Topics: 0
Total Posts: 0
Ladies & Gents: Art Bell was talking with another ham the other day and both supported each other in a 80 meters propagation claim. The claim was that the 80 meters propagation today is dramatically different than years past. That it used to be there was some reliability in the expectations between day/night and seasonal summer/winter conditions. Today, propagation is so unreliable with expected band conditions that it is believed that "something strange is going on with the band". It was suggested some of the high--power, high frequency, ionosphere experiments in Alaska have altered the conditions beyond anything a veteran 80 meter operator might expect previously. Can anyone out there comment on their experiences to confirm, deny, or offer comments? Could be very interesting. W7LUU


Sep 18th 2015, 13:43

W1VT

Joined: Apr 4th 1998, 00:00
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Total Posts: 0

It is easier to see the seasonal variations if you don't restrict yourself to one band.
http://www.eham.net/ehamforum/smf/index.php?topic=104778.0
Here is a lengthy thread on eham.net that shows that the summer doldrums is alive and well. I'd get about 2 phone calls a week about the summer doldrums--one fellow even sent his radio back to Kenwood thinking it was broken.

Normally, I can work Europe and California on 80M JT65 a few hours after sunset. Last night I worked California. But, I was distracted by E6GG, who I worked on 17, 20 and 30 meters. Since 160 finally opened to Europe the day before--working I2TOA on CW, I worked IK4ADE and F5RRS on JT65.

I haven't done the calculations, but I'd expect the total power used by the ionospheric experiments to be miniscule compared to the high power shortwave broadcast transmitters that used to be on the air when I was a kid.

It is likely that the biggest differences are the antennas and interference situation--fewer hams can put up the antennas needed for a good 80 meter signal. Even fewer can hear well with all the noise from electrical and electronic devices.

http://www.arrl.org/news/haarp-facility-shuts-down
http://www.valdezstar.net/story/2015/09/02/main-news/new-management-haarp-again-open-for-business/969.html
Here is some background on the high energy ionospheric experimentation.

Zack W1VT
ARRL Senior Lab Engineer
Sep 18th 2015, 21:46

W7LUU

Joined: Jun 26th 2012, 02:16
Total Topics: 0
Total Posts: 0
Hi Zack and thanks for the reply and links. The operative sentence is "The claim was that the 80 meters propagation today is dramatically different than years past." I've been a ham for 50+ years so I know about propagation on other bands and about HAARP. So more pointedly, thinking back 10 or 15 years ago, is the 80 meter band subjectively different in propagation than 10 or 15 years ago. I remember there was some predictability, others say its not anymore.
Sep 19th 2015, 08:40

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I was recovering from a stroke and couldn't get on 80M 10 or 15 years ago.
While I've made over 4000 contacts on 80M in the last few years, it isn't terribly objective--most of the contacts were made when I expected to make them. After the gray line opening to Australia in the morning I typically turned the radio off or went to another band. What you may want to do is to analyze data collected by spotting networks, such as the reverse beacon network.

You may find that predictability to be a function of antennas/power--a bigger station may reliably get into a spotting network, while a smaller station,perhaps running a few watts to a compromise antenna, will rarely show up. When I first got on 80M, running a few watts to a dipole, propagation to Europe and the Caribbean was very difficult. Now, with a top loaded vertical and 600 watts, such making such contacts are quite easy--I've worked over 150 countries with 100 watts in the past few years. The 600W amp wasn't purchased for working DX--it was to help out stations who couldn't hear my 100W in the ARRL Centennial Celebration.

The biggest change may be the expectations of the operators--folks look at spotting clusters and JT65 signal reports and wonder "why can't I have that," even though they are using heavily compromised antenna--their all band dipole may have common mode issues from not using a balun optimized for 80 meters. The may not even have a balun to save a few bucks. A lot of 80M DX comes in when it isn't convenient for the average operator to get on--dinner time, European Sunrise, and breakfast--many hams won't get on that that time even if you tell that they need to in order to work the DX.

Many people would find the idea of fixing a golf swing by buying a new club every week laughable--but, you actually do see the same sort of thing in amateur radio--folks are looking to improve their operating with minor improvements in hardware--when that time would be better spent actually listening on the air and training their ears to hear the stations. This is may be the case on 80 meters where the signals are there, but not as loud or easy to hear as on the higher bands. I decided to work on my DX awards before I got too old--I can still do things like move my 20M dipole in 15 minutes to a different set of trees to work Comoros on 20 CW.

Zack W1VT


Sep 19th 2015, 23:54

W1VT

Joined: Apr 4th 1998, 00:00
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Total Posts: 0
80M is open to Europe on JT65 with my 40' high top loaded vertical
F5LMI -15 2326Z
G3VGZ -8 2346Z
OM0AST -19 2336Z
Zack W1VT
Sep 22nd 2015, 13:39

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Is VOACAP useful for predicting 80M propagation?
K6TU.com is providing free predictions for the E6GG operation based on your antenna and location.

Signal Strength Time (UTC)
S3 05-07Z
S6 07-10Z
S3 10Z-11Z
I worked them at 0646Z on 80M CW. By 07Z they had a pretty good signal that was easy to copy.

Zack W1VT
Mar 16th 2016, 13:47

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
It can be useful to watch the JT65 waterfall at 3.576MHz. There are some stations that can easily work Europe night after night, even though other stations can't hear the Europeans. The site hamspots.net can provide reception reports to see what stations can and cannot hear. You can also watch stations that put out good signals but for whatever reason can't hear any of the stations that are calling them.

Zack W1VT

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