Trials & Errors #67: Defending the Spectrum

This is the forum discussion for issue #67, and the discussion with David Siddall about how the League deals with Spectrum Defense. Do you have questions for either the author or K3ZJ? Post your comments or concerns under this thread please, and thanks for reading T&E! Dave Jensen, W7DGJ

 

My feeling about the situation of spectrum defense is that things are a little more complex than our organisations or the decade old texts of the ITU present them. Moreover, the situation is very different depending on the frequency bands.

We can use a SDR to look at the bands activity (or head to the entire day display of the University Twente for decametric waves here websdr.ewi.utwente.nl:8901/fullday/ ) and we find out that:
-decametric bands have large underused sections and that even in the used sections like broadcast, there appears to be space left. This is the consequence of short wave broadcast going out of fashion and stations relocating transmitters in countries next to their listeners. Interestingly, the amateur bands appear to be amongst the busiest, but that is rarely with experimentation but contests and FT8.
-metric bands also have large underused sections, except local broadcast radio and TV and, higher up, cellular phone.
-going up over 1GHz to the decimetric and centimetric bands (my SDR does not go higher), shows basically the same picture.

So, basically, over 30 MHz, we see what appears to be empty space and then the blocs of digital transmissions (digital TV and cell phones, Wi-Fi...) filling their allocated channel. There are a few other signals, obviously, but not that many.

Then, the concept of interference changed in the past decades. Physics did not change, obviously, but digital modulation has become very resistant for interference, as a look at the 2.4 GHz WiFi/Bluetooth/Microwave band shows. Sure, you get less throughput when the band is congested (physics still rules), but the end users do not notice.

Last but not least, broadcast is becoming a thing of the past. Most of Europe switched off long and medium wave transmissions. FM radio is supposed to be transitioned to DAB, but private stations don't want to pay the associated costs and some are simply closing. In Germany private TV stations rejected the change to change to DVB-T2, stating that the cost/benefit was unfavorable (there is actually an offer, but it requires a subscription and does not cover the whole country). Why is that so? The reason is quite simple: people with a bit of money all have cable and Internet (and a subscription to services like Netflix...), therefore the people who must use broadcast are, generally speaking, poor. Private radio and TV stations are financed by advertisement and marketing is not interested in users with no money.

 

By pure chance, I was presented about the following article about shortwave (decametric) broadcast today:
https://www.radioworld.com/columns-and-views/guest-commentaries/why-we-need-shortwave-2-0

 

Hi Jerome, that article is a great read, thank you! It is so true that "radiograms" (text from Shortwave 2.0 radios) could be a wonderful addition to areas of the world that aren't getting the news. Especially in war torn regions where the Govt does not want the populace to be getting certain information. Thanks for the link, Dave W7DGJ

 

Hi Dave,

The concept of spectrum defence, in my opinion, has shifted from actual practicality on what would be of benefit to all to who has the most money to buy a portion of it. I liken it to real estate. Some major companies buy huge swaths of land that they may not use for a bit or think they may use, then they either sit on it, sell it off for profit or actually use it. In either case it is tied up and the same can be said for radio spectrum. In America, the 1.25 M band is a good example as mentioned in your article. And why are portions of the 800 MC band still illegal in the US? My understanding is that was done years ago when mobile phones were analogue, but that band is pretty void nowadays, so how about putting it to use?

Regulators, it seems, really do not care as much about the users (like they used to), such as AR, as they do about the money a piece of radio "real estate" will bring in, which cellular and television companies, for example, have in abundance. Any organisation involved in spectrum defence has to contend with that. Another example is the push by telly broadcasters to shift from ATSC 1.0 to 3.0, which would essentially kill off ota television for many. For one, you would need an internet connected telly to decode the ota transmissions, they call it "DRM encryption". Try that in a rural state where there are a lot of places with limited or no internet and peeps rely upon current ota broadcast standards.

My apologies, I know all that sounds a bit cynical. Radio has such great possibilities for communication to regions that really are devoid of outside or even internal events, for starters. It is destressing to see the lengths having to be gone to so that can remain.

73's Dave
Tony AA7FR

 

Tony, you're sure right about the implications of moving away from traditional tv or radio and the impact on rural areas. . . I have relatives in rural So. Ohio and a TV antenna is a must on every roof there. It's not going to be easy to pull that one off.

Dave

 

Oh my goodness, no. Cell companies re-farm their spectrum all the time. 800 MHz is very much in use.

 

Hmm. I did not know that. Where I live in the Rockies, it is absolutely dead, I have scanned the entire 800 mc band multiple times. It must differ from region to region. Thanks for that information.

Tony
AA7FR

 

Here's what it looks like in Silicon Valley. Two 10 MHz LTE channels (one at 874 MHZ and one at 885 MHz) using pretty much the entire downlink band (869 to 894 MHz).

 

This is a great article, Dave. I hope many more read it. And yes, the mindless antics on 7.200 MHz threaten amateur radio spectrum security. All the morons who frequently operate there, simply playing with their radios and displaying their ignorance, reveal their true selves to the great disgust of many; they need an FCC special spectrum reassignment...to 27 MHz CB!

73,
W4AEE

 

Thanks Mike. I agree with you that antics like that don't show well for our interests. Glad to have your compliment, as well. Dave, W7DGJ

 

Nice Article Dave!
A couple of personal observations...

The lack of use of 2m...
There are multiple reasons at least in my area:
* Adoption of Digital voice modes on established Analog Repeaters which alienated Long standing Analog Users/ Club Members. IMO this resulted in a less than friendly repeater community as a whole as Hams fought for the same resource.
* Allowing over building of Repeaters by Individuals instead of Clubs. In my area there are 22 Repeaters within 25 miles on 144/220/440.
* The proliferation of FT8 across all VHF and above frequencies had pulled users from traditional modes as it has on all Bands.

Regarding Self Policing...
This has always been the cornerstone of the Amateur Radio Service. Before the ARRL eliminated the OO (Official Observer) program, we had volunteers which would monitor frequencies, and send out citations on behalf of the Amateur Radio Community. If you got a Pink Slip in the mail, you knew you messed up and were only a few steps away from the FCC showing up at your door. The ARRL simply replaced one program with another.

Technician License...
We seem to give the impression that the Technician License is a "Beginner" license.
In reality the new NC Tech has more privileges than the Technician license it replaced.
But unlike the old Novice License there is a lack of new or reasonably priced used All Mode VHF/UHF equipment, so they don't see much more than 2m FM and get turned off.
Additionally I'm not sure that allowing applicants to sit for more than one level at a time and awarding them the highest of the tests they take helps us as a whole. This allows people to "skip" the Technician license without the experience they gain in having a "Beginner" license.

 

6m yeah, ft8 destroyed CW and SSB. There's no regular ft8 on 2m VHF or higher, on 2m during VHF contests only.

 

Thanks Ron, good comments. There's a certain "maturity" gained during the time you spend on a Technician license, or in my case, the Novice license. You need that in order to understand real-world aspects of your station and of the culture of "doing radio." I have a friend who sat for the Tech Class license, got it and that night went on to General and then Extra Class. The next day that ham could get on the air and do anything, but had no real radio experience under the belt. As you say, it may not have been fair and perhaps even hurt them in the long run. Amazingly smart person though . . . three license classes in one night! That friend is rarely on the air now and I wonder if that would be the case if they'd gone through the cycle the same way most of us do. VY 73, Dave

 

It's lazy man ham radio. Oh look at me, I'm making DX contacts and working toward my DXCC while eating Cheetos and drinking beer.