Where are the Hams? AT&T's Latest endeavor into Broadband Over Powerline (BPL) called "AirGig"

On September 20th, 2016 I read an article on Yahoo's fiance pages about AT&T's latest foray into transmitting high-speed data over conventional electric transmission lines. The Yahoo article goes on to say that AT&T has "developed a new technology it calls AirGig, which links up to standard power lines and uses a special transmitter to deliver super-fast gigabit internet wirelessly." As many of you probably know this is not AT&T's first attempt to bring BPL to the masses. The ARRL published a news article on it's website on September 21st, 2016 which reminds us of the previous efforts to establish BPL and the previous ARRL opposition to that technology.

This time the ARRL seems to be taking a less hostile approach to the technology ,claiming that the new millimeter wave based technology, operating in the 30 to 300 GHZ range should cause little interference to Amateur Radio. The ARRL article states "that it is not likely that the AT&T technology will even use Amateur Radio bands, so there is little reason for concern even among those amateurs who use spectrum above 24 GHz."

I'm sure that there will be lots of discussions about the pros and cons of BPL reignited by this newest incarnation of BPL but what struck me as I was reading the articles was where were the hams in the development of this technology?

If this is an RF technology, shouldn't we be the champions of it while we protect our interests at the same time? Or is the reality such that we are we no longer at the forefront of technology? If this is true, why and who can we blame? 

Lastly, shouldn't we be concerned about all potential sources of pollution to the radio spectrum and not dismiss those sources simply because they are outside of our bands? I can't think of a better way to demonstrate our professionalism and service oriented nature then by preserving our threatened natural resource.

I'd like to hear the opinions about this. Please feel free to comment.

73,
Ed N3EML

The Yahoo article can be found here, http://finance.yahoo.com/news/t-invented-way-power-lines-202213172.html?.tsrc=daily_mail

The ARRL article can be found here, http://www.arrl.org/news/at-t-s-new-airgig-not-your-father-s-bpl

The Mother of All Clock Radios!!!!

Back on August 6th, I went to the Niagara Frontier Wireless Association's Antique Radio Swap Meet. It wasn't a huge turn out but it was still a nice way to spend a Saturday morning. There were a lot of really cool vintage radios, TVs, and parts to look at. There were also a lot of Antique Radio Aficionados on hand to make learning an important component of the Swap Meet.

As I was wandering around looking at the various radios on display and for sale, I noticed this towering pinnacle of ingenuity...

Here is the clock face...

Here is the radio...

Kind of the best of two worlds! A Clock and a Radio... Genius!
I did a bit of quick research and I think this is a Philco 570 from circa 1931. More information on the Philco 570 can be found over on TubeRadioLand.com, The Philco 570 was supposedly introduced in November 1931 and sold for a whopping $89.50 USD. Wow! That was a big chunk of change back in 1931.

Check out this really great book about Philco Radios that is available from Amazon...

Supplied SDR (DVB-T) Antenna Operating Near 15 GHz!!!

I bought a couple of SDR (DVB-T) dongles recently. In general the antennas that come with these are basically cheap junk across the board with few exceptions.



I always carry the SDR dongle with a homebrew HF Upconverter, Long Wire Antenna, and the UHF vertical antenna that was supplied with the dongle in my backpack. Last weekend I was tinkering around with the SDR at home and hooked up the supplied UHF antenna. (BTW... I almost never have used this antenna because normally I have used the SDR for listening to HF). Much to my dismay, I could just barely hear a signal that I was generating locally with my GPS Controlled Frequency Generator.

Strange.... So, I started looking into the problem, tried a different antenna and found that all was well. O.k. so now I knew the problem was at least localized to the Supplied UHF antenna, attached coax cable or connector. Here is a photo of the base of the antenna...

I carefully removed the protective plastic from the base of the antenna (basically just a sticker applied to the base), then carefully pried out the small metal insert that has the magnet attached. Here is what I found...

A 15Ghz Quarter Wave Antenna! (i.e. about a half-centimeter of un-terminated coax end).

Talking about a cold solder joint. Man! it was horrible! Anyway, I fired up the trusty BlackJack BK6000 Solder Station (I highly recommend the BK8000) and quickly had the coax center conductor re-soldered to the antenna connection.

TaDa! Bob's your Uncle! The antenna is still a cheap piece of junk but signals are now received.

Click on the image below to learn more and purchase the BlackJack BK8000 Soldering Station with Hot Air Gun, Solder Pencil, and Solder Removal / Extractor Gun.

SDR Dongle is Deaf! But wait there is more.....

Sometime ago I built an HF Upconverter to use with my NooElec SDR Dongle. I ran into an interesting scenario. The mixing device is an SA612, the LO signal is provided by an Si5351 Breakout board from Adafruit instead of the traditional 125 Mhz oscillator.

Notice the spectral display with the power brick connected to my Laptop...

...and now without the power brick connected to my Laptop...

Can you see the difference?

The power brick raises the overall noise floor by about 10db across much of the HF spectrum! The overall effect of this was to make the SDR receiver seem pretty deaf to desired signals.

This is a common problem with trying to use switching power supplies in the ham shack. I was able to clean this noise up quite a bit by adding two additional clip-on ferrite rings to the output cable of the power brick. The cable already had one ferrite ring installed by the power supply manufacturer.