Wednesday, September 14, 2016

Nexus 6 Review: Wi-Fi Done Right

I've been a Droid user for many years.  Started out with the Droid 1 then onto a Droid 2, Droid RAZR Maxx, Droid Ultra, a very short-lived and painful experience with the Droid Turbo, then a Droid Maxx which is essentially a slightly fatter Ultra with more battery.  When my battery's capacity started to run short, I started looking at other phones.  I decided to get a Nexus 6 (unlocked from Amazon) when Google announced that they would roll out Wi-Fi Assistant to all Nexus phones.

Wi-Fi Assistant was originally a Google Fi feature that applies a VPN to open Wi-Fi access points - without user intervention.  In fact, Wi-Fi Assistant is now (once you have the Play Services 9.6 update) capable of securing all open Wi-Fi, even ones where you manually connect.  This is a huge move by Google that will hit the cellular carriers hard because if I'm able to use public Wi-Fi with confidence, and my phone is latching on to open Wi-Fi by itself - why do I need a large data plan?

This all takes Wi-Fi a step closer to being a viable alternative to cellular data, although there are still many issues.  The problem is that managing a Closed SSID network is painful and complex, and Open SSID networks are subject to abuse.  Wi-Fi also suffers from a handoff problem (i.e. it has no handoff method) and it's fairly easy to do a man-in-the-middle attack in coffeeshops - without 802.1X there's no way to know if that "xfinitywifi" hotspot is really Comcast or not.  Wi-Fi Assistant solves that problem by providing a VPN back to Google's servers.

zOMG so fast!
So far I'm very happy with the Nexus 6.  It's a two year old design but it feels quite snappy.  Google's clearly still putting effort into development, and the Android is pure - no Verizon or Motorola/Lenovo weirdness.  It's a bit larger than I'm used to, so I'm glad I didn't get the Nexus 6P, but I have large hands so it works for me.  Wi-Fi in the 5 GHz band using 802.11ac on the Nexus 6 is fast.  It easily maxed out my 75 Mbps DSL connection in a speed test.

For a while I'd been using an iPad in the evening because the screen was much better than my Droid Maxx.  Now the iPad sits forgotten for days at a time, as I find the Nexus 6 screen good enough to handle almost anything.

Sunday, September 4, 2016

K6BJ - 100 Years of amateur radio in Santa Cruz

The K6BJ amateur radio group is celebrating it's centennial on September 17th, and the Santa Cruz Museum of Art & History.  Information can be found at www.k6bj.org - come to the coast and celebrate a century of amateur radio tradition in Santa Cruz County!

  • September 17, 11:00am - 3:30pm
  • FREE Admission

Santa Cruz Museum of Art and History
705 Front Street
Santa Cruz, CA 95060

Thursday, August 25, 2016

Workbench: Screw Terminal Adapters and Lever-Nuts

Having collection of connectors with screw terminals or lever clamps is very useful.  In a pinch you could do a field-repair on a headset, a rig interface, or resurrect a broken power cord with just a pocket knife and a screwdriver.  Here are some of my favorites:

DC Barrel Connectors - these can be used to make a quick disconnect (in lieu of a switch) or an extension cord.  If you just want the plug to match an existing device, you'll have to measure the outer diameter and inner pin.  Most of the time the outer dimension is 5.5mm, and the inner pin is either 1.7mm, 2.1mm, or 2.5mm.

2.1 x 5.5mm paired DC Barrel Connectors
http://amzn.to/2bEavs4

TRS "Phono" Connectors - these are really useful for building test cables or attaching a rig interface to the ADC port on an Arduino or ESP8266.  When you get to the mountain for a SOTA activation and realize your 5 year-old has yanked the end off your headphones, you'll want one of these.

1/8" (3.5mm) Tip-Ring-Sleeve "phono male" plug
http://amzn.to/2bjqfOS

1/8" (3.5mm) Tip-Ring-Sleeve "phono female" jack
http://amzn.to/2bj6JVy


For pocket tools, I prefer the Leatherman ES4 Squirt.  (http://amzn.to/2bEe5lV) It's a ham's dream tool, with a wire stripping jaw, knife, scissors, file, and a screwdriver bit that works well on these screw terminal adapters.












Other interesting stuff....

Wago Lever-Nuts - these are really useful for quick repairs or experiments where you want to easily connect and disconnect wires.  You can use them to quickly add sections of wire for tuning dipole antennas.  Lift the lever, slide in a wire (or wires plural) and drop the lever - done.  Made a mistake?  Lift the lever, change, drop the lever.  They'll handle up to 400 VAC and 20 amps, so they can be used for household electrical repairs or rig power cords.  I keep a handful of these in my field bag, some my glove compartment, and a bunch on my bench.  I prefer the newer 221 Series because the lever is wider and easier to manipulate.
http://amzn.to/2bEcNY3

BNC Female w/ screw terminal - these are 75 ohm, designed for CCTV installs, but for receiver testing or low-power transmit they'll work OK.  Be aware that some adapters like this actually have baluns, which you don't want for RF testing.
http://amzn.to/2bE9Yq1

RJ45 screw terminal plug - kinda bulky, but it's great for designing cables on a bench.  When I'm done and have a working design, I build a real cable using CAT6 and an RJ45 crimper or a punch-down terminal block.
http://amzn.to/2bJ6pxr



Sunday, August 21, 2016

Repost: How to fix a Toyota Brake Light

Note: This is a repost/update from my old blog. 

Toyota Highlanders are well made cars - I bought a 2004 for my wife who later upgraded to a Sienna minivan, so I took the Highlander for myself.  It's at 130,000 miles and still going strong.  However, apparently they have a known problem where the brake lights on one side will intermittently stop working.  I've had people pull up next to me at stop lights and tell me I have a light out, then I get home to find the light is fine.

Then recently the light went out and stayed out.  I replaced the bulbs but they remained out.  Fuses were fine, my trusty Fluke 77 said voltage was getting to the assembly.  Posters in Toyota forums said that dealers are asking $40 - $140 for diagnostic, plus possibly $300 to replace a "circuit board"...?  Sounds like a scam to me.

I did some searching online and found reference to how the contacts on the bulb holder will get compressed and not make proper contact. (Kudos to Berto for the original post and Kujath for the photos.)  Kujath suggested using a flat-blade screwdriver to bend the contacts a bit, but I think a needle-nose pliers works better since you can control the amount of bending.  I did both bulb holders and the lights are working just fine. 

Monday, August 15, 2016

Use It or Lose It : Google makes a play for part of the 3.3 GHz amateur band

I've presented several times at Pacificon on the topic of spectrum auctions and the threat to amateur radio's allocations.  In my talk Ham Radio Must Die (So It Can Live) at Pacificon 2010, I specifically talked about the threat to the 3300 - 3500 MHz band.  The threat increased exponentially when the FCC converted the 3500 MHz band to the Citizen's Broadband Radio Service for use in heterogenous networks and densified mobile data systems, and now Google is asking the FCC for permission to test a wireless last-yard technology for delivering Google Fiber service in the upper half of the 3300 MHz band.

In my Pacificon talk I pointed out that the 3300 MHz band is almost never used, and the possible auction valuation to commercial users is very high.  If we presume a $2 per MHz-POP auction price (which is about what the AWS-3 commercial carrier spectrum went for) and a US population of 320 million, the value of the 3300 MHz band is $128 billion.  The AWS-3 auction, record-setting though it was, only raised $47 billion.  For a government $19 trillion in debt, $128 billion isn't much but it's a start.  Google could afford to buy that spectrum, and with the unprecedented access it enjoys due to the revolving door between itself and the White House, it has the political clout to make this happen.

There are just over 800,000 licensed amateur operators in the USA.  $128 billion puts the value of our 3300 MHz band at $160,000 PER OPERATOR.  For something we never use.  I'd be willing to say (and I'm being very charitable in this estimation) that 0.1% of all US operators make use of the 3300 MHz band.  That's $160 MILLION PER ACTIVE OPERATOR.

I'm not saying what Google's doing is right.  If you think it's wrong, file comments with the FCC.  I'm saying what they're doing is not surprising, and that I predicted this would happen six years ago.