Items covered in our 1/4/17 Tech Net

In this week’s first-of-the-month Tech Net, we covered quite a wide range of Q’s and A’s, as well as some new and old laws on the books.

The first of those laws is the new California restriction on distracted driving and cell phone use that does not exempt holding an amateur radio mike or walkie talkie in your hand.  Nobody knows yet how this is going to play out, or if any hams are going to end up being pulled over.  Here is the paragraph taken from State Assembly Bill AB-1785 that defines what a “restricted device” is:

(f) For the purposes of this section, “electronic wireless communications device” includes, but is not limited to, a broadband personal communication device, a specialized mobile radio device, a handheld device or laptop computer with mobile data access, a pager, or a two-way messaging device.

I guess we would be caught under the “specialized mobile radio device”, but the wording, and even the definitions they provided, are so vague that I could probably be pulled over for talking into a corn dog.  And yes, they did exempt anyone operating as an emergency services person.

++++++++

Along this the above new law is a requirement that the restricted device be mounted to the dashboard.  One of our members reminded us of another law that is in effect that does not allow you to mount anything in the center of the dash, or on the low-center part of the windshield.  You must mount your GPS, phone, or whatever in either the right or left corner of the dash only.  The idea being that anything mounted in the center will obstruct your vision.

++++++++

Sugru is a neat, new product that just might find a use around your home or garage.  See it here:  http://www.sugru.com  It is a flexible, heat- and cold-resistant, grippy and moldable polymer that can do some pretty cool things.  After you mold it to the shape that you want, it remains flexible.  Easiest thing to do is to have a look on their website at the pictures and also videos that show some good ideas.  Aaron, W6TDR, brought it up and mentioned that he’s used it.  I have several sample kits of it, but I haven’t actually used it yet.  I also got a fun kit from them that includes some button magnets.  Oh boy!

++++++++

We talked briefly about using silicone grease (not silicon!) in RF connectors to displace water and to keep corrosion off of connector pins.  I am also reminded that I used a small tube of silicone grease on several rubber o-rings that I recently installed inside of my new water softener.  Avoid using silicone grease in very high-power RF, since you’ll get carbon tracking and flash-over, but for amateur power levels, that’s probably not a concern.  It is apparently OK to wipe silicone grease on the mating surfaces of RF connectors, and they will be protected from corrosion and presumably will wipe away from the points at which direct metal-to-metal contact needs to be made.  Remember that we are talking about SILICONE the polymer, not SILICON the soft metal that bursts into flames when exposed to a little moisture.  People constantly confuse the two in everyday speech.  Even those that should know better.  If you are ever having trouble remembering which is which, please refer to the “Rule of Two Valleys”:

1. SF Bay Area and Tech Capitol of the World:  Silicon Valley

2. Hollywood, full of “enhanced” actresses:  Silicone Valley

You’re welcome.

See here for further info:

https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

http://lists.contesting.com/_towertalk/1998-09/msg00477.html

Dow Corning High-Vacuum Silicone grease comes highly recommended by some 2-way radio pros.  I have my own tube of it that will probably last me a lifetime.  Here is an Amazon link to it:  http://amzn.to/2hZEHAw

+++++++++

A question was asked about whether DStar is becoming more or less popular, especially when DMR seems to be coming on strong.

My take (my opinion only, of course) is that DStar is declining in popularity, but truly DMR is experiencing explosive growth right now.  Some comparisons:

Even though DStar and DMR use the same analog-to-digital codecs, DMR’s has FEC (forward error correction) built into it, and there is much less “R2-D2” voice garbling than DStar when signal strengths get low.  In fact, because of FEC, DMR seems to get about 10-15% better range than even analog FM can do.  The only downside is that you’ll have to get your ear used to hearing band-limited, digitized audio.  This is the case for either DMR or DStar, BTW.

DStar is supported by one ham manufacturer, Icom, and has never caught on with any others.

DMR is a world-wide standard driven by the need to serve the professional 2-way radio crowd, so even though it didn’t hit the market until 2007, all sorts of radios and infrastructure are available for it now, driving down costs to $100 or so for an entry-level radio.  With DStar, I’ve always been annoyed by the “DStar tax” I would have to pay if I bought an Icom radio.

The best part of DMR for me is the wonderful volunteers that have set up several world-wide networks and charged exactly zero for the rest of us to join in.  There are tons of hams to talk to at any hour of the day.

The only downside to both DStar and DMR is that they have a bit of a learning curve as a barrier to getting started.  You can’t just buy a radio and put it on the air 10 minutes later.  That’s where a knowledgeable ham friend who has been down that road already can be invaluable in getting you started.  Now, that said, let me offer some quick steps to help you at least get to the front door of the house:

  1.  Go to http://www.dmr-marc.net/ and click on “Register ID” in the upper right-hand corner.  You will be registering for a user ID, not a repeater.  On the bottom of the next page, click “User registration” and follow the prompts where they will validate you, making sure you have an active amateur radio call.  Within a day or two, you will get an email from them with your new 7-digit DMR ID number.  You will later program this into your DMR radio.  Note that you can also go back to this website later to see what you or your friends’ DMR ID’s are, or to find the name of the person whose only info that came up was his DMR ID. Here is a direct link to the database search page:  https://www.dmr-marc.net/cgi-bin/trbo-database/
  2. Buy a DMR radio.  Most of us locally have started with the TYT MD-380, and it’s just over $100.  If you have a TYT, you’re much more likely to find help with any questions you might have.  Most of us bought them on Amazon, such as this link:  http://amzn.to/2j199am
  3. Install the MD-380 programming software on your PC (available here as a download after you sign up for their very good newsletter).
  4. Get one of us to email you a codeplug that you can program into your radio, and then you’re good to go!  We can also explain what a codeplug is, and how you can change it to suit your own needs.

Ham Radio 360 Podcast features local hams

George, KJ6VU, has a great podcast and accompanying web page with some interesting gear and DIY projects going on. They are presently doing a group build of a 1-30 MHz antenna analyzer based on the Arduino platform. Have a look and/or listen at www.hamradio360.com

 

I mentioned this on tonight’s tech net at 9 PM.  While you are perusing that website, have a look around at a few other very interesting things.  For instance, see George’s presentation from this year’s Dayton Hamvention, where he introduced the very handy portable end-fed antennas from his new company called PackTenna.

 

The presentation does a very good job of showing you how to wind some simple baluns (actually they are un-un’s) to get your 50 ohm feedline matched to the very high impedances of either a resonant, end-fed dipole, or a random-length end-fed antenna.  Or…you could buy one ready-made from PackTenna for $89.  If you go to www.packtenna.com and look around, be sure to read the QST magazine “test drive” of his antennas.  Highly recommended.

Anderson Powerpoles

powerpole05Lopping off the ends of the power connectors on your brand new gear may not sound like a good idea, but it probably is. Anderson Powerpole connectors have become the defacto standard for power connections in amateur radio. They are easy to connect, and come in a variety of amp ratings and colors. It is the power standard for ARES/RACES teams, and a quick, safe, way for hams to come together, and share power at an event or emergency. The connectors themselves are fairly inexpensive. But you will want to make a one-time investment in a proper Powerpole crimp tool. They are about $40-$50. Powerwerx has a great selection of Powerpole connectors and accessories. They also have an excellent tutorial page on how to make proper Powerpole connections. Check it out!

Switching Power Supplies

imagesWe need more power! Switching power supplies have been around for some time now. There are many options, features, and price ranges. Some have various power tap options, like CLA outlets, power poles, banana plugs, and basic screw posts. Other features may include meters, or voltage adjustment abilities. Since these are specifically marketed for amateur radios, many have RF filtering to help keep from impeding on your radio session. Some, not so much…

Continue reading “Switching Power Supplies”

Real Hams Drill Holes

radio-car1You all know “that guy” – The one with the UHF/VHF antenna (or antennas) stuck to the roof or trunk lid and wires trailing off to the side that go through a trunk, door, or window gap. The antenna maintains its death grip on the outside of the vehicle with the mysterious forces of magnetism, via a lip or edge clamp, or something that bolts to your roof rack. You wash your own car and drive a couple extra blocks to avoid parking garages. It’s all for the better you tell yourself. It is also why your significant other won’t let you touch their car.

I was “that guy”.  I also remember when I knew that it was time to no longer be “that guy”.

Continue reading “Real Hams Drill Holes”

Magnetic Microphone Mount

no_clipOne thing that seems to make amateur radio folks more squeamish than finding a bag of frogs under their bed is the subject of drilling holes in their vehicle. Drilling holes to mount radios. Drilling holes to mount antennas. Drilling holes to mount a microphone somewhere on the dash. Some of you drill holes for microphone clips, or purchase alternatives that clip onto an air vent, and some of you simply toss the microphone in a cup holder. Today, I am going to share my solution for making a magnetic microphone mount that does not require holes in your dashboard.

Continue reading “Magnetic Microphone Mount”