Category: Elmer’s Sage Advice

WebSDR: Listen to Repeaters in Salt Lake City, and Make Other Fun Radio Links

On: By: K7DAA

The Northern Utah WebSDR receiver system has a unique feature that allows you to listen in on local repeater activity in the Wasatch Front area of Utah. Like the other WebSDR receivers, it allows you to listen to activity on the 1.8 to 30 MHz HF bands, but they’ve added another remote receiver for local VHF/UHF activity. This receiver is located southeast of downtown Salt Lake City, on the face of the mountains, about 600 feet above the valley floor. For those of you familiar with the area, it is near the entrance to Parley’s Canyon, where I-80 and I-215 meet. To get from the SLC Airport to Park City, you go right past this area.

Someone has taken the time to mark all of the repeaters that can be heard on the tuning ruler, so all you have to do is click on one of the little brown flags to move from one repeater to another.

NOTE: Before you go any further, if you use the Chrome browser, or any based on Chrome, make sure you remember to click the colored box above and to the right of the tuning dial that says CHROME AUDIO START or you won’t hear anything on any of the WebSDR receivers. Also, please know that if you click these links from an Android or iOS device, you may get re-directed to a different receiver page that might not have the same capabilities. Nothing wrong with your stuff, just a limitation of the design of these awesome receivers. In fact, I sometimes listen to 75 or 40 meter nets with my iPhone, so it works, just a bit differently.

Here are a few web links you can copy/paste (or just bookmark this page) that you can save into your web browser:

This is the 146.62 repeater, the busiest in SLC, and links to one in Park City

Here is the 146.76 repeater, also quite busy, and is my “home” repeater, covering Salt Lake, Davis and Utah (where I am) counties area.

147.12 repeater near our TV towers on Farnsworth Peak (named after Philo Farnsworth, the actual inventor of television), southwest of SLC. This repeater is part of a wide area network of RF-linked repeaters up and down Utah. It is called the Intermountain Intertie system, rivaling the famous Cactus Net for sheer coverage. It also covers southern Idaho (Boise, Idaho Falls), parts of Wyoming, Montana, Yellowstone Park, Flagstaff and Phoenix, AZ, and Las Vegas. Lots of activity here as well. Unlike Cactus, all may use it without fees or membership. Read more about it here

By the way, many of the WebSDR receivers allow you to make your own weblink that you can save or bookmark. It allows you to instantly go to a particular WebSDR receiver, frequency and mode. You can see how I did this by examining the URL’s in the links above. Or, for example, if you like listening to the NoonTime Net on 40 meters from about 10 AM to 2 PM every day, your link would look like this one below. Go ahead and click on these examples if you’d like. I made sure they work:

http://websdr1.sdrutah.org:8901/index1a.html?tune=7284lsb

Note the data after the question mark. Just replace the frequency in kHz with whatever you want, and then add the mode, such as cw, usb, lsb, fm, or am. That’s all there is to it. If you want to listen using a different WebSDR receiver, just use its URL, and add the same frequency and mode data at the end. Here are two more examples of the NoonTime net again, but listening first from the KFS receiver near Pacifica, and right below it is the same net, listening from Phoenix.

http://69.27.184.62:8901/?tune=7284lsb

http://w7rna.com/?tune=7284lsb

Easy, right? Here’s another hint if you’d like to monitor several frequencies or repeaters at once. All you need to do is start one receiver session by clicking one of the above, then open a new browser instance or tab, then either click another link or paste one in, then go. Note that sometimes opening just a tab doesn’t give you audio from both receiver instances at the same time, depending on your browser. It worked OK for my Chrome browser, but your mileage may vary, etc.

OK, here is one last bonus link. If you would like to practice listening to CW, here is a link to 7047.5 kHz. It is the ARRL’s station W1AW. Every day it sends plain text from a recent issue of QST magazine at varying speeds. Very good practice, but don’t freak out if you happen to arrive while it’s sending at 35+ WPM! Yeah, I can’t copy most of that either. If you look at the web link, note that I inserted the frequency as 7046.75 kHz to get to 7047.5. I don’t know why, but on CW, it’s 750 Hz higher. Maybe a quirk. I dunno. I’ll come back and edit this if I figure out why.

There you go–you’ve got lots of cool receiver power all over the planet for the price of…nothing. Can’t beat that!

What Are Those Weird Tones?

On: By: K7DAA

Contestia Signal

If you tune around the HF bands, you’ve very likely heard strange-sounding tones, squawks or beeps, and wondered what they are. Here is a link to a very well-done Wiki that gives you audio samples you can listen to, and a brief explanation of all sorts of different modulation types found on the Amateur bands to help you identify what you’re hearing:

https://www.sigidwiki.com/wiki/Category:Amateur_Radio


Apollo 11: How NASA Got All That RF From The Moon Back To Earth

space research science astronaut
On: By: K7DAA

This is a very good article that we hams might enjoy reading! It’s about the first moon landing in 1969, and how video, voice, and astronauts’ heartbeats were all sent back to Earth using frequencies and modes we are familiar with today. It was all analog stuff back then, and communications were sent “in the clear” without encryption. Of course, that meant some hams got to listen in!

Read all about it here:

https://www.rfcafe.com/references/electronics-world/communications-moon-electronics-world-august-1969.htm

Note that the “S” band microwave frequencies mentioned in the article are just a hair outside of our present 13 centimeter ham band that covers 2300 to 2450 MHz. A chunk of our 13 cm band (2310-2390 MHz) got taken away a few years back, and is now used by, among others, Sirius/XM satellite radio. If you’re one of their subscribers, it might be fun to know that the music coming out of the speakers in your car is from a satellite transmitting inside of an Amateur Radio band. Think about that while you’re driving around, listening to the Beatles Channel (Ch.18)! Oh, and of course, we also share almost half of the 2.4 GHz Wi-Fi and Bluetooth band with the world. Ask me sometime how we got there…

A Few Items from Tonight’s Tech Net

On: By: K7DAA

On tonight’s tech net, the main items of discussion centered around coax, antennas, power supplies and batteries.  All things that we as hams have to deal with.  Due to the length of my explanations here, I’m going to skip batteries for now, and just throw down a few thousand words about coax and antennas:

Coax

Coaxial cables come in many different types and sizes.  One question was why are there so many different sizes of coax?  Without getting deeply into the mud, I suggest that there are broadly two main reasons:  loss and power handling capabilities.  Let’s talk about power first, since it’s pretty straightforward.  The more power a coaxial cable needs to handle, the bigger it must be.  Part of that is like battery cables, the center and outer shield have to be beefy enough to handle the power.  Another part is that the more power going through a coax cable, the higher the voltage difference is between the center conductor and the shield.  Just like with high-voltage transmission lines, as the voltages get up into the thousands, the two parts of the coax must be moved further and further apart to keep them from arcing over.  I have seen coax in use at a 50,000 watt TV station that is larger in diameter than my arm (and I’ve been working out!).

Regarding loss, the general rule is that the smaller the diameter of the coax, the greater the loss is going to be.  Also the higher the frequency we’re using, the greater the loss is going to be. In the Wi-Fi consumer electronis industry, we routinely use 50 ohm coax cable smaller than the lead in a pencil because of the need to be able to snake the cable in and around very tight spots.  We accept the fact that the loss of this cable in the 2.4 and 5.0 Gigahertz WiFi bands is substantial but, due to the short lengths we usually use, it’s acceptable.

Below is a quick list of coax cables you are likely to meet as a ham.  There are hundreds of types, so this is a very pared-down, ham-friendly list.  RG-174 is often used by QRP (low power) operators, because it is small and light, and easily carried in a back pack or go kit.  RG-214 and RG-8 are a bit over 1/2 inch in diameter, and like LMR-400, are your best bet for carrying VHF and UHF signals for 50+ feet without too much loss.  In fact, please use LMR-400 rather than either RG-8 or RG-214 for VHF+.  RG-214 has a double shield, and is quite expensive, but good for use in repeater cabinets.  RG-8 and its cousins are good for 2-30 MHz use, and is much cheaper also.  Note that these thick cables can also withstand 5,000 volts, and RG-6 (75 ohm cable TV) is only good for 350 volts.

So why did we settle on 50 ohms for most coax?  Actually, 72 ohms is best for least receiving loss of very small signals, and that’s why the cable TV industry like it.  It turns out that 50 ohms was calculated back in the 1930’s (and re-calculated many times) to show that it was the best impedance for transferring power.  For receiving, 72 ohms is still best (and some hams use 72-75 ohms for that reason), but 50 is a good compromise.  It also turns out to be a happy value, close to the natural impedances of certain types of monopole and dipole antennas.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Antennas

Taking the simple example of a steel wire antenna poking up from the center of a car’s roof, if it’s about 19 inches long, we can say that this is a quarter-wave antenna in the 2 meter ham band.  It radiates (and also picks up when receiving) signals from directions generally best represented by imagining throwing a big, inflatable doughnut over it, like the ring-toss game.  The pattern favors the horizon in all directions out from the car, with some pickup also from maybe 30 degrees above and below the horizon, as this drawing shows:

This 1/4-wave antenna has a slight gain (meaning you get more power or received signal than you put into it!) compared to an isotropic antenna.  Isotropic is a theoretical pattern described by a beach ball–it both transmits and receives well in all directions.  Our 1/4 antenna gets about 1.2 dB (abbreviation for decibels, which relate in logarithms of the powers of 10, so 3 dB is a doubling or halving of power) more gain at the horizons only compared to an isotropic antenna, because we squished that beach ball with giant hands down in the middles, top and bottom.  It’s all the same amount of energy that we started with, but we’ve squirted a larger amount of it in a direction that’s more useful to us!

Speaking of squishing a beach ball, now let’s squish it down in the middle even more by changing the antenna to a 1/2-wave type.  A half-wave antenna simply squirts even more energy at the horizons (so the signal goes further across a city, for instance), and even less up or down.  We also lose more of that fat, doughnut shape, and it starts to look a bit more like a frisbee, but (and here’s the big deal) more of it squirts out towards the horizons, which are the useful directions we really want our signal to go.  Here is an image showing “Unity”, or about like a 1/4-wave antenna, then two more antennas that have 3 and 5 decibels of gain over a dipole (that’s the little “d” after the “dB”, it’s the thing we are referencing ourselves to).

 

That’s all antenna gain is–we refocus the energy from that theoretical beach ball in directions we care the most about.  A beam antenna becomes more like the reflector on a flashlight.  Held in the open, a flashlight bulb somewhat weakly puts light out in all directions.  However, that same bulb, now placed in a flashlight with the reflector right behind it, can really put out a strong beam, but only in one direction.  Dish antennas are very close to flashlight reflectors, and accomplish pretty much the same task: they reflect back any energy in a single (well, mostly) direction, causing increased signal in that direction.

So, broadly speaking, gain-type antennas create this wonderful gain because they redirect the antenna’s energy in the directions we care most about.  Make sure you walk away from this little tutorial with one important thing in your head:  Gain antennas don’t create any new energy.  If they did, the Law of Conservation of Energy would be violated, and would probably get quite upset about being violated in such a rude way.  No new energy, simply the same amount aimed where we would like it to be most effective.  The universe maintains its balance.  No dark matter was harmed in the making of this movie.

Aha, so “gain” is actually a misnomer, isn’t it?  There is nothing gained in one place that isn’t also equally lost in some other,  thus maintaining nature’s balance.  Maybe instead of calling them “gain” antennas, we should start a campaign to call them “redirecting” antennas.  Well, maybe it would catch on…

As a final thought, we can make gain antennas either by making them a certain length, or by stacking multiple antennas, or by brute-force reflectors (like a dish).  It turns out that certain lengths of antennas have more gain than others.  A half-wave has 1.2 dB more gain than a 1/4-wave.  A 5/8-wave wire has 3 dB more gain than a 1/4-wave wire.  Stacking several 1/2-wave antennas has more gain than them all!  The only “trick” to getting all this gain is that you have to make each new length or added antenna happy by matching it to the exact impedance of the rest of the antenna system, and that can get tricky, because it will rarely be 50 ohms. Not super-difficult, just tricky.  The reason everyone likes a 1/4-wave antenna is because,given a decent ground plane to work with (the car’s roof, in this case), it happens to come out to a nice, round 50 ohms characteristic impedance.  That means we can connect any old 50 ohm coax, and we’re done!

What if we want the gain and directionality of the 1/2-wave antenna?  OK, here’s a new challenge:  The 1/2-wave antenna, at its two ends, are thousands of ohms in impedance, instead of just 50 ohms (but you can find 50 ohms in the middle of that 1/2 wave antenna–makes sense?).  Darn, now what?  Well, we have to create a (hopefully simple and small) matching network to transform 50 ohms to several thousand, and connect it up to our half-wave antenna.  The trick (and the reason I get paid for this!) is to lose as little energy as possible, and make it for cheap and simple.  I can tell you that the matching network will probably involve an inductor (small coil of wire) that has a tap on it about 1/4-1/2 turn up from the bottom), and a capacitor to resonate with the coil near the design frequency.  Depending on how big and lossy those parts are, we could easily lose most of the gain.  You won the battle, but lost the war, so to speak.  (RF engineers’ joke:  What do you get if you end up with a poorly-designed matching network?  Answer:  New antenna company on eBay with offshore mailing address!)

OK, haha, thanks.  So adding a bunch of 1/2-wave, 5/8-wave, or even 3/4-wave antennas together will give you more and more gain, offset by whatever losses you have in your matching networks (and there’s always some energy lost).  A vertical stack of these antennas to make one high-gain, 20 foot-tall antenna of maybe 9-12 dB is called a collinear array.  All the while, that pattern you see above gets flattened more and more out towards the horizon.  Is there a practical limit to the size of a collinear antenna?  Yep, eventually, the losses in your matching networks at each junction of new antenna elements will add up to give you diminishing returns.  You will have less and less of the original energy available down at the antenna connector.  The array also becomes more and more mechanically unstable until finally someone shouts “Jenga!”  Again, you’re welcome.

Items covered in our 1/4/17 Tech Net

On: By: K7DAA

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.

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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.

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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!

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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

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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 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.

Thoughts and Links to a Few Things Discussed on Our Tech Net Tonight

On: By: K7DAA

PL on your receiver, or CTCSS:

We all know that you need to transmit a PL tone to unlock a repeater.  That’s how we keep repeaters from keying up unnecessarily.  In the old days, when there weren’t many around, we didn’t use PL at all.  Today, with ham repeater channel pairs all used up in all metro areas, it becomes necessary to place repeaters on the same frequency, and as far apart as geographically as possible, but then separate them further by requiring each to use a different PL tone for access.  That way we get better frequency reuse, where we can place them somewhat closer together, and users can make sure they only bring up their own system, and not the other ham group’s repeater.

On our own receivers, though, there has never been such a rule that we use PL.  The official term for PL on your receiver is CTCSS, which stands for Continuous Tone Coded Squelch System.  It basically means that, when set to this mode, you won’t hear anything from your receiver’s speaker until it hears a specific subaudible PL tone to open it up.

By the way, you would be correct to say that, while your own radio might not need to use it, when seen from the perspective of the repeater, it indeed uses CTCSS on its own receiver before your voice gets repeated.

OK, so besides not hearing other people on your repeater’s channel that might be far away, what other use does CTCSS have.  There are a number of them, but I’m only going to mention one other that you may care about.  If you are walking or driving around, and hearing occasional beeps, squawks, or blasts of white noise from your radio, using CTCSS will prevent random junk from coming out of your speaker.

As an example, in my house, my cable modem emits a digital harmonic that just happens to fall right on 147.33 MHz, the frequency of our two meter repeater.  I can’t monitor that frequency for very long without CTCSS, because the receiver is always opened by the digital noise.  With CTCSS, it’s blissfully quiet until someone keys up the repeater, which transmits a PL tone to my receiver, opening up the speaker.

As a parting note, beware that there are still quite a few ham repeaters that don’t transmit PL.  You’ll just have to check on a case-by-case basis.  To save you a little bit of time, I can assure you that all of the K7DAA, GVARC, and SBCARA repeaters do transmit PL.  On the two K7DAA repeaters, I also perform one other, very minor trick:  I turn off the PL transmit tone about 1-2 seconds before the repeater transmitter drops.  This gives your receiver time to notice that the PL tone is gone, and it again mutes the speaker before the usual squelch crash when the repeater’s transmitter drops off the air.  Nothing is perfect, though.  You’ll still hear a crash after an ID or other very short transmissions, but not during regular conversations.

 

DMR (Digital Mobile Radio):

I’ve bought two of the TYT MD-380 UHF DMR radios for $100 or so on Amazon (a click opens an Amazon search window–multiple vendors)

Hytera is a well-respected name in the DMR two-way radio industry.  They are now marketing to hams through

Hotspots:  Even though most of us in the South County and Hollister areas can use the W6YYY DMR repeater on Crystal Peak, it’s very nice to have your own little DMR system at home or portable in the car.  At present, the two most popular ways to do this are:

  1.  Buy the SharkRF Openspot, a relatively new all-in-one product with no DIY skills needed:  SharkRF website here
  2.  Buy the DVMega board, plug it into either a Raspberry Pi, an Arduino, or a board (if you use Android), and add software

By the time you are done, any of the above will end up costing you about $200-300, just so you know.  The Shark has the least number of fiddly things you’ll have to do to get it running, but the ham that sells them gets backed up often, so you’ll spend a week or three in back-order status (not a big deal, though).

The BlueDV is a neat unit that you can control with your Android device, but as an Apple guy, I didn’t find that as attractive.

If you do Arduino, make sure you buy the Arduino Due (Due is Italian for Two).  Not just any Arduino will work.

If you go the route I did, with the Raspberry Pi, be sure and get the Pi 3 like I did.  It is faster than the others, and has built-in WiFi.  All of the choices in #2 use the DVMega radio board.  Note that you can buy either a single- or dual-band board.  There is about $40 difference.  I bought the cheaper UHF-only model, since almost all of the DMR activity is on UHF around here.  I also mentioned the DHAP, which is the 3D-printed case that my hotspot rides around in.  It’s perfectly OK to put a DVMega/Pi combo in one of the taller cases designed for the Rasberry Pi (and only $12 or so), but I wanted something more integrated that also included space for batteries.  That’s how I ended up with the Hardened Power Systems DHAP case.  It’s $99, but includes a dual-mode power supply, and space for four 3.7 volt Li-Ion batteries for easy portable use.  I had to wait about 3 weeks for delivery, by the way.  And yes, I got the bright yellow one!

So far, I’m the only one in the area with a DMR Hotspot, but Dan, KJ6LXX says he might go for a Shark, so feel free to ask him for opinions.  If you try to duplicate what I did, I can certainly help you with it.  Since we’re in the very early days of DMR radio, not a huge amount of “…For Dummies” guides are available yet, so don’t feel shy about asking lots of questions, or for help getting something going.

Mel, KK6MES, and Steve, W6MNL, are the two folks whose brains I’ve been able to pick regarding the DMR world, so feel free to hit them up with questions if/when you hear them on the repeater.

As was also mentioned tonight, the listing of DMR radio manufacturers roughly by cost and features as of today:

  1. Motorola–top of the line, expensive, but used gear on eBay.  Watch out for $300+ programming software you must have!
  2. Hytera–like Motorola, the only two that can do roaming across multiple ham repeaters.  Just began marketing to hams.  See Gigaparts above.
  3. Connect Systems, or CSI–very ham-friendly people, very solid gear, American company.
  4. Kenwood–surprise!  Let’s see what Kenwood brings to the market in DMR.  Note the link to VA3XPR.net, a good source of DMR news
  5. TYT or Tytera–I know, they’re Chinese, but several of us really like their MD-380 radio.  UHF-only, excellent tx and rx audio, easy to use.
  6. All the other Chinese vendors, only because I don’t know their product personally.  Wouxon and Alinco also have ham DMR stuff.

As a parting thought, before I buy or build any of the above, I usually have a look at various reviews and comments on all these items on YouTube.