But, I got one anyway.

The Alinco DJ-MD5XTG. I started looking around for a more compact and slightly cheaper DMR radio as there are situations where I don't want to tote my 878's around. I stumbled across these and I was intrigued. Oh and, the software is strangely...familiar. Yep, EXACTLY the same as the AnyTone 878 as far as the interface is concerned so, I wasn't having to learn a whole new CPS.

When this arrived, I fired up my 878 CPS and exported my codeplug into a .LST format (.csv's actually) and then imported it straight into the DJ-MD5 CPS (which; is the same software basically) and BAM!

It loaded right up!

Software - wise, it's the same radio...

no bluetooth, a smaller battery (1700mah) and a few less programmable function keys. Otherwise, it appears to have the same specs for the most part as the 878's - 200,000 digital contacts, APRS TX, GPS etc.

Oh and, the Alinco as well as Ailunce & Btech are all made by AnyTone (Same Factory).

So far, I like it. I bought it for it's compact size. I haven't seen any of the bugginess reported in earlier versions of the DJ-MD5 and, it seems like a decent radio that I won't cry over if I lose it, get it wet or it gets stolen out of the truck on a job etc.

Before you move on, bookmark this site: https://core-electronics.com.au/tutorials/raspberry-pi/raspberry-pi-generations.html#Anatomy I find this site to be a great source of info regarding Pi's.

NOTE: This is a build tutorial for the basic Pi-Zero Simplex mmdvm HotSpot. There are many other build-types/variants that will not be covered here. If you'd like to do a build using a duplex board in the Pi-Zero form factor, check out Lonestar mmdvm's at: https://www.store.n5boc.com/product-page/mmdvm-duplex Of course, you will need to use a different case solution.

So, here's all the parts. The middle left is the Pi-zero computer itself. The top left is the MMDVM "Hat" which is the radio portion that sits on top of the Pi-Zero (Ya see the little antenna stub-out that the antenna screws on to?) The info screen is integrated into the hat (That black glass square).

At the bottom left and right...that is what makes up the case...think of it as the "computer case."
Oh yeah, "MMDVM" is an acronym for "Multi-Mode Digital Voice Modem".

A closer look at the MMDVM "Hat." When you buy the MMDVM Hat, it comes with the little black antenna as part of the purchase.

This is a shot of the underside of the MMDVM "Hat." Those two black "blocks" are how the Hat connects to the Pi-Zero board.

This is a close-up shot of the Pi-Zero; a little dark because I'm a crappy phone photographer - sorry. That "silver square" on the left end...that's where the Micro SD card is inserted which holds the Pi-Star Operating System that runs the show...

A side shot of the Pi-Zero so you can better see the GPIO pins that the Hat slides down onto... "GPIO" stands for "General Purpose Input/Output. Think of it as a wall receptacle in your home that you plug your Hoover vacuum into. The Pi-zero plugs into the Hat. The hat is the receptacle and the Pi-Zero has the prongs. You get what I mean...

The bottom portion of the case. We're gonna mount the Pi-Zero onto this with the two short screws...

A better side view of the case bottom and the 4 threaded mounts.

Next, we set the Pi-Zero onto the case bottom and insert the 2 short screws in at either end of the GPIO pins.

Next, we set the MMDVM Hat onto the Pi-Zero, carefully lining the "plugs" up with the GPIO pins and gently pushing it down onto the Pi-Zero until it "bottoms out." Easy-Peasey right?

The case will come with two of these pieces of Pex(?) tubing as well as four screws (two short screws and two long screws). They're just spacers that support the MMDVM Hat on the opposite side from the GPIO.

Spacers and long screws installed...

Ahh, almost home free! We are now ready to install the case cover. Before you even start the build though; I recommend you play with the case. Take it apart and put it together a few times while it's empty. Get yourself familiar with the process. The top of the case is pretty stiff so you may want to "spring" or stretch it open a little so when you do the final install you're not fighting with it. You want to make sure you line it up correctly so as not to damage the antenna stub as you line it up and put it on...

Here it is half-way on. See those "slots"? There are tabs on the ends of the bottom portion of the case that fit into them as you slide it on. These hold the top of the case in place. You kind of have to "spring open" the top case as it slides down over the tabs. This is why I recommend playing with the empty case in preparation of putting it on at the end w/out damaging the internal components you just installed.

Ahh, groovy. The case top is on, you didn't F-up the antenna stub putting it on. You're golden... and feeling pretty damned good about yourself and as well you should...

At this point, you may screw the antenna on. If, at a later date you need to take the top portion of the case off; remember to remove the antenna first. Oh and, do you see the micro usb receptacle at the far right? That is where you'll plug the power supply cord in. The other two receptacles (One Micro-HDMI and another Micro-usb) are not used as part of the HotSpot. NEVER plug the power supply into the middle micro-usb receptacle. That's baaad Ju-Ju. Nothing good will come from it.

There it be...in all it's glory. It's almost like you're some kind of electronics engineer...walking around your desk with your chest all puffed out shouting "That's right, I built that bad boy!!" ;-p

The Micro-SD card. This is what holds the Operating System - "Pi-Star". You will want a "U3" card that's at least 16gb in size. While Pi-Star will run on an 8gb card, I recommend 16gb minimum to account for the space that software updates and the digital contact list will eat up that shows people's call signs on the display etc. The bottom pic is of a 64gb card which is waaay bigger than you need but I picked them up because they were crazy cheap on amazon and they came with the SD adapter. Here's a link: https://www.amazon.com/dp/B07ZD8JZZT?psc=1&ref=ppx_yo2_dt_b_product_details

We'll go over installing the operating system onto the card & configuring it in another tutorial. For now let's pretend we did.

The Micro SD card goes in this slot right here; copper contacts on the card facing down towards the board...

Here's the card sticking half-way out. You'll want to push it all the way in of course. When/if you need to remove it, steal your Wife's tweezers out of the bathroom drawer. It makes it much easier to get it out instead of fat-fingering it. Remember to put the tweezer's back so you're not on her Sh!t list. You know how Wifey's get when they can't do their eyebrow pluckin' because their tweezers have gone missing...

Plug the power supply in, flip the switch on the cord and Voila! You're now the King of the Digital Airwaves!

Ahh yes, the pieces & parts list:

The case & MMDVM Hat combo: https://www.amazon.com/dp/B07Z8YP5VJ?psc=1&ref=ppx_yo2_dt_b_product_details

The Pi-Zero board: https://www.amazon.com/dp/B07W3GJTM1?psc=1&ref=ppx_yo2_dt_b_product_details

The 16gb Micro SD card if you already have an adapter: https://www.amazon.com/dp/B089DPCJS1?psc=1&ref=ppx_yo2_dt_b_product_details

Pi-Zero power supply: https://www.raspberrypi.org/products/raspberry-pi-universal-power-supply/ (You can get this on amazon as well. Raspberrypi.org recommends it be a 2.5amp PSU cord).

Hey, let's face it. Not everyone wants to build their own. While it may have been fun to see how the sausage is made; building a Pi HotSpot may not be your thing.

In that case, I got ya covered: https://www.amazon.com/All-New-Hotspot-Assembled-Station-Raspberry/dp/B08JG9MG6Q/ref=sr_1_11?dchild=1&keywords=Pi-zero+MMDVM&qid=1618455762&sr=8-11

If you go with the pre-built option above, I'd recommend going with a power supply that is made by Cana or raspberrypi.org and trash the one that comes with the unit.

As mentioned earlier, this is just the build steps for the unit itself. Next time, we'll go over the installation of Pi-Star on the MicroSD card and configuring it properly to talk to your radio and connect to the digital network.

The radios he makes labels for at the moment:

I am not.

I never will be.

If you are one of these people; don't waste your time calling me. Find some dolt to ply your trade/scam on. You're getting nowhere with me.

In short, F OFF!

Guide to Understanding Static & Dynamic Talkgroups

Posted byu/TheRealTitleist

Some of the most common questions I see posted here are regarding dynamic & static talkgoups, and what that means for actually operating your DMR radio. It's a concept us old grizzled DMR veterans know so well, yet we don't often stop to think about the new operator trying to understand an unfamiliar concept within the mode and hobby.

I will attempt to break down these concepts and place them into real world scenarios, in the hopes that future operators can read and understand how they work. I am not a DMR expert, but I am a big fan with some decent experience in the mode and some great teachers.

About me - I own and operate a DMR repeater in the state of Michigan, a Motorola XPR8300 running on UHF. I'm one of the NCS for the MichiganONE Statewide DMR Net and have a dozen or so DMR radios. I've had the pleasure of traveling around the state to give presentations on DMR and why it's the best mode in amateur radio hands down.

Overview

First of all, it's important to understand that the concept of dynamic or static talkgroups exists only within the scope of a repeater or hotspot. From here forward I will generally refer to these as just repeaters but understand it's interchangeable. Anything I discuss about repeaters is also applicable for your personal hotspot, which is just a mini repeater of sorts. This goes without saying, the concept of D & S is not applicable for simplex operation.

Second of all, it's equally important to understand that the availability of a TG (e.g. dynamic or static) is simply how it's configured on a repeater. In other words, the concept of a dynamic vs static has to do with HOW and WHEN a talkgroup is active on a repeater. It does not have any bearing on how an operator transmits to a TG, just on when they can hear a TG on a repeater. We will however discuss later the impact that has in the context of transmitting.

• Only pertains to repeaters / hotspots
• Refers to how a TG is configured on a repeater
• Only pertains to how the operator receives TG traffic

Static

A static talkgroup is one that is "always on / always active" on a repeater. This means that if a TG has traffic, your repeater or hotspot is transmitting that outward for you to receive. These cannot be turned off by users, and requires the repeater admins to make changes. This has several uses, namely as a way to link several repeaters together to form a wider area network, or to signify a TG has some kind of importance to a repeater.

• TG is "always on"
• Cannot be disconnected by users
• Easy way to always monitor a TG
• Great way to link repeaters over the network

Dynamic

The alternative to static, a dynamic talkgroup is one that is "user activated". It will not be active until a user selects the TG channel on their radio and "keys up", thus initiating traffic. This TG will now be active, but only for a limited time. Generally speaking, a dynamic TG is active for 15 minutes from the last time a user keys up or until a user sends a disconnect code over the air. It's important to note, if you are having a QSO on a TG that has been dynamically activated, it will not time out until you stop transmitting - that's when the clock starts ticking.

It's also important to note that a repeater can have multiple dynamic TG's activate at any one time. In theory, you could have 10 dynamic TG's active at the same time, although I don't recommend this. In this scenario, the repeater handles traffic in a first come, first serve manner. This can lead to traffic being missed as each timeslot can only transmit traffic from one TG at a time - the other 9 are out of luck.

• TG must be user activated
• Multiple dynamic TG's can be active
• Can be disconnected by users
• Typically times out after 15 minutes

In Practice

As an example for how these work in a practical setting, I'll use my DMR repeater. As it's currently configured, it has Michigan Statewide (3126) as a static talkgroup on TS1, and extended local traffic on TS2. If there is any activity on either of those TG's, it's always transmitted from my repeater. I also allow for users to dynamically activate any BrandMeister talkgroup they would like on TS2.

This means that what I deem as the most important TG's to have (the statewide TG and the local TG) are always on the repeater BUT if a user would like to activate US Nationwide or Worldwide they are absolutely able to do so on TS2.

Transmitting

Now that you (hopefully) understand the difference between static and dynamic, let's discuss what that means for you as an operator looking to join into a QSO or call out on a TG. This is critical - regardless of a TG being static or dynamic YOU MUST HAVE THE TG CHANNEL SELECTED ON YOUR RADIO! Just because a TG is static, does not mean any traffic into the repeater on the timeslot is routed to the talkgroup. Every single transmission on DMR requires a target TG, meaning the channel of your radio must match where you intend to transmit.

Let's walk through a real life example to help illustrate this. Let's say your local repeater has TG91 set as a static talkgroup. As you are listening to this, you hear a QSO you would like to join. You pick up your radio, and notice the channel is set to TG3100. If you were to key up and announce your call sign, you would be speaking on, YOU GUESSED IT, TG3100 and NOT 91 as you intended. You would have to change the channel on your radio to TG91 and THEN key up.

(D-Star trigger warning) This is much different than D-Star or Fusion, in that if a repeater is linked to a reflector or room, any traffic into the repeater goes to said reflector or room. DMR absolutely does not work in that way - every single time you press the PTT button traffic is routed to the channel talkgroup on your handset. Period. Regardless of a TH being static or dynamic, you MUST have the intended TG channel selected on your radio.

Yep, I did it. I bought another AT-D878UVPRO. It's so nice, I had to buy it twice... It truly is one of, if not thee best DMR HT's on the market today. It has more bells and whistles than you can imagine; many I'll probably never use. I hate communism and the communist ideology. You'd have to be a raving fucking lunatic to want a socialist society in any form. Having said that; they made a damn fine radio.

Hey, I thought I was gonna chronicle my DMR journey? I know...wait. It's coming shortly.