outdoors hunting camping SHTF GMRS radio communications antenna battery electronics scanners digital computer software hardware laptop iPad iPhone eBay music radio
.

Ham Radio - Camera - Computer - F8HP - UV5R - Baofeng - Pofung
 
Product Review
 

 

DMR   C4FM   D-Star
UHF  hotspot

 
by: John  'Miklor'
December  2016

 


 
  
What is a hotspot?
 
A hotspot is an interface that allows you to connect to a digital network directly without the need of an actual repeater. There are several variations of hotspots available. Some may require your PC or Raspberry Pi interface, but the SharkRF openSPOT is a small standalone IP gateway that connects directly to your internet router via the Ethernet connection. No other equipment required.
 
The openSPOT was developed by two hams that not only understand what hams want, need, and enjoy, but know how to make it work with minimal setup. With features not found in other hotspots, the bottom line is, they did it right.
 
So, here's my take on openSPOT...
 
 
What's In the Box
 
-   The SharkRF openSPOT
-   120-240V / 5V 1A  wall supply
-   USB / micro USB power cable
-   Small UHF antenna (SMA-Male)
-   39" (1m)  Ethernet cable
 
 
Basic Specifications
 
Chassis Size: 2.75 x 2.5 x 1.0"   (71 x 67 x 31mm)
Weight:  5oz  (150g)
Power consumption: max. 210 mA @ 5 V (1.05 W)
RF power output: max. 13 dBm (20 mW)
Receive/transmit frequency range: 421-458 MHz
          (JP version: 430-440MHz)

 
 
Enclosure

 

To start, the openSPOT is a very solidly built unit.  Don't let the size fool you.  The chassis size is only 2.5 x 2.75 x 1.0", but the weight is 5oz.  This is due to the weighted base plate inside
the enclosure to stabilize it when the cables are connected.  There is no heat build up inside, which allows me to run mine 24/7. The antenna jack is a standard SMA-F, with the antenna terminating with an SMA-Male. Four small rubber feet assist in keeping the chassis stable.
 

  
The Manual
 
The openSPOT manual never goes out of date because it's web based. The instructions and tutorials include both graphics and videos to guide you through the entire setup. As new features are added, the manual is updated online, so it's never out of date.
 
 
Setup and Interface
 
To set up the openSPOT, I connected it to the USB power source and my WiFi router using the supplied Ethernet cable. The openSPOT has two internal micro-controllers, designed to use a web based interface. Once connected to my WiFi router, the openSPOT was accessed by simply logging into //openspot.local.  I didn't need to load any additional software or drivers. Everything is self contained.
 
At that point, all that was necessary was to enter:
-  The operating mode (DMR, C4FM, D-Star)
-  My callsign
-  My DMR ID (available from DMR-MARC)
-  The desired server
-  The input and output frequency of my handheld
Note: The openSPOT allows you to select two different frequencies if desired.
After that, a 30 second calibration, and I was on the air.
The LEDs give a clear status indication during operation.
 
Once configured, time slot, trunk group, etc. information is controlled by your handheld. You set it, and forget it. 
 
 
Cross Mode Operation
 
The openSPOT has cross mode capability, allowing a DMR transceiver to access C4FM, as well as  C4FM access to DMR.  This allows you to operate both modes with one handheld. I personally haven't ventured into the cross mode operation, but understand it works perfectly.
 
 
OTA Audio Quality
 
This is where the openSPOT excels. In the past few months, I have learned to identify some hotspots by their robotic audio, much like R2D2 and BB8.  I can honestly say that I have never heard  an openSPOT with less than perfect audio. My reports have been nothing short of excellent.  I use mine on a daily basis, and have had absolutely no issues.
 
 
Firmware Updates
 
The openSPOT firmware is totally upgradable.  Periodically, SharkRF will post FW Beta versions on their site, however my personal preference is to wait until a final version is posted.  I do, however, like to review what is included in the beta versions to get a glimpse into the future. The developers are constantly keeping up with network changes so you always have the latest version.
 
 
Dashboard
 
One of the more recent firmware updates includes a complete status dashboard. This displays all information on the current active channel including the Talk Group, User ID, Callsign and Name of the person speaking by sampling the information in QRZ.com. The information also shows your current static and dynamic Talk Groups.
 
 
Resetting the openSPOT
Part of the FW upgrade procedure requires pressing the tiny reset switch on the back while plugging in the USB cable. To assist with this procedure I fabricated a reset button. It consists of a small Push Pin with the pin cut to approximately 1/8" (3mm). I rounded the tip with a file to prevent damaging the internal switch. It makes pushing reset a one hand operation.
 
 
 
Transmitter
 
The power level of the openSPOT variable up to a max of 20mw. That may not sound like a lot of power, but 1mw is enough for me to hear the signal solidly throughout my entire house.  20mw on an outside antenna will allow you to use a digital radio throughout your neighborhood.

 
 

But how about Mobile Installation

Here's where I became a bit creative. Rather than connecting directly to my router (downstairs), I wanted to see the lights flashing, so I purchased a TP-Link TL-WR802N and set it up as a client to access my in home WiFi. The openSPOT never missed a beat.
 
Why the TP-Link? Well, it is just slightly smaller than the openSPOT, connects via an Ethernet connection, and fits nicely on top of my RAVPower 22000mAh battery. I linked the TP-Link to my Cellular WiFi hotspot and now, instant digital mobile. I also successfully tried a Vonets VAR11N-300 mini.
 
I can get nearly 2 full days from the RAVPower 22000, but I still top it off every evening after use.
 
Now when traveling or on vacation, I no longer need to program a codeplug for every repeater along the way.  I set the radio to mate with the preselected openSPOT frequency, and that's it. I now have access to the worldwide Brandmeister network
 
The entire mobile hardware configuration is approximately 2 x 3 x 6.5" (5.5 x 8 x 16.5cm), not counting a few cables sticking out. The entire configuration fits inside a pencil box.
 
 
 
How much Data

 
The openSPOT uses very little data. Depending on your connector, the data rates are as follows:
Quiet Channel is  36 - 180kB  /  hour
Active Channel is  3 - 6MB / hour

 
So, why an openSPOT

 
Hotspots were not developed to replace repeaters, but rather to supplement them. In areas where there is No repeater, a hotspot allows the user to connect directly to a digital network via the internet. In areas of Heavy repeater use, a hotspot allows the user to access the network without competing for an available time slot.
 
If your local repeater gives you access to a network such as DMR-MARC, an openSPOT can give access to networks such as Brandmeister. You will now have access to the best of both worlds.
 
 
Summary
 
DMR repeaters are being placed in service daily, but currently there are only around 800 repeaters in the US.  As for me, I am 25 miles away from my two nearest repeaters and require an outside antenna to reliably use them (and I'm one of the lucky ones). In some areas of the country, digital repeaters don't exist.
 
The solution quickly became obvious. To enjoy the freedom of a handheld, I needed the help of a reliable hotspot.  After listening to several configurations over the past several months, I am convinced daily that I definitely made the right decision with an openSPOT, with everything I need condensed into one small standalone package.
 
 
SharkRF -  Home Website
SharkRF -  Purchase
 
TP-Link 802N
 
RAVPower 16500
 
RAVPower 22000  (Best Value)
 
RAVPower 26800
 
RAVPower 32000

 


 
 
 

TOP of PAGE
 
Miklor Home
 
Miklor
 


   




DMR