SharkRF openSPOT” – Block Diagram


The “hot spot” is becoming mainstream in Ham Radio (a virtual repeater on the Internet). When this virtual repeater is accessed, the assigned reflector relays the transmissions to the access station, so you can listen to the communication of all the stations participating in the reflector, you can also call and communicate. The recent popularity of reflectors can not be overlooked by the fact that amateur stations in the world that can connect to the Internet can communicate with each other where in the past a repeater was needed.

With many digital repeaters shut down in the GTA, many hams have reached into their wallets for new gadgets to make QSOs with. The bonus is the Hot Spot is also perfect for travel. Make contacts on your favorite digital mode while on the beach in Bahamas. Many hams are gettinga MD-380 DMR handheld and a hotspot and now can access the world through brandmeister networks.

What is a hotspot is
Generally called a wireless LAN access device, a Wi-Fi gateway, a free spot, a hot spot or the like, which can be received from the access point.

SharkRF openSPOT
openSPOT corresponds to DMR, D – STAR, C4FM, Fusion mode. The package includes the main unit, AC / DC power adapter, Ethernet cable, antenna, card with URL of user manual.

I have included a block diagram for the Advanced Hams to look at. The core is the RF Transceiver narrow band ADF7021 chip that handles the transmitter duties with a wopping 20mw output. As many know this power output can provide coverage of several hundred square yards. Experiments have proven longer distances over line of sight. The TXCO provides the much needed frequency stability needed at higher frequencies.

I have looked at the various spectrum analyzer displays using my portable tool to look at the difference between a D-Star, C4FM and DMR output.

One could actually determine the signal modulation by the display reading.

Shark RF Blocks

I am posting the excellent guide for new hams looking to explore the world of DMR radio

dmr sweep






  1. ve7hamradio · June 1, 2018

    Reblogged this on Coastal Ham Radio.


  2. ve7fky · June 1, 2018

    Reblogged this on VE7FKY’S Blog.


  3. Mike Hohmann · June 2, 2018

    Thanks much, John. I picked up a TYT MD-9600 a couple of weeks ago -was a good deal! I got it programmed and tested it a bit w/ a friend. I’ll have to review the DMR pdf material. Been too busy to do much of anything. Several friends have the MD-380. Your reference to the ‘Shark hotspot’ caught my eye. Much appreciated.


    • ve3ips · June 4, 2018

      DMR is a lot of fun and a new mode to explore. The hotspots and a radio in a hotel room anywhere in the owrld or a Starbucks with Wi-Fi means QSOs


  4. ve3ips · June 6, 2018

    Welcome to DMR the Shark does not have wifi just ethernet connectivity but I have the zumspot as well. It has wifi

    Use wifi anywhere to connect to the dmr network to make qso check HRO they sell both


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s