Bridget - a MMDVM Portal into PNW DMR

A publicly available MMDVM server (Peter) is now available for hams outside of our regions who have an MMDVM client device and wish to have access directly into our c-Bridge network.  Our other MMDVM servers are for use by our regional members only.

The MMDVM project has gotten a boost as more servers and Linux/Python savvy hams have volunteered to help.  We now have 2 Bridget servers online as well as Suzy, Bridget's twin, for our users east of the Cascades.  More MMDVM servers are or will soon be available.


Be sure to put Local 9 in your Rx group for all channels in your Bridget zone for both oS annunciation and use as the Local 9 calling talkgroup.  TAC 1, 2 and 8 are now available for QSO's.

Also available is Android or iOS Streaming via Zello.  This is a listen only stream but Zello users are able to talk locally over Zello as well.  This stream mirrors the Bridget talkgroups and any current users timer activities. 

Server Settings for Bridget (MMDVM Server)

Server IP:

Server UDP: xxxxx

Password: xxxxx

Connector:  HotSpot/MMDVM
Protocol: MMDVM

If you find that you cannot connect, check the files for the latest settings (PNW members only)

When setting up your openSPOT, be sure to have the "advanced mode" checkbox checked so that you can enter the server IP and UDP port into the fields and then click Add Server. Do NOT enable "Use DMRplus options". (See: Image 1, Image 2).

If running Pi-Star, you MAY need to open a UDP port in the Pi-Star firewall to run a non-standard port such as is likely here with Bridget. Check out the solution at IO by Stacey KB7YS or read down the page.

Be sure that the "DMRplus options for DMRplus" setting does NOT have the "Use DMRplus options" checkbox checked (see image).



  1. Do you want your create your own MMDVM server? 
  2. Do you want to be able to use your openSPOT or other MMDVM client to connect to your MotoTRBO repeater, c-Bridge peer manager or repeater?
  3. Do you want to use your own talkgroup deck?
  4. If so, check out our set-up page.



Be sure not to put your hotSpot on any repeater output or input/output frequency as it likely will result in looping and render the server useless and busy out a timeslot on the c-Bridge.

We have created a new MMDVM group at DMR  It is for direct support in creating more MMDVM to IPSC "Bridget" servers within a single VM.  If you can provide us assistance (strength in Linux and Python programming, please join us.

We have seen a peak CPU use of about 11% on our busy server.  Good indication that 5-10 instances should be supported by a minimal single core DO droplet.

The UDP port may change from time to time due to outside constant use or misuse.  If a change is made, it will be published in the IO groups but not on the web.  This is to maintain Bridget as a service for PNW DMR members use rather than the world.  We continue to maintain our BM connections on Idaho, Oregon and Washington statewide talkgroups as it provides the best service for us and hams around the world.

We have added a new zone to the PNW CS-580 codeplug to support Bridget.  It also sports RX Groups on 3 channels.  Most users are likely to just listen via promiscuous mode as it works so well in this rather fine HT.  A scan list was not added due to the shortage of available scan lists in the 580 (max of 32)

openSPOTs realistically support only a single timeslot, so even though some of the PNW talkgroups appear on timeslot 2, simply ignore that and use the single timeslot mode on the openSPOT and program your radio for timeslot 1.  Bridget handles the routing to the correct timeslot on the c-Bridge as well as the reverse.

PS 1 and PS 2 are now on Bridge with very long hold-off timers, do not kerchunk these please and you will effectively disable Bridget for 1-2 hours.  PS talkgroups are for EmComm and Public Service Events only.

When you TX through the Bridget server, you appear on the c-Bridge as if you were using a repeater named Bridget (oddly enough).  Use NetWatch to see the activity.  All talkgroups have hold-off timers as shown above so remember that if you ker-chunk one you are turning off many others.  You should ker-chunk again if you wish to listen to a different talkgroup or otherwise wait the typical 2-3 minutes for the hold-off timers to toll.

Local 9 is a valid talkgroup for openSPOT users or other MMDVM clients as well as a few select PNW repeaters.  It enables users to talk to other openSPOT users similar to an Intercom.  Hold-off timers are set to 2 minutes, shorter than normal (really the priority is to get into the PNW network) but long enough not have the c-Bridge activity barge into your active TG 9 conversation.

Please do not use talkgroups that are not listed in the table below.  If you do, they will not pass through the c-Bridge, nor will there be any hold-off timer control.  Worse, you may get yourself banned or blocked from the portal for continued misuse as this activity adversely affects the other portal users.

If you key up on a talkgroup not active in the Bridget TG table, your activity will still show up on NetWatch but the activity will go nowhere.  You may also see "Unresolved" with the talkgroup ID number if that is the case.  If this happens, no hold-off timers will be activated and all c-Bridge traffic will still be active back to the openSPOT.  That c-Bridge activity will stomp on your unique talkgroups.  We ask that you only use talkgroups listed in our table above.

If you need a client bridge to run your openSPOT off a WiFi connection, consider the IO-Gear GWU637, $44 at Amazon.  It is 1/3 the size of the openSPOT.  If you have a 3G/4G USB dongle already, then the TP-Link TL-MR3020, $29 at Amazon is a great option.  It is about the same size as the openSPOT.

The Bridget project is in motion and the talkgroup deck may change so check back here fore the latest information.  BTW, Bluestack devices are not supported.


12-21-17:  We are now able to use a single VM to deploy multiple MMDVM Servers thanks to KI7SBI's Dockerfile implementation.  We will soon publish neophyte level installation instructions and documentation which will enable using a new Digital Ocean droplet as the starting point all the way to setting up 2 MMDVM servers.  But for now, we have our original install page and the mmdvm support at

12-18-17:  The Bridget MMDVM server is no longer public, Peter, our public server is available for use by hams outside of the Pacific Northwest.  Updates will now be made in our IO groups Wiki rather than here.  Updates

12-8-17:  Pi-Star (Zumspot, Nano-Sport, etc) has a tight firewall and must be opened up to use the currently Bridget UDP port.

  • Here are the steps to update the firewall on Pi-Star for the new 51### port:
  • In browser go to pi-star.local/admin/expert
  • SSH Access
  • Log into pi-star (pi-star / rasberry by default)
  • rpi-rw   (set the filesystem to read/write)
  • sudo su -   (switch user to root)
  • cd /root   (change directory to the root dir)
  • nano ipv4.fw   (create a file for custom iptables entries)
  • Enter the necessary information - comments are OK (or can only be just the one line), this is what mine looks like:
  • # Entry for port change to PNW Bridget v3
  • iptables -A OUTPUT -p udp --dport 51501 -j ACCEPT
  • In Nano Exit and Save the file.  You can see if the file is there
  • sudo pistar-firewall   (this will run the update firewall script)
  • If you read through the resulting output at the top of the ipv4 section you should see your entry for port 5xxxx
    Exit out of SSH session              by: Stacey - KB7YS

12-5-17:  The UDP Port was changed.  Please check our Forum files for the latest information.

8-8-17:  The talkgroup deck programming is complete, MCT Off is now optionally needed as this manager is now with fully coded hold-off timers for all listed talkgroups above.  So MCT Off will only add 12 minutes to the existing 3 minute hold-off timers if they happen to be active.  Remember, others may be sharing Bridget with you so what you function is the same for all logged in users.  Check for users via Local 9 if you have any concerns.  We have 8-12 users logged into Bridget at any random time.

8-7-17:  B 2.0 is now working solidly so will begin to expand the talkgroup deck.  OR 1, WA 1, WA 2, PNW 2 and PNW Regional 2 are fulltime to enable Bridget listeners to have something to monitor and maintain some connection to our network.  The plan is to take Bridget private and available only to PNW members and other closely affiliated hams with interest in the project.  Publishing the Bridget how-to will enable other groups to create their own portals.

8-1-17:  Local 9 will be the default openSPOT to openSPOT intercom talkgroup.  This talkgroup tends to be used by most openSPOT users for the server annunciation as well as redirect.  Also channel redirect can be used with Bridget.  So be sure to turn redirect off when switching your server to Bridget if you have the correct talkgroups programmed into your radio.  Also you can simply use redirect but with the correct talkgroup deck as listed above.

8-1-17:  Added the set-up Information to this page.

7-31-17:  Bridget 2.0 is out of beta.  Washington 1 has been added to the deck.  "Unicom" is on PNW Local 1 for all openSPOT user connections if they wish to chat openSPOT to openSPOT. 

We will publish everything soon on how to set-up your own portal.  A test run this morning had a working install up in 7 minutes once the VPS was ready, all done by scripting.  Just 3 simple config files to adjust to your own installation and done.  Again Vance, W6SS has been the lead on getting the major work done to get to this point.  We ultimately hope to be able to handle multiple talkgroup decks going to different c-Bridge managers and different c-Bridges, all from the same VPS (keeping costs to a minimum).  The original servers 1 and 2 will likely go away at some point soon.

7-28-17:  Bridget 2.0 is out!!!  The same TG's are available.  This new VPS is utilizing a variation of the setup used on Bridget 1 and 2 and appears to be bullet-proof.  At least at this early point, all is looking good. 

This implementation was created with the great assistance from Vance, W6SS.  He deserves much credit for providing the assistance here as well as the training needed to manage and re-create the installation from a fresh VPS spin-up (Debian 8.9 x64).  We intend to publish the details and make it relatively easy to deploy this project for other c-Bridge owners or repeater owners who want to supplement their own repeater managers with openSPOT or other MMDVM clients.  More to follow...

7-10-17:  Server 2 is now on 52032 and normal comms have been restored.

7-6-17:  You may wish to update your openSPOT to Firmware v0119.  I had a report this morning that the user had not been able to connect when using v0117.  But on the other hand, I've not had any issue with connections while using v0117.  If you are using older firmware, this may be helpful generally as well.  YOUR MILEAGE MAY VARY!!!

7-2-17:  UDP changed on Server 1 from 62031 to 52031, Server 2 (62032) is unchanged.

6-28-17:  Local 2 works fine for openSPOT to openSPOT users, had a 4 way tonight.  But still some issues overall, so be prepared, this is still in beta with more fixes and changes to come...

6-27-17:  HEADS-UP:  The UDP Ports on Server 1 will be changing to 52031 and Server 2 may be 52032 soon.  If you can't connect, try these also (once you see the setting have changed below).  This is in part, to address those hams who are not able to connect under any conditions on the higher ports.

6-22-17:  62031 Only:  Experimenting with call complete determination timing.  Default is 500 ms (150-1000), first week was 500, now at 150 ms, will extend out to 1000 over some time.  Comments welcome.

This particular project has been in the works for months but is based on the great work of multiple folks going back 4 years or so.  All software is open-sourced and available on GitHub by Cort, N0MJS and his crew of supporters.  Also kudos to and for the fine assistance of Corey N3FE, one of the USA Brandmeister admins who initially shepherded our efforts at PNW DMR.  Also to Vance, W6SS for being the one who coded the installation script (still used by our new use of Docker) and explained how it worked, which is instrumental to enabling Linux neophytes to be able to install and manage their own MMDVM projects. And finally to Dylan KI7SBI, who put this project inside a Dockerfile to enable multiple MMDVM servers to reside on a single VM.

The partner programs used are:  dmr_utilsdmrlink, hblink and Docker.


Revised: 12/23/2018 08:21