Linked System Back In Service

After many months of varying states of operation, I’m happy to report the SMRC linked system is back in full service tonight. Thanks to the hard work of many of our members, we’ve got a fully functional system. A few notes on the current state of the system:

  1. The system is currently linked for analog FM use only. Each individual site repeater is set to use AMS (Auto Mode Select), so digital operations through a single repeater are possible (and work quite well, I might add); however, we are still developing a digital linking system for all three sites. Analog FM users should set a PL tone of 151.4 on both transmit and receive, as well as enable BCLO (busy channel lockout), if able, to keep from hearing/stepping on digital users.
  2. The main antenna at Alamo Peak has temporarily been removed from the tower until it can be properly remounted. The broken sidearm mount has also been removed from the tower. In the interim, a secondary antenna is being used with about 6dB less gain, so users in canyons or at the periphery of coverage are most likely to notice the impact. Plans are underway to remount the main antenna this coming week, so full service should be restored quickly.
  3. The audio gain on the Weed link radio needs to be adjusted. Users going through Weed will notice very high audio gain on TX/RX. We are aware of the problem, but will have to schedule a trip to the site to adjust the radio. The system is still usable via Weed, but if transmitting through that site, move the microphone a few inches further away from your mouth than usual. If it’s untenable, use the James Ridge repeater, if able.
  4. Once items #2 and #3 are accomplished, we will begin efforts to digitally link the system. The initial phase of that effort will involve linking the James and Weed sites via 2.4GHz microwave. Linking Alamo to the system will be a much more challenging problem. We are currently researching IP link radios in the 433MHz spectrum to execute this operation, but finding radios with enough gain and bandwidth to accommodate the digital link has proved difficult. Improvements in the bandwidth of LoRa systems may bring a viable solution in the near term.

The current state of the system is posted under the Repeater Info section of this site, so if you are new to the Club, or have had your machines programmed to use alternate PL tones during the interim status of the system, review your radio programming to ensure it matches the information here on the website.

Thanks again to everyone who has/is playing a part in getting the system back up to speed, and thanks to Club members for their patience while we have sorted through many technical issues. Watch the website for an upcoming multi-part write-up documenting the process we’ve gone through to get the system back in working condition.

System Upgrade Interference

Since last weekend’s system upgrade, you may have noticed interference on the repeater system from Mexican taxi drivers. We believe we have narrowed down the interference to the 70cm link radio at Alamo Peak. Plans are in work to reprogram the link radios on the system this weekend to eliminate the interference.

Users of the James or Weed repeaters may also notice significant receive audio degradation from users entering the system from Alamo Peak. We believe this is due to the last minute substitution of an out-of-band link radio at James Ridge after discovering the primary link radio had experienced catastrophic failure in the PA circuit. A replacement radio is on order and the planned site visits this weekend to reprogram the link radios will also include replacing the under-performing link radio on the Alamo-James link, provided the replacement radio arrives in time.

Please note any other performance or audio issues you experience with the upgraded system and notify me via email.

System Update

As of 2000 MDT tonight, the SMRC club radio system has been upgraded at all three sites with Yaesu DR2X repeaters on 2m. The upgrade should correct the issues the system has been having with the link radio at James Ridge, and analog linking was tested across the whole system with no issues noted.

The upgrade also brings C4FM to all three repeaters sites; however, digital linking is still a work in progress. Each individual site will repeat both analog FM and C4FM transmissions, but only the analog transmissions will link to all three sites.

NOTE: As part of the system upgrade, the PL tones to access all three system repeaters has changed to 151.4 Hz. Regular users of the system will have to reprogram their radios to reflect this change.

An additional part of the upgrade was adding a PL tone on the output of each repeater. Analog FM users who do not want to listen to the audio of digital system users can simply set a PL tone of 151.4 on their radio receive, as well as transmit, and it will prevent any digital signals from breaking squelch, as digital is transmitted from the repeater with no PL tone at all. In addition, users who have a Busy Channel Lockout (BCLO) feature on their radios are encouraged to use that feature, as it will prevent analog and digital users from transmitting on top of opposite mode transmissions.

The Repeaters section of this website has been updated with the new repeater programming data, so reference that page for detailed information on system configuration.

Note any issues with the new system over the next few weeks and be prepared to discuss at the September club meeting.

Thanks to Bill, KI5J, for his assistance in getting everything transitioned to the new repeater radios, as well as the technical work behind the scenes to make it happen. Enjoy the new radios!

Remote Linking Update

After a trial implementation with SMRC system remote linking using the AllStarLink network, some additional improvements need to be made to the system to facilitate external connectivity.

Due to the legacy configuration of the repeater system and the up/downlink configuration of the experimental AllStarLink node attached to the system, telemetry tones from the James Ridge repeater are passed over the link to Alamo Peak. The net result of this is that telemetry tones for the system are passed over remote links such as AllStarLink and Echolink, which is an undesired practice. Proper repeater system configuration is a system where each individual radio (primary or link radio) emits telemetry without associated tone encoding which prevents the telemetry from being repeated over other radios in the linked system when combined with proper CTCSS settings on other system radios.

Correcting this issue may be paired with a more advanced technological solution which enables CTCSS coding to be used to allow C4FM and analog FM users of the repeater system to both enjoy use of the system without causing unwanted end-user radio traffic to users of the opposite modulation scheme/mode. Integrating an advanced repeater controller at each site will allow multiple CTCSS tones to be used on repeater transmit based on the type of modulation used. End-users can then implement a receive CTCSS (available on virtually every modern FM transceiver) to prevent squelch break unless a received transmission is accompanied by the CTCSS tone suitable to the mode being transmitted.

This functionality is currently being implemented on the Alamo Peak transmitter in a slightly modified manner. Analog FM users who normally monitor the Alamo Peak repeater may filter out unwanted digital transmissions by setting a receive CTCSS of 151.4 Hz in additional to utilizing the normal transmit CTCSS of 151.4 Hz used to access the repeater. C4FM digital transmissions from Alamo Peak utilize no CTCSS tone, and C4FM receivers do not break squelch on receipt of analog FM signals, so mode isolation is currently possible for both C4FM and analog FM users on the Alamo Peak repeater.

Unfortunately, C4FM is currently passed over the system link to both James Ridge and Weed repeaters without the ability to CTCSS segregate those signals. The C4FM is passed through the audio section of the link radios, and as such is not decodable by other C4FM receivers, but is also unable to be filtered using CTCSS tones. As we upgrade the repeaters at James Ridge and Weed to the DR2X multi-mode repeaters, this problem will be corrected and in its final configuration, the system will facilitate co-use by both analog and digital users with minimal interference to each other.

A repeater controller which allows mode segregation via CTCSS tone will also allow the use of non-tone encoded telemetry data, which will make the implementation of analog linking services such as AllStarLink and Echolink clean and technically correct. Stay tuned as we work to implement this solution in coming months.

Experimental AllstarLink On-Air

If you’ve been hearing more than the average number of DTMF tones on the repeater system lately, it’s likely because an experimental implementation of AllStarLink is now running on the SMRC linked repeater system.

AllStarLink is an analog FM linking capability which uses on-air DTMF tones to connect & disconnect from other system nodes via the internet. For those familiar with Echolink, AllStarLink provides similar functionality at a basic level, but allows some significantly more complex configurations when fully integrated. In fact, once the AllstarLink system is fully implemented, the SMRC repeater system will provide both Echolink and AllStarLink connectivity.

The experimental implementation provides basic AllStarLink connectivity. The following control codes can be used to interact with the system:

  • *3 + ASL Node Number = Connect to remote node
  • *2 + ASL Node Number = Connect to remote node (monitor only – no transmit)
  • *1 + ASL Node Number = Disconnect from remote node
  • *721 = ASL Link Radio ID
  • *722 = ASL System Current Time
  • *806 = Disconnect all links

Users are encouraged to test the system and provide feedback via email to my call at Adjustments to system audio, implementation of location announcements, periodic audio QST’s, Echolink implementation, and a nationwide VOIP autopatch are just a few of the system capabilities currently in work.

For a list of nodes to which you can connect, visit the AllStarLink node list and look for node numbers listed in green squares. A filter function at the top of the list allows you to search for specific callsigns, node numbers, and locations.

Have fun with AllStarLink, and watch this news feed as we bring more features to the system in the near future!



As of 12:30pm this afternoon, the full linked repeater system is back on the air for analog FM linking. I took a trip to Alamo Peak this morning to see if the road was passable. The short answer is … “barely”:

Alamo Peak Road

There is still about 24″ of snow on the ground around Alamo Peak, and several additional inches were dropped yesterday afternoon. I was able to crawl my way back to just short of the comm site turnoff. All stranded vehicles on the road have been removed; however, there is still a significant amount of ice under the snow, which made driving an exciting activity.

Due to the snow depth, I had to hike from Alamo Peak Road in to the repeater site:

Hiking in to Alamo Peak comm site

The ice on the snow was thick enough to hold my weight, which actually made the hike easier than I had planned.

Once at the equipment shed, I quickly installed the coupling cable from the DR2X repeater to the Radius link radio. The homework I’d done previously finally paid off. A quick comm check with K5WAZ proved the Alamo Peak machine was linked both ways with James. A subsequent check with KG5VIN confirmed the two-way link between Alamo Peak and the Weed repeater.

Now that we have a working, standardized DR2X configuration at Alamo Peak, my next efforts will be to construct “install-grade” cables for all three sites, and program a Motorola link radio to replace the TKR-850 at James Ridge. Once I have those two tasks done, replacing the legacy radios at James Ridge and Weed should be a quick task, and will bring C4FM access to the rest of the system.

Thanks to K5WAZ, KG5VIN, KF5VLJ, and KG5DAC for their help in getting the system back up and running. As always, if you have any issues with the repeater system, please shoot me a text or email and I’ll see what I can do to work the problem. 73 and see you on the linked system!


Alamo-James Analog Link Update #2

After several attempts to get the link back on the air, we are moving closer to success.  Extensive experimenting has shown that using a pair of DR2X repeaters for the system/link radios is not a preferred solution due to full-duplex looping issues on the link.  As such, we are returning to the classic configuration of a DR2X 2m radio and a Maxtrac link radio.  We had success keying this configuration on Saturday; however, we are still attempting to resolve the best way to pass audio between the machines.

On a related note, there is a possibility that we can add multi-mode digital voice to the Alamo Peak repeater with minimal cost:

Zebra MMDVM Pi3 Case - Raspberry Pi 3 B+ and MMDVM Pi ~ Black Ice - C4Labs
The MMDVM-Pi Digital Modem

MMDVM-Pi is a multi-mode digital modem which uses a Raspberry Pi computer and a simple $99 Pi-Hat to enable a radio (or repeater) to function as a gateway to DSTAR, DMR, System Fusion, NXDN, and P25 digital voice networks via the PiStar software interface.  With an Internet uplink to the Alamo Peak site, the repeater can be used by digital radios on any of the above networks, bringing a tremendous capability to the Alamo Peak repeater.  Additionally, initial research indicates that it may be possible to link all three system repeaters to take advantage of the capabilities of this digital modem.  Stand by for updates as we investigate the possibility of integrating this modem into the Alamo Peak repeater.

Alamo-James Analog Link Update

The analog FM link between the Alamo Peak and James Ridge repeaters has been tentatively restored. Full testing of the system has not been accomplished, so fully functioning operations have not been verified; however, the comm paths I could test from Alamo Peak were checked this afternoon. The following results were observed:

1) Transmissions into the 147.220MHz repeater were re-transmitted on the 440MHz link w/ the proper PL tone.

2) Transmissions into the 147.340MHz repeater were re-transmitted on the 440MHz link w/ the proper PL tone.

3) Transmissions directly into the 440MHz link machine at Alamo are repeated on the 147.220MHz repeater.

I was unable to test an end-to-end transmission from Alamo-James or the reverse on 2m due to reception/transmission limits at the site from HT/mobile transmitters, so if anyone is able to verify the link is working, please send me an email detailing the experience. Also, I was unable to test the Weed repeater as part of the link, so any feedback on the whole linked system would also be appreciated.

I left the Alamo Peak 2m machine configured as an AMS repeater, so C4FM users should still be able to utilize Alamo; however, a functioning digital link from Alamo to James will be a bit more of a technical challenge…one which I continue to pursue.

Once I verify that the link is working again, I will replace the Kenwoods at James Ridge with the other two Yaesu machines, which will bring stand-alone C4FM capability to James in addition to Alamo Peak.

Once Alamo and James repeaters are swapped out, the plan is to install a 2.4GHz microwave link from James to Weed and upgrade the Weed repeater to a C4FM machine. With that configuration, we should have a working C4FM link between those two repeaters, as well as traditional analog linking.

In parallel, I am working to install an HRI-200 WIRES-X interface at Alamo Peak and downlink to a low-level internet connection. This will bring the Alamo Peak machine a capability to internet link to other YSF nodes/rooms around the globe. In conjunction, I will also establish an SMRC “room” which works in a very similar manner to a packet BBS – it provides a central place for C4FM users to connect to view news/message traffic, pictures, and voice memos which can be uploaded from any user to be viewed by all in the “room”.

Thanks to all for your patience as we work to put the system back together. It’s been quite a journey, but we’re slowly making progress.

Alamo Peak Repeater Online

The Alamo Peak 2-meter repeater has been returned to service as of this afternoon. The link to the rest of the SMRC system is still being configured, so the machine operates as a “stand-alone” unit until the remainder of the configuration is complete.

The old Kenwood TKR-750 machine has been replaced with one of the new Yaesu DR2X repeaters, bringing C4FM digital voice as well as traditional analog FM voice to the mountain. As such, a few things have changed with respect to accessing the Alamo Peak repeater:

1) The repeater retains analog FM repeat capability; however the PL tone on the machine has been changed to 151.4 Hz. If you have a radio with a programmed channel to access Alamo Peak, please re-program your radio to accommodate the new PL tone. In addition, the repeater now has a PL tone of 151.4 MHz on the repeater output, allowing users to implement a tone-coded squelch setting on their radios.

2) The repeater now has C4FM digital capability. To access the C4FM service, the normal repeater frequency pair is used, but with a DCS code of 051. The repeater is currently set to AMS mode on the input, so the machine should match repeat either type of incoming signal.

We are working on restoring the link to the rest of the SMRC repeater system; however, due to some technical limitations, the fix for the link is still several weeks away.

Users noting any problems with the new Alamo Peak repeater are requested to contact one of the club officers, or a member of the repeater maintenance committee.

Alamo Peak Status

The Alamo Peak repeater is currently offline due to a lightning strike on the mountain this week.  Bill & Mickey visited the site this morning and investigated the problem.  The solution will require replacing both radios at the site.

I am currently building a repeater pair using the new Yaesu DR2X machines which will replace the Alamo Peak radios.  I will also build a pair to replace the James Ridge radios.  This will finally bring C4FM to the Alamo & James machines.  The analog FM link to Weed will remain operative, but ultimately the Weed machine will also be replaced with a C4FM repeater bringing the whole system up to 21st century standards.

Until the Alamo system is rebuilt and the new equipment installed, that machine will be down.  The James & Weed machines remain operative.  Expect the Alamo machine to be  down for at least two weeks before we can get back up to the site and swap out the hardware.  In the meantime, the 145.230 MHz machine on Benson Ridge, the 145.350 MHz Mega-Link machine on Long Ridge, and the 147.000 C4FM machine in High Rolls are viable substitutes for the Alamo Peak system.