August Engineering Committee Notes & August Work Day

During the month of August, the Engineering Committee was working hard to make sure we bring you the best repeater system in the St. Louis area! Here are some of our accomplishments in the past 30 days.

During our scheduled engineering work day (2nd Saturday of each month), we removed a spare two meter 4 bay dipole antenna from the west side of the roof at the 9666 Olive Blvd site. This spare antenna was installed to test the coverage area for the 146.850 repeater many years ago, but turns out this antenna location was almost deaf in the 2m band as there is a transformer on the other side of the wall inside the penthouse producing horrible QRM ( AKA interference). This antenna will make its new home, at the end of September, at 665 Skinker Blvd (146.970 repeater) atop a 27 story building just west of Forest Park.  Hopefully this will clear up any water and antennas issues we have been experiencing.

At the 200 S Brentwood Blvd site (146.940 & 442.100 repeater) , Steve (KEØDWB) installed the recently purchased Yaesu DR-2X running in AMS mode and Joe (WØFY) re-programmed the CAT1000 controller for the 440.100 machine. The DR-2X upgrade will be the first digital repeater in our linked network via our 5Ghz wireless network. As we upgrade additional DR-1X’s with DR-2X repeaters in 2019, we will build out this digital network in the STL area. More info to come on how this digital network works, but if you want more info now, there is a Yaesu Webinar YouTube link at the bottom of our SLSRC Repeaters & Nets webpage explaining C4FM and IMRS linking. The goal is to be able to carry a digital conversation on a SLSRC C4FM repeater with an HT anywhere in the STL Metro area.

While Steve was upgrading the 146.940 repeater, Joe re-programmed the existing controller for the 442.100 repeater to make it an exact clone of the controller we have running the 146.850 repeater. We have standardized on features for the CAT1000 which makes it very easy to swap out if we need to replace in case of a failure. The swap includes racking the new controller, adjusting the input and output levels and you’re ready to roll!

The committee also performed site maintenance at the 200 S Brentwood Blvd site during the month of August. We will eventually replace the duplexers at the 146.940 repeater with smaller 4 cans and use the 6 cans installed there now as spares. The 6 can duplexer is in need of a re-tune, very bulky and takes up a lot of space. Actually they don’t even fit inside the repeater cabinet. Since we are not running a large amount of power at that site, a 4 can duplexer solution is suitable and frankly more manageable.

In August the committee made a few announcements about the streaming and recording capabilities at the 146.850 repeater. Thanks to Eric (N9RZR) and Michael (KA9CQL) for their hard work and programming skills to make this work. First announcement, we are broadcasting the 146.850 repeater on the internet at You can listen anywhere in the world on basically any internet connected device. Second, we are now recording the SLSRC Tuesday and ARES Wednesday night nets. This is a great way to listen back to your transmission to see how you were getting into the repeater, or if you missed the net and just wanted to listen. Third, we introduced a recording parrot on the 146.850 repeater. This parrot allows you to record your signal into the repeater and playback instantaneously via a web browser. This is a great way to check out your rig, troubleshoot antenna issues or just see how others hear you on the repeater. All these links are on the SLSRC Repeaters & Net homepage.

The committee is looking forward to a busy September. Some of the items we are working on:

  • We are testing out an All Star VOIP solution with Raspberry Pi’s for linking the repeaters together and to provide a clearer sounding internet linking solution.
  • We started internal discussions about the AREDN mesh network and how the best way to build this network out in the STL metro area.
  • We agreed upon a proposed 2019 budget which positions the club for continued upgrades to the repeater systems, more digital systems and new features like dynamic linking to allow anybody in the STL to hit a SLSRC repeater with an HT (both analog and digital) during times when the repeaters are linked together.
  • At the end of September we will bring on the SLSRC APRS digipeater and iGate node online at the MoBAP location. This will broadcast out all our repeater systems as objects on the APRS 144.390 frequency and iGate to the APRS-IS system. It will also provide APRS coverage in West County area.
  • We rescheduled the 2nd Saturday engineering work day for Sept 30th at the 146.970 site because of Bike MS and will be completing the following during the work day.
    • Upgrade the Vertex 5000 repeater to a DR-1X Fusion running in AMS mode
    • Replace the coax from the duplexer to antenna with LMR 400
    • Replace the antenna from a dual band fiberglass to an Andrews DB-224-E aluminum antenna
    • General maintenance and duplexer can verification

If you have questions about the Engineering Committee or want to help volunteer, please see Kyle, AAØZ either at the next SLSRC club meeting, or shoot me an email via my QRZ page.

Below are pictures from the August engineering work day.

[Best_Wordpress_Gallery id=”22″ gal_title=”Aug 2018 Engineering Work Day”]