The Cabinet Project
Rebuilding a great repeater site
Photos by Ken Wing WB6IVK
Skip to April 5th Latest Photos of the project.
If you have been reading this newsletter for any time you have no doubt heard mention of the project to replace the Mt Veeder repeater equipment. The owner. Ron, W6BIS had decided to add some very significant additional features to the system and the existing cabinet is just too small. The photo was taken only two weeks ago and already another antenna has been added to the tower. On March 22nd yet another antenna will be placed, for a VHF repeater as well as one for a new D-Star repeater, coming soon.
Ron took a few of the SARS members along on a recent trip to the repeater site and that gave Ken an opportunity to take some pictures. Here's the way the system looked at the time. The cabinet has been unbolted and is temporarily tied off to the tower. After the next antenna job, it will be rotated around the tower to make room for the new cabinet.
Pictured (l-r) KO6FR, W6BIS, AE6W, KI6GPN
In this photo, Ron is working on some equipment on the back side of the cabinet.
As you can see, this box is pretty full and there's not much room for additional equipment.
Now Ron is working on the front side of the cabinet while David AE6W looks on. John, N6XN (with the laptop) is checking the internet connection.
Ron checks levels with the service monitor while David watches.
Here's a photo of the back side of the cabinet. Notice the filter cavity sitting on the board: Nature's Insulator. There won't be any of this in the new cabinet.
Nearly everything in here is either modified commercial gear or homebrew. Can you guess what this device does?
Here's the whole busload: (L-R) Ken WB6IVK, Rich KO6FR, Ron W6BIS, John N6XN, David AE6W, Bill KI6GPN
Now that you've seen where the 441.800 signal has been coming from since 2000, have a look at the new facility. These shots were taken by Ken at W6BIS in his outdoor workshop. This is the new backside. The equipment includes repeater transmitters and receivers for 441.800, 440.050 (DStar), 147.180, APRS, transmit and receive link equipment and 802.11a/g (wifi). The filter cavities are mounted on the side walls. (no more wood)
And finally, here's a photo of the front of the cabinet. Pay attention because the upcoming contest is going to ask a question about this shot. (There are nearly a dozen fans in here but that's not the question)
The WiFi
An integral part of the project is the inclusion of 802.11a/g. The 802.11a is 5.8 gHz and will carry audio links between the control point and the mountain top. It and the 802.11g will carry internet access as well as gateway data for the DStar system. Here are some photos of the antennas for that equipment.
5.8 gHz radio/antenna 1 This is a 5.8 gHz transceiver built into the back of a shallow dish antenna. Notice the signal strength LEDs, this shot shows 2 of 4 lit.
5.8 gHz radio/antenna 2 Same shot with the lens drawn back to show the location on the tower.
The "WiFi center" The gray box above and to the right of the yagi houses the 2.4 gHz equipment and the vertical antenna provides the RF link to the control point.
Leftovers
Photos also by Ken but too good to toss. Captions not provided.
Installation Continues: April 5th
The Installation Crew: Ron, W6 BIS; Greg, KI6JTR; Gary, KG6WKM; John, N6XN.
The cabinet is loaded on a pallet in the back of John's truck.
It took longer to tie it down than to load it. Here john is adding a couple more ropes at Ron's suggestion. Good thing too, they took a beating on the dirt road!
Gary has the battery cabinet loaded and is getting ready to haul the emergency power equipment.
John and Gary putting the batteries into the cabinet for transport.
These are 100 Amp/Hour 12 Volt units.
The crew arrives on the hill and begins removing equipment from the old cabinet. Some of it will be reused. L/R Greg, Ron,Gary.
Here Ron demonstrates one of the reasons the old cabinet was replaced. It was so narrow that in several places the mounting flanges had to be cut away to make room for the equipment.
The old emergency power system consisted on two 12Volt batteries. Here John and Gary are stripping the old "vault".
The repeater power system uses an isolation transformer to protect it and the source from lightning. There is no metallic connection between the repeater and the power company equipment. Here, Greg disconnecting the transformer so it can be moved.
The feedlines have been disconnected and are tied back out of the way during the installation.
The isolation transformer must be moved around to the front of the tower to make room for the battery cabinet.
The pad is now clear and ready for the new cabinets. The thought that was running through John's mind was Rich's comment: "If you drop it, it will go all the way down the hill." No kidding; we would have had to go back to Napa to pick up the pieces!
Unloading 1 Unloading 2 Unloading 3 Unloading 4 Unloading 5
Unloading 6 Unloading 7 Unloading 8
Safely on the pad and ready to rotate into position
Safely on the pad and ready to rotate into position
Rotating the cabinet into place
Checking for fit. The gray object just above the transformer is the generator inlet. If it looks like a commercial power outage will last longer than the batteries can sustain, a generator will be plugged in here. There is an automatic transfer switch built into the cabinet.
The final adjustments 1 The final adjustments 2
Attaching unistrut to the cabinet. This is how the equipment is secured to the tower so that it stays put during an earthquake.
Earthquake bracing 1 Earthquake bracing 2
Ron, Gary and Greg begin re-installing the equipment.
Greg and Ron begin rewiring the transformer.
Ron, Gary and Greg installing the battery cabinet. Did they set it on someone's foot?
Greg terminates the electrical inside while John installs the battery strings.
One of the many terminal strips
Greg tests his work while John finishes up the battery wiring.
Detail of the wiring: A) Main feed from the PG&E. B) Wiring from the isolation transformer to the main cabinet power supplies. C) Wiring from the battery breaker panel to the transfer switch.
Here's the contest question. The person guessing the number closest to the correct answer, without going over, wins the dual band radio. Question: "During a power failure, with all of the equipment in the repeater cabinet operating, what will be the maximum current flow, in DC Amps, flowing in conduit C)?" Send your answer to The Editor. Be sure to include your name, callsign and email address.
Greg drills a hole for the internet cables. Yes, this is where the internet comes from. Who knew?
Now it's time to re-connect the feed lines, but first they need to be sorted out. The coax, hard lines and power and cat-5 cables are all braided together.
The feed lines 1 The feed lines 2 The feed lines 3 The feed lines 4
Installing a mast clamp. The new extension mast had a bit of slack in it. In this shot John is installing a clamp to keep things from rattling.
Closing Up. Still some work to do: Installing the D-Star radio and re-terminating the feedlines. Each coax will need to be dressed and shortened up. Real grunt work but necessary. It will keep for another day.
Quitting time 1 Quitting time 2
Additional WiFi details.The W6CO-1 network is nearly complete. On April 17th the 2.4 gHz radio was switched from the 10 dBi internal antenna to the 15 dBi omni. Signal strength between the tower and the temporary control point increased significantly. We now have a mesh network between Napa and the repeater site.
The wifi hardware (1) See photo 2 for details.
The wifi hardware (2) A is the 15dBi Omni. B is the 2.4 gHz "NanoStation" and C is the 5.8 gHz PowerStation. The path between the tower and the internet connection is just under 6 miles. Power for both radios is 26 dBm. (400 mW).
The next step will be to install the D-Star computer at the repeater site and connect the 5.8 gHz radio to it. This will provide gateway access for the D-Star system which is about to be installed. More details later.
Here are a couple of details of the DStar computer. This is a modified AMD Athlon 3200 running 1 Gb and 12 Gig storage. Aside from two NIC cards that's pretty much it. CentOS has been installed on the HDD to support the Icom software and a couple of other nifty hardware features have been installed.
First and major mod: The power supply has been removed and relegated to the junk box. It has been replaced by a 200 Watt MiniBox power supply (marked "C")so that the computer has no need for 120 VAC. It runs off the cabinet 12VDC supply just like everything else. The MiniBox is shown just below the HDD (marked "B") See Photo 3
The other item is an Uddle Systems DTMF decoder board which will give us remote access to the computer and several other devices at the repeater site. DTMF audio is piped into the computer to the Uddle board where a combination of relay contacts or common collector "closures" can be selected by a radio signal. This board is just above the HDD (marked "A")
The eight closures are cabled out to the 8-position barrier strip mounted to the side of the 3-1/2" cage.
