CAVERN’s preprogrammed Retevis RT 22 radios channels match the way most FRS/GMRS radios are programmed, but only for the first few channels. This is because the RT22 only has 16 channels and cannot transmit at the legally required 0.5 Watts for FRS channels 8-14 (so we left those out for now).
What this means in practical terms is that on CAVERN pre–programmed FRS radios (e.g. the “Retevis RT22”), Channels 1-7 correspond to most off-the-shelf FRS radios, HOWEVER: CAVERN’s Channels 8-16 are NOT programmed to the standard frequencies and tones.
This table below shows: pre-programmed CAVERN channel locations (in the first column); the corresponding normal “Standard” FRS and GMRS channel location for most non-CAVERN radios (i.e. the “factory settings”) and; additional CAVERN frequency & tone settings for radios (i.e. to help limit Main Repeater access to Cobb Area volunteers):
Not everyone wants to listen to a scanner or CAVERN throughout the day…and especially at night. Luckily CAVERN programmed radios can screen out the day–to-day chitchat on the frequency, so that you only hear alerts of local emergencies put out by fellow CAVERN volunteers.
To screen out chitchat set your CAVERN-programmed RETEVIS RT22 to channel 9, or (newer) BTECH GMRS V1 to channel 33. Additionally any FRS/GMRS radio that supports privacy tones can be set to the standard channel 15 with a “privacy tone” or CTCSS receive tone of 103.5 Hz. (Often tone #13 corresponds to 103.5 Hz.) Consult your radio’s manual or send email to Net Control.
NOTE: We test the Emergency Alert channel tone at the beginning of our check-ins or when a Fire siren is tested. But we conduct the actual check-in roll calls on our non-emergency channels! (RT22 Ch 8, GMRS V1 Ch 15 or 23, most FRS/GMRS radio ch.15 with NO privacy tone.) If you modify your radio to hear the Emergency tome, be sure to reset your radio to the regular channel after test or you may not hear anything else!
Should you need to announce an emergency, first listen and ask on the non-emergency channel if the network is already aware of the emergency.
If there is imminent danger to the some part of the Cobb area (as in a moving fire within 1-3 miles likely to require evacuation) put out an emergency alert with as much detail RETEVIS RT22 to Ch 9, or BTECH GMRS V1 to Ch 15 or 23 with CTCSS 103.5 set on transmit. Additionally any FRS/GMRS radio that supports privacy tones can be set to channel 15 with a “privacy” or CTCSS tone corresponding to 103.5 Hz (often named tone #13).
Anyone local to the Cobb Area who can hear the CAVERN radio network is welcome to check in. Our main Repeater is atop Hobergs Hill (overlooking the resort destroyed in the 2015 Valley Fire). The frequency is 462.550 Megahertz with a DCS tone of D071N.
It’s OK to be pseudonymous, but show up! You do NOT need a fancy guv’mint ‘Callsign’ or even one of the group-based CAVERN_IDs we issue. (At least not the first couple of times). You can join everyone by checking in with just your first name or even a “handle” (i.e. a nickname or nym). You will eventually receive a CAVERN_ID: use that for your own convenience and so we can find you in case of an emergency during which you urgently need assistance.
NOTE: “CAVERN” is a local network for the areas around the town of Cobb and Cobb Mountain, if you’re wondering why it’s the Cobb Area Volunteer Emergency Radio Network (thus: “CAVERN“). FYI, the nonprofit CryptoRights Foundation (CRF) is using constructive feedback from the World to create a knowledgebase of information for a generic Volunteer Emergency Radio Network website. That website will be a free resource (e.g. downloadable freeware) that any group or community can use to build it’s own VERN so everyone within range can communicate in emergencies that suddenly knock out other media. To support this research and development into public use of public airwaves for public safety, CRF plans to offer project merchandise, crowdfunding opportunities and commercial licenses: proceeds will benefit contributors to this important public benefit work. Please send small tax-deductible donations (stapled to really large ones? 😉 ) using the ‘Donate‘ info in the sidebar to support this volunteer-driven nonprofit digital human rights R&D. Thank You!
We begin each weekly Check-In by testing our Emergency Alert channel. We do this, a few minutes before the main check-in starts, to make sure everyone is able to tune their radios to hear emergency alerts ONLY (if people want to, they can use the Emergency Alert channel to ignore daily patter on our main channel). Once we’ve given everyone a few minutes to confirm their ability to hear the Emergency Alert Channel (see the right-hand sidebar: we generally program these channels into peoples’ radios for them), we then proceed with the main Check-in, which is a roll call led byaNetwork Control person and organized by CAVERN groups in order*.
* We check in our Cobb Area Volunteer Emergency Radio Network operators starting from Group 1 through Group 6 and even to ‘Beyond’ the local area. Radio waves can propagate over very long distances. We have spoken to radio operators as far away as Signal Peak in the Sierra Nevada mountains. That’s 120+ miles east, using just a 5-Watt GMRS radio (and direct line-of-sight)!
The CAVERN Directed Net
CAVERN is aDirected Network, meaning that, while any network session is in operation (usually for less than an hour), all communications are routed by a person who serves as “Network Control” (aka “NetCon“). Whoever is NetCon during the network session, that’s the person running the network, queueing people up in an orderly way so they don’t ‘step on’ each others’ transmissions (see Note #1). Basically, you don’t transmit until given the go-ahead, and if you need to interject anything, you first ask for permission as briefly as possible. To ask NetCon for permission to speak next, you use short phrases such as: “net control <your first name>” or “net control, comment…”. When NetCon says to go ahead, then you proceed with your “traffic” (i.e. transmission or communication).
To learn how we use the Directed Network protocol, which is very practical in emergency situations, see: “Intro to Network Control“.
NOTES: 1. Leave breathing room on the Airwaves: after anyone speaks, everyone should allow a few beats so NetCon can queue the next speaker. Sometimes, it’s so someone can answer your question (other than NetCon). 2. In the world of FCC-licensed GMRS radio operators (which is a different world from the unlicensed Citizen’s Band radio, or “CB”, familiar to fans of the Smokey & The Bandit movies), we reserve the word “break” ONLY for extreme emergencies. You will probably never say “break” on the CAVERN network: if anyone does, it’s probably bad news for everyone (e.g. a wildfire or storm damage). 3.Comments (i.e. non-roll-call messages) should benefit all listeners on the network. 4.We make time for casual chats among members after we close the net and release the frequency for general traffic.
CAVERN Check-In Protocol
Check-Ins start with Group 1 (download the sample check-in script at the ‘Intro to Net Control‘ link in Note #1 above). When you hear NetCon call for your Group by its number: first listen for the Licensed GMRS radio operators in your group to check in (they often have a lower number and can hear more people with their higher-powered radios); then check in by the order of your CAVERN ID. If you’re #5 in your group, you’ll go, and #6 checks in after you, etc.
Say your first name plus your CAVERN ID (or GMRS callsign, if you have one) to check in. That’s really all there is to it! For example: “Betty at Seigler 87, checking in” or “Angelo, LMNO123, checking in”. If you don’t know your CAVERN ID or don’t have one yet, no problem: just use your first name or a “handle” (a nickname, like “Pink Panther”). We understand that some shy woodland creatures may want to remain pseudonymous or that some parents prefer their kids not to use their real names: that’s perfectly OK. The important thing is to use a persistent pseudonym to identify yourself so others can reach out to you reliably in an emergency.
If at first you do not succeed by immediately hearing acknowledgement from NetCon, just try checking in again. You can even check in later during another group’s time (anyone from the first few groups can check in late during any group’s slot or at the end).
You can also ask someone who you can hear and you can probably heat NetCon to “relay” your check-in for you. If you can hear a weak signal/distant station that NetCon does not seem to hear, during a gap you can say “net control, relay…” and, as soon as NetCon gives you the go-ahead, pass on the info you heard. (Expert Tip: listen with your radio’s “squelch” off, or very low, to hear weak stations.)
If you have a question during a check-in, just say “net control, question” and ask it when your turn comes (e.g. “how do I turn my squelch down?”). If it’s urgent, just say so. For more detailed questions, please send Network Control an email.
How To Relay Check Ins
Sometimes, people who are clearly audible to you cannot be heard by Network Control. In those cases, you can be the “relay” between them and the other people on CAVERN’s network. In fact, in a serious emergency, the ability to relay for neighbors can be a potential lifesaver for you or those near you. Happily, there’s an easy protocol for relaying signals. Here’s what a very quick, efficient relay can sound like:
Hannah 1: “NetCon, Relay…” Net Control: “Hannah 1, go with your relay, Brett…” Hannah 1: “Relay for Hannah 22, Margaret. That’s Margaret at Hannah 22.” Net Control: “Copy, Brett. Margaret at Hannah 22 is checked in…”
How NOT to Check In
Hannah 13:“Achey-breaker-break. This is Hannah 13 aka Josh the Radio Dude, aka Whiskey Tangle Foxtail Doohickey 7-4 Niner. I’m hearing someone out there, but it’s pretty weak… might be Brenda, or Bob, or maybe Billy? I dunno… hey, I really like the new website, you guys! Anyway, go ahead and check in my dog Jasper, my pet iguana Tickles, my cockateel Snorton Buffalo Wings III… oh, and me, Josh the Radio Dude… (Awe-sooome!) ‘Kay… I’m gonna go have some lunch now. Well, this has been amazing fun for me, as usual. Back to you, Mr Networky Dude.” Net Control: “Uh… Josh, your super-long transmission stepped on Brett’s urgent relay. Josh, hold your traffic until you are prompted for your turn by NetCon and please try not to exceed the transmission limit or you’ll send everyone in the network another high-pitched overtime alarm tone. Brett, please repeat your relay… go ahead, Brett…”
In the “not” example above, try replacing the word “relay” with the phrase “urgent wildfire alert!”. Can you understand why worried people under the imminent threat of a wildfire would not be that interested in your pets’ names or your lunch plans? Would your otherwise “awesome” sense of humor be appropriate in such a situation? Maybe you see why rehearsing network protocol is important…? Remember: we’re practicing for life-and-death situations that are guaranteed to happen someday. We all need to be ready to communicate what we know (or need to know) in the most professional way possible, especially when talking to emergency responders. Be like “Brett/Hannah 1” below. Short & Sweet!