SJC EMCOMM Freqs
SJC1 - 147.210 + 114.8 Stockton (Stockton Pri)
SJC2 - 146.655 - 100.0 Tracy (County Pri)
SJC3 - 145.210 - 100.0 Tracy (County B/up)
SJC4 - 147.090 + 114.8 Lodi (North Pri)
SJC5 - 146.985 - 100.0 Manteca
SJC6 - 147.165 + 107.2 SDARC
SJC7 - 147.015 + 114.8 Copperopolis
SJC8 - 147.105 + 94.8 Stockton
SJC9 - 146.895 - 114.8 Mt. Oso - Disabled
SJC10 - 444.400 + 114.8 Copperopolis
SJC11 - 444.325 + 94.8 Stockton (Stockton Pri)
SJC12 - 443.825 + 107.2 Mt. Oso
SJC13 - 444.575 + 107.2 Stockton
SJC14 - 444.850 + 114.8 127.3 Tracy 
SJC15 - 444.500 + 114.8 Stockton
LLNL - 146.775 - 100.0 Livermore


TAC1 - 146.550

TAC3 - 146.535
TAC4 - 146.430
TAC6 - 156.565
TAC7 - 146.595
TAC8 - 146.445
All simplex
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N5FDL/CEVOL Repeaters

Stockton: 147.210 + N5FDL and 444.500 + K6TRK Both PL 114.8 (linked)

Copperopolis/Gopher Ridge: 147.015 + and 444.400 +  (not linked) N6GKJ 

Mt. Oso: 146.895 - N5FDL and 443.825 + PL 107.2 (not linked)

Tracy: 444.850 + KB6EMK PL 127.3

Affiliated Repeaters

Bear Mtn.: 146.090 + and 444.250 + WB6ASU Both PL 114.8 (linked)

Mt. Delux: 145.210 - PL 100.0 WA6SEK (10mi S of Tracy)

All repeaters are open to all users.

Tuesday
Aug122008

Putting P25 Scanner Audio on the Net

Recently, my local PD went to P25 digital radios, meaning lots of people were surprised when their scanners suddenly went dead, if they were lucky enough to have a PL tone programmed. People using older/less expensive scanners found themselves listening to the nasty roar of the digital data stream.

One of the surprised former listeners was my wife and another was her partner, together the staff AMR Medic 90 in our town. Some of the other crews were surprised, too, when their handheld scanners also stopped hearing the cops. (I get the idea that the PD didn't tell allied agencies what they were planning to do).

My wife had been using a commercial Kenwood talkie that I'd programmed the UHF police frequencies into. She'd often have it on while working, sometimes giving her a 2-minute lead on an incident her rig would eventually be dispatched on.

(Two minutes can be the amount of time from when the cop says, "Send us a medic unit" until the call is actually toned-out to the rig. It really can take two minutes, which I remember from CPR class, can result in a 20 percent lesser liklihood of survival for a patient in cardiac arrest.)

Having a radio also let them know when a scene had been secured by the police and they were clear to enter. Another two minutes saved.

I've thought about purchasing a P25 UHF radio for my wife, though the $1,300 price tag stands in the way at present. My other option is a $500 P25 scanner, which is probably not rugged enough for daily use by an ambulance crew. The scanner is also hard to operate, at least compared to a channelized commerical radio. Turn the radio, pick the channel, and you're done.

As I said, It's sad I can't get my wife a commercial P25 talkie.

However, my wife's partner has a data card for her laptop PC which may provide the answer: Maybe I can send scanner audio over the Internet and they can listen to the cops that way? That has to be cheaper than a P25 radio, doesn't it?

Only kinda.

I already own a GRE PSR-500 P25-capable handheld scanner radio. But, I don't want to devote it to feeding audio to my Mac desktop and the world beyond. I am planning to write a long piece about this radio, but suffice to say that the longer I've used it, the less I've come to like it.

The control head of the IC-R2500I do, however, also own an $800 Icom IC-R2500 "black box" dual receiver that I use in my office at home, sometimes with the pretty good Spectrum Manager Windows software from Signal Intelligence.

Receiving P25 on the Icom, however, also requires a $200+ P25 decoder board, easily installed into the radio. I've been pleasantly surprised at the quality of the recovered audio.

What I decided to do was take audio from one of the dual receivers in the R2500 and feed it into my desktop Mac and from there onto the Internet, That allows my wife's partner to use her Windows notebook (with the wireless connection when Wi-Fi isn't available) to listen to the audio from the Icom. I am using a $40 program called NiceCast to transmit the audio. It's very easy to use--just install the software, select your audio source, and you're on the air.This shot makes NiceCast look more complex than it really is.

There are Windows programs that do the same thing, though perhaps not as easily. A challenge for any of them will be available bandwidth--carriers usually offer upload speeds that are only a fraction of the download speed. They also often prohibit servers as part of their Terms of Service. You may also have problems if you don't have a fixed IP address, though there are ways around this.

The solution works, including right here in the office, where I listen to the audio feed on my portable as I move from room-to-room during the day. It also works in the ambulance, though it is not perfect solution since it requires the PC to be on all the time.

It's also pretty expensive if you have to buy a radio just for this application. I'd recommend either the Uniden or the GRE P25 models as a less expensive alternative to the Icom black box.

Scanner audio on the Internet is nothing new, but using my Mac and NiceCast made it especially easy. And it's a solution until something better--like the money truck--comes along.

Tuesday
Aug122008

TAC-COMM TRC-1 Tactical Radio Carrier

This isn't so much a review as a "heads up" since I haven't actually purchased what I am writing about. But, the ad in QST looked interesting and led me to something I am planning to recommend to a served agency I am working with.TRC- 1

The TAC-COMM TRC-1 Tactical Radio Carrier ($59.95 and seems a tad expensive) is a metal wrap-around casing into which you mount, using your own bracket or a strap the vendor sells, a radio, power supply, battery, etc., that needs to be made more easily portable.

The carrier is 7.5 inches across, 10.5 inches deep and the height is variable from 2.6 to 4.8 inches, giving the user the option of mounting tall gear or stacking smaller items, such as a mobile FM rig and a packet TNC.

The picture seems to show the product pretty well,  except that you're looking at two TRC-1 mounts stacked one atop the other. The picture also shows the carrying handle and the tilt-bail, which gives the mount a nice upward slant for easy viewing.

On the vendor's web site you can see different sorts of radios and accessories mounted into TRC-1 carriers. These include some photos of radios strapped into the TRC-1 rather than mounted to a bracket inside the carrier.


I'm interested in these right now because I've been asked to design a couple of portable stations for an agency we're working with. Currently, they have a few portable VHF/UHF stations mounted in Pelican cases. The problem is the case doesn't really do anything for how the radio is setup once it's out of the box. The TRC-1 solves that problem and may even negate the need for the expensive Pelican cases. It ought to be possible to drop a couple of TRC-1's into a plastic box of some sort, pad as necessary, toss in some coax, etc., and be done with it.

This looks like a good product, one I am sorry I didn't think about first.

Saturday
Aug092008

How to Develop an ARES Frequency Plan

Wouldn’t it be great if everyone in your ARES/RACES group had his or her radio programmed alike? Then you could count on everyone—even the newcomers—being able to get on a particular repeater or simplex frequency in the hurry.

Net control could tell them to tune to a particular channel number or name, just like the public safety agencies do, rather than announcing a frequency, perhaps repeated two or three times, along with an offset and a PL tone. As a net control, I find names much easier to remember than frequency pairs—even if my radio picks the offset automatically.Save & Close

My ARES group has a large number of inexperienced hams and, frankly, in an emergency the first voice on the 2-meter hospital net is as likely to be an unlicensed nurse as an experienced ham.

In order to standardize the radios and make their operation easier for everyone, I developed a frequency plan for my county’s ARES group. I have recently made it available for adoption by the general ham population.

This document—the San Joaquin County ARES VHF Frequency Plan—includes 58 channels. That may sound like a lot for a county of less than 675,000 residents, but only 15 channels are mission critical. The other channels include 18 regional frequencies and all two-meter simplex frequencies, which add the remaining 25 channels.

The first thing I realized as the project took shape was that nobody wants someone telling him or her what to program into their personal radio equipment. It’s OK for me to program hospital and served agency radios, but I’d like to have this plan loaded into as many radios as possible. Ease of adoption by the amateur community is very important.

For that reason, I took a concept for the state fire department frequency plan and left the first 20 channels open for customization by the user. My channel “load” thus begins on Channel 21. It could just as easily begin on 121, 221, 321, etc., given the large number of memories available in many radios. One of my scanners is programmed this way, with the frequency plan starting on channel 221. As long as the last two digits of the channel number match the plan, I’m happy and the plan remains easy to use.

As for the plan itself, channels 21-35 include three wide-coverage repeaters, designated ARES 1, 2, and 3. These are followed by 146.520, designated CALL. There are five simplex channels, SJS1-5, the initials standing for San Joaquin Simplex. REDX is the designation for 147.420, the informal Red Cross simplex frequency. Local club repeaters round out the group.

These 15 channels cover all the frequencies we are likely to use during a local emergency. I selected them after asking the clubs, talking to served agencies, and finding some quiet simplex channels through computerized monitoring. Each frequency is assigned a channel number and name, never more than five characters in length, a limitation necessary for alphanumeric displays.

ARES1, for example, is the primary ARES repeater for my county. LODI1 is the repeater used by the Lodi Amateur Radio Club. Their simplex channel is designated SJS3 while the Manteca Amateur Radio Club’s repeater is designated MAN1.

The next group, the regional frequencies, uses channels 41-58. Note that I left empty channels between the each of the groups to allow for future expansion. This group was constructed based on a list provided by State OES that includes the frequencies used in surrounding counties.

These were added so that we are ready to offer mutual aid, but also because they provide a link to both San Francisco and the State EOC in Sacramento.

The last group, channels 71 to 95, includes all the 2-meter simplex channels and was added mostly for convenience when doing training exercises. If people are using the channel plan, it’s easy to get newcomers onto the right frequency simply by dialing up the right memory channel. Unlike the other two groups, the simplex channels are not named, so the frequency shows up as the tag the each memory channel.

At some point I will repeat a simplex channel in memory channel 96, changing it with each version of the plan. This will be an easy way to know what release of the plan is in a particular radio.

All simplex frequencies in the plan encode a 100 Hz. PL tone. I am not decoding it, but could do so if needed. It also helps identify radios programmed with our plan. I use tone encode/decode on repeaters, when possible, to reduce interference.

Some people ask why there are no UHF frequencies in the plan. Mostly because of PAVE PAWS, the government RADAR system that has forced big changes in our area’s UHF repeater line-up. But also because, and this may be a good enough reason by itself, new hams could purchase an inexpensive radio.

It turns out the Yaesu VX-170 is a near perfect radio for emergency responders who only need one band. It’s submersible, rugged, easy to use, and the AA-battery pack will fully power its 5-watt transmitter. And it costs about $120.00, which is easy on the new ham’s wallet. If you need UHF, the VX-177 covers that band.

Before wrapping up, here are some things I learned before/during/after drafting the frequency plan.

Before:

1.      Does a plan already exist? – If so, try to make the current plan work or at least use it as a starting point for a new plan.

2.      Are you the right person to create a new plan? – You need at least a constituency and, ideally, an official position (or several) to begin this process. If not, you’re likely to end up with a great plan that nobody uses.

3.      Do your research – Absent an existing plan, what frequencies are being used already? Get lists from clubs and served agencies. I started with a list from California OES for my region.

4.      Don’t expect your plan to take mere weeks to complete. And once it is completed, let it age a little, then go back and make changes before releasing it. Give select friends draft copies of the plan—clearly marked as such.

 

Drafting a plan:

1.      Everything that anyone already uses needs to be included in the plan. Make a list of these frequencies and who uses them. Invite everyone to take part in creating the plan. You need as many endorsers (and eventual users) as possible.

2.      Make sure you have extra simplex channels designated in your plan. Pick a PL and encode it on all your simplex channels.

3.      Don’t make mistakes. At least, don’t make big ones, like the PL tones of your local repeaters or (as I did) including 146.580 as a simplex voice channel when the bandplan places digital users there.

4.      Check coverage to see what can be hit from where. Document this in the plan notes.

5.      Ask for permission. Local repeater owners are key supporters. Establish Memorandums of Understanding with them, if appropriate.

6.      Include version notes, known issues, planned changes, etc. in the “paper” versions of your plan.

7.      Build a plan with the expectation it will last for many years.


Afterward:

1.      Expect to spend forever promoting your plan. Get official endorsement wherever and whenever possible.

2.      Don’t make changes if you can help it. I’d rather add a channel (remember the empty spaces between groups?) than change or remove an existing channel.

3.      Make the available programming files for popular radios. I am starting to do this for a variety of mobile and portable radios. I also keep programming software for popular radios on my laptop and carry cables with me, so I can program radios for people whenever I’m asked to do so.

Obviously, I think it’s useful for ARES/RACES groups to promote a frequency plan such as this. I hope the concepts presented will work for your group and look forward to your comments and questions—so I can make my own plan better.

 

David Coursey, N5FDL , has been licensed for 25 years and is Emergency Coordinator for San Joaquin County (CA) ARES and ACS/RACES Radio Officer for the City of Tracy (CA). He is also a nationally registered EMT, a W5YI senior volunteer examiner, and a mentor/instructor for the ARRL emergency communications courses. He is proud to be 

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