X-Band Repeater and APRS Digipeater Workshop/Field Exercise

[K7DCL]

Cross-band Repeater and APRS Digipeater workshop/field exercise.

Current Status will always be in this post.

This is a workshop/field exercise that will setup and operate a cross-band repeater and an APRS digipeater to communicate with mobile units in canyons that have no established repeater coverage and no established APRS digipeater coverage.

General exercise location(s): 4 Peaks Rolls area.

Here is a printable writeup:

428

Here is a printable Topo Map:

357

Here is a gpx file with waypoints:

358

Staging time and location:

8:00am Sunday August 1, 2010 (arrive 15 - 20 early if you plan to eat.)
Denny’s (inside)
17053 E Shea Blvd (@Saguaro Blvd)
Fountain Hills

Frequency Plan:

x-band 1 (power boost) TX: 146.920 (-) pl 162.2 RX: 441.025 pl 233.6
x-band 2 (full x-band) 147.550 : 446.500
command channel 446.050
event simplex 147.520

If your radio supports APRS message groups then add 4X4HAM


What we need to conduct this field exercise:

Base Station(s):

At least one base station with internet access, the ability to track APRS beacons and access to either Shaw Buttes and/or Mt Ord repeaters. Operator will verify that our APRS digipeaters are in the packet path. Software Topo map capability is a plus.

Repeater Station(s):

At least one mobile unit capable of providing a cross-band repeater function.
At least one mobile unit capable of providing an APRS digipeater function.
In addition to the cross-band and digipeater functions the Repeater Station(s) must be able to communicate on both VHF and UHF at the same time.
(The above three may be provided by one mobile unit only if it is capable of providing all three functions at the same time.)
Portable antennas may be useful.

Vehicle requirements: 2 wheel drive is OK.

Canyon Stations:

At least one mobile unit with APRS beaconing capability and VHF and/or UHF voice at the same time.
At least one companion mobile unit with VHF and/or UHF for safety.
3.0-3.5 trail
What are your capabilities?

Capability -- yes/no
4x4 (3.0-3.5 trail)
2m
70cm
x-band
GPS
APRS
APRS digipeater (radio model)
Base Station

[AD5VG]

4x4 (3.0-3.5 trail) - Y
2m - Y
70cm - Y
x-band - Y
GPS - Y
APRS - Y
APRS digipeater - Y (as soon as I learn how to set it up)
Base Station - Y

I could do this depending on the date, either on the base station side or in my Jeep out in the field.

[KE7GRM]

Capability -- yes/no
4x4 (3.0-3.5 trail) Yes
2m Yes
70cm Yes
x-band Yes
GPS Yes
APRS Yes
APRS digipeater No
Base Station No

[N7IYT]

Count me in, I have a new FTM-350 with APRS installed in the Jeep.

4x4 (3.0-3.5 trail) Y
2m Y
70cm Y
x-band Y
GPS Y
APRS Y
APRS digipeater N
Base Station Y
Radio Make/Model: Yaesu FTM-350R, Yaesu VX-8R
SSIDs -7, -9

[KD7WCD]

Sounds like fun. If I am in town and the timing is good I'll be there.

Capability -- yes/no
4x4 (3.0-3.5 trail) - Yes
2m - Yes
70cm - Yes
x-band - Not any More :(
GPS - Yes
APRS - Yes
APRS digipeater
Base Station - Yes (Can be portable)

[KE7KUS]

Capability -- yes/no
4x4 (3.0-3.5 trail): Yes
2m: Yes
70cm: Yes
x-band: Yes
GPS: Yes
APRS: Yes
APRS digipeater: Yes
Base Station : Yes

I've got a D710 in the truck (XBand or Digipeat) and can add in an additional DR-135T w/ a Tracker2 installed if needed as an additional digipeater. I've got a couple of HT's and a 900MHz rig that I can throw in there too, if needed. Base station is setup, although I'm only on APRS via -IS, not -RF. I could probably switch it up with enough advanced notice. Sounds like a great exercise, and might be useful to work as a joint op with the MCECG folks as practice for SAR, or other emergency service.

[KC0NNT]

Capability -- yes/no
4x4 (3.0-3.5 trail) Y
2m Y
70cm Y
x-band Y
GPS Y
APRS Y
APRS digipeater Y via D700
Base Station Y
KC0NNT-9

I would love to be involved. Thank you.

[K7DCL]

Here is an excellent post on APRS messaging. Kurt KE7KUS has provided a basis for a standard for our APRS messaging.

http://www.4x4ham.com/showthread.php?152-APRS-Messaging&p=740

APRS messaging groups and bulletins will be added to the workshop and field exerise.

Thanks, Kurt KE7KUS for the input.

[N7IYT]

A couple of thoughts on this exercise:
1. We need to be sure that the stations that participate in the exercise can reprogram their radios in the field. Depending on what we find during this exercise, we may have to make changes and try several configurations. Once we find the ideal configuration, we should post the configuration files on the website and the stations participating in the Samdog run should load that configuration into their radios before the event.
2. From what I have read (this is not first-hand knowledge) the path settings could make or break this event. The suggested settings for urban environments is Wide 1-1, Wide 2-1, this may not be appropiate for our purpose and may cause too many packets to be sent. From what I have read, a a shorter path may be better for our purpose, we will have to determine this during the exercise.
My recomendation is that we have somebody with the ability to reprogram the radios used in this excerise, preferably with a laptop computer, so that all stations are setup in a compatible manner. This thead asks for information about the capabilities of the stations involved, we should add radio make and model to that list of qualifications and make sure we have somebody involved who can make a configuration file for each radio represented. I will be using a Yaesu FTM-350 and a Yaesu VX-8R for the exercise and the Samdog run. And I have a laptop, software, and cables to program both of these radios with a standard configuration file. I suspect that most the the APRS capable radios involved in this exercise and event will be Kenwood radios, so I hope somebody will be prepared to make a configuration file suitaible for Kenwood radios.

[K7DCL]

Richard N7IYT makes some good points in post #9. Please program your radios before the event and know how to change the configuration in the field. Bring your radio manual. Also edit your post to add radio type for the digipeater.

The date will be Sunday, August 1, 2010, see post #1.

[N7IYT]

David,
will your Communications plan be developed enough before August 1st that you will have a list of Simplex and Repeater frequencies that we can program into the radios at the same time? This is especially important if a cross-band repeater is part of the plan.
In another thread on this site, Kurt, KE7KUS, suggested adding 4X4HAM as a message group. I think this is a good idea and I have added it to my radios. I suggest a separate message group for this event called "SAMDOG" that way we can target our messages to stations involved in the event, and still have the option to send a message to 4X4HAM if the situation warrants it.
The next item may not apply to this event, but may be of interest. This morning I discovered how to send a text message to a cell phone from APRS. This could be very valuable during recovery operations and other off road activities. I would be happy to share this information with anybody who is interested.

[K7DCL]

Thanks for the input Richard.



David, will your Communications plan be developed enough before August 1st that you will have a list of Simplex and Repeater frequencies that we can program into the radios at the same time? This is especially important if a cross-band repeater is part of the plan.

I'm working on the simplex and repeater frequencies now, should be able to add those to the first post today or tomorrow.



In another thread on this site, Kurt, KE7KUS, suggested adding 4X4HAM as a message group. I think this is a good idea and I have added it to my radios. I suggest a separate message group for this event called "SAMDOG" that way we can target our messages to stations involved in the event, and still have the option to send a message to 4X4HAM if the situation warrants it.


I'll also add this to the first post.



The next item may not apply to this event, but may be of interest. This morning I discovered how to send a text message to a cell phone from APRS. This could be very valuable during recovery operations and other off road activities. I would be happy to share this information with anybody who is interested.

Is that via the email message function?

[N7IYT]

[QUOTE=K7DCL;777

Is that via the email message function?[/QUOTE]

Yes, the various cell phone providers have made provisions to send a text message to their phones via e-mail. APRS can send a message to an e-mail address, which means it can send a text message as well. It seems that text messages are the best way to contact my children, so I see a lot of value in this. There are places out on the trail with no cell phone service, and only a few of our repeaters have phone patches, so I see a definate value being able to send text messages to cell phones.

[AD5VG]

Well after reviewing the updated first post I'll most likely be skipping this event. I finish a 12hr shift at 0530 that morning and really don't feel like fumbling around in the desert in a sleep-deprived state (even if it could lead to more practice than was originally intended). Have fun out there guys, if I get a chance I'll monitor from my house for a bit.

[K7DCL]

OK Kevin, I fully understand thanks for the update.

[KE7KUS]

I had a few thoughts after re-reading this thread tonight:

1) Richard's concern with packet density on the local APRS channel may be valid for a run the size of SAMDOG. One or two mobiles in a test session is one thing, but 50 mobiles added to the channel in the local area is a significant increase in packet density on an already busy network. I saw two ways around this -

A) Run the event on a frequency different than the national APRS channel (144.39). This technique is often used by SAR teams, and in cases like race support to prevent clogging the national channel, while allowing relatively high fidelity packet info to propagate for support of these types of events. I would suggest running the event on the alternate APRS input of 144.99. You would then have to create a chain of 144.99 digipeaters back to a base station monitoring 144.99 and also connected to APRS-IS as an I-Gate if you wanted the info to make it into APRS-IS. The end result is that everyone's data would be relayed onto the internet to allow anyone to see the data, just as if it got in through a normal I-Gate; however, the data would probably be much higher fidelity than normal due to the lack of congestion (packet collisions) gained by using the alternate channel. This solution would also allow anyone who was planning on being on 2m APRS for the event to participate. They probably wouldn't even need to change their APRS path settings if they are configured to run the New-N Paradigm standard WIDE1-1,WIDE2-1, as long as we site and configure the chain digipeater stations properly.

B) The second option is to run the event using the alternate frequency method recommended above in conjunction with the already established UHF APRS network on 445.925 that covers most of central AZ. Currently there are UHF digipeaters on White Tanks, Ord, Shaw Butte, and at least two UHF I-Gates in the Phoenix metro area to pass packets to the internet. The packet density on UHF APRS is very low, even in Phoenix which means lots of free room to transmit. If we could set up a crossband repeater on 144.99 and crossband over to 445.925, we could eliminate the chain of digis back to a base-station I-Gate on an alternate channel and just get everything into APRS-IS by using the UHF I-Gates. Coverage from Ord and White Tanks should easily get most of the area we're looking at, I'd guess. We could just work UHF APRS without the crossband, but I'm guessing that would exclude a lot of guys on the trail from participating on the APRS network, since many of them can only run APRS on 2m.

Obviously this adds a minimal level of increased complexity to the APRS side of the event; however, it shouldn't require any additional equipment to execute either option, just a few extra people to execute option A. I think a lot of existing APRS users would be surprised at how effective APRS can be on a non-saturated channel, and I think that's the kind of fidelity you're looking for on something like the SAMDOG run, especially if you need info to coordinate recovery efforts.

Kurt
KE7KUS

[K7DCL]

Kurt,

Thanks for the comment.

I think your alternatives are interesting and warrant further discussion.

Even though there may be 50 – 60 jeeps on the Samdog run only about 8 or so will be 4x4 Ham units with APRS beacons. So the traffic is significantly less than you may have been expecting.

Alternative (A) would also need x-band repeater I believe. Also it assumes what we would have a resource with the proper equipment and a functioning I-Gate that would be in range of the x-band location and an additional x-band unit in the field.

Alternative (B) is more attractive because it is basically the same as using 144.390 but on the less congested UHF APRS freq.

The big problem is getting the resources that have the configurations that are needed signed up for the event, so I’m not eager to increase the resource requirement to a level beyond what the event needs.

Don’t get me wrong I believe that all the various capabilities that we can develop and train on are good.

David

[K7DCL]

Bump.

Still need a base station to monitor the APRS beacons/paths during the field exercise.

[KC0NNT]

Tell me what you need.

[N7IYT]

David,
I have a few questions about your PDF file for the communications exercise:
1. For x-band 2, the full crossband mode, do you intend for the crossband repeater to transmit on the VHF side or the UHF side?
2. Do you plan to use a PL tone for the cross band repeater? If so, which one?
3. You asked the base stations to track several callsigns, but you did not include any SSIDs. Would you like us to run without an SSID for this excerise? Or should we supply you with the SSIDs we normally use in the radios we plan to use for this event? In my case, I will use N7IYT-9 and possibly N7IYT-7.

Thank you for putting this plan together.

[K7DCL]

I'll respond inline.


David,
I have a few questions about your PDF file for the communications exercise:
1. For x-band 2, the full crossband mode, do you intend for the crossband repeater to transmit on the VHF side or the UHF side?
Both sides full crossband test.
2. Do you plan to use a PL tone for the cross band repeater? If so, which one?
I had not planned on it but I am wide open to recommendations.
3. You asked the base stations to track several callsigns, but you did not include any SSIDs. Would you like us to run without an SSID for this excerise? Or should we supply you with the SSIDs we normally use in the radios we plan to use for this event? In my case, I will use N7IYT-9 and possibly N7IYT-7.
You are right, I will add that to the requested information (will add -7 & -9 for you).

Thank you for putting this plan together.

[K7DCL]

Please update your information/capabilities post to include the ssid you will be using.

Thanks,

David

[K7DCL]

Tell me what you need.

I need a base station as defined in the first post. Not you Randy I need you in the field.

If the roles in the first post are not clear please tell me!

[N7IYT]

David,
I added this event and the Samdog Run to the calendar.

[K7DCL]

First post has been updated, new attachments.

[K7VZ]

I could maybe run base? Let me know where I can best serve.

4x4 (3.0-3.5 trail) Y
2m Y
70cm Y
x-band Y
GPS Y
APRS Y
APRS digipeater (radio model) N
Base Station Y

[KE7KUS]

Unfortunately, I'll be unable to participate on Sunday morning, August 1st. I could possibly man the base station after 12:00pm or so, but I'm unavailable in the morning.

[AD7TI]

If you still need a base station, I can fill that role. The only thing I don't have readily available that you mentioned in the first post are local topo maps on my PC. If it is on the internet I can access it. But no Google Earth, my video card is not compatible. - Tom

[K7DCL]

Unfortunately, I'll be unable to participate on Sunday morning, August 1st. I could possibly man the base station after 12:00pm or so, but I'm unavailable in the morning.

Kurt,

Sorry to hear that you won't be able to make it.

David

[K7DCL]

If you still need a base station, I can fill that role. The only thing I don't have readily available that you mentioned in the first post are local topo maps on my PC. If it is on the internet I can access it. But no Google Earth, my video card is not compatible. - Tom

Tom,

As long as you can look at the APRS beacon paths to identify our digipeaters you will be fine. The topos were a nice to have but not a requirement. I'll put you down as the base station. More infomation to come as to how we will pass traffic. Expect 9 - 9:30 to about 1pm.

Thanks,

David

[K7DCL]

I could maybe run base? Let me know where I can best serve.

Virgil,

I think putting you on top of the jeep jam net control hill will be a good spot. That will also free up some moving of resources between different locations.

I will add you to the plan and rework it over the weekend.

Thanks,

David

[K7DCL]

All 3 attachments in the 1st post have been updated.

[AD5VG]

If you still need a base station, I can fill that role. The only thing I don't have readily available that you mentioned in the first post are local topo maps on my PC. If it is on the internet I can access it. But no Google Earth, my video card is not compatible. - Tom


Tom,

As long as you can look at the APRS beacon paths to identify our digipeaters you will be fine. The topos were a nice to have but not a requirement. I'll put you down as the base station. More infomation to come as to how we will pass traffic. Expect 9 - 9:30 to about 1pm.

Thanks,

David
Tom, if you use www.aprs.fi to display the APRS info you can get a rough topo display as well. In the upper right corner of the main map display there is a button labeled 'Map'. Click on it and a drop-down appears with options, at the bottom of the short list is 'Terrain'. Select that and when you zoom in all the way you will see a topo overlay with a 40' contour interval; backing out one or two steps gets you an 80' interval. Zooming out any further will just show shaded terrain with no contours.

[K7VZ]

I'm K7VZ-9 from the Jeep and K7VZ-10 from my phone. I plan to run both tomorrow to compare coverage side by side.

[KC0NNT]

Great exercise today David! I learned alot and I learned that I need to learn some more.
Great seeing everyone again. And Tom thanks for your help as base. You stayed awake the whole time!

[K7DCL]

Thanks to all that participated in the field exercise, I think we all learned something. Tom thanks for standing by for so long, it is much appreciated.

David

[AD7TI]

I missed my post lunch afternoon nap on Sunday but managed to pull through. - Tom

[K7DCL]

I missed my post lunch afternoon nap on Sunday but managed to pull through. - Tom

I resemble that remark!