Radio Preppers

General Category => Digital Modes => Topic started by: WA4STO on June 20, 2013, 01:05:16 PM

Title: Building your own digital network
Post by: WA4STO on June 20, 2013, 01:05:16 PM
I've been mentoring (Elmering) some newly-licensed hams (preppers)  who have expressed a need for their own digital networks.

And, not being one to reinvent a particular wheel, I've been pointing them in the direction of a system that already exists, namely WINLINK.

These folks require the following, and I suspect that many of you here will warm up to these requirements.

1.  A network that provides error-corrected data between and among their BOLs and themselves as individuals.

2.  A system that does not require large amounts of RF output, and can be powered by alternative power sources and batteries within the BOLs or at their home locations.

3.  A system that provides enough COMSEC so as to keep nosy neighbors, the media, and the Golden Horde from viewing the transmissions.

WINLINK / WL2K provides all this and much much more.

Here's a very interesting series of FAQs relating to WL2K:   http://www.winlink.org/faq (http://www.winlink.org/faq)  Click on the '100 general questions' link for the really interesting stuff.

More to follow; questions cheerfully answered.

73

Luck, WA4STO
Title: Re: Building your own digital network
Post by: Quietguy on June 20, 2013, 02:27:30 PM
Keep in mind, though, that use of the WL2K system still leaves you at the mercy of outside people to keep their systems up and running.  If an event is big enough to require wide-spread bugging-out it is possibly also big enough to disrupt WL2K access, at least regionally.

It seems to me HF peer-to-peer operation of AirMail or RMSExpress should be considered as a way to avoid depending on anyone else's infrastructure.  WL2K is great for backup email or training purposes, but I see peer-to-peer as the real value for preppers - and, if you can do WL2K, it requires nothing additional other than some prior coordination.

Wally
Title: Building your own digital network
Post by: White Tiger on June 20, 2013, 03:29:10 PM
Very timely and interesting topic - I think this is the way I wish to go - question: I agree that we either need to build-up our WLK2 networks, or we need to find ways to maintain communication without relying on others - if we were to look at something like RMS Express or the other - what additional equipment would be needed?
Title: Re: Building your own digital network
Post by: WA4STO on June 20, 2013, 04:03:10 PM
WT:

Wally is right smack on the money. 

And the answer to your question is that you need absolutely nothing additional, over and above what you would be using for WL2K.

That's because the RMS Express software allows for two kinds of operation:

1.  The 'system' method, which utilizes the international infrastructure which is already in place, and ...

2.  The 'peer to peer' method which allows  WT1 to communicate directly with WT2

In the time that I've been using WL2K I don't think I've ever had to rely on peer to peer connections.  I attribute that to the fact there are so many stations available to relay my traffic, that if one or two are down, no problem, there are plenty of others.

There's another dynamic here that's very important to consider:

While, in any given moment in time, all the relay points might be "up", that doesn't mean that propagation will allow me to connect to all of them.  So what happens to the message that W1ABC sent me yesterday?  Here it is, early morning, I haven't had my first cuppajava yet, and I'm all worried that I might have to find the one station that has the traffic for me.

Never going to happen like that.  The Common Message Servers send W1ABCs message to all (or most, I dunno how that works exactly) the relay points so it matters not which one I actually connect to.  They're all going to have the same exact copy of that message.

Talk about a smart system, done by hams.  Ya just gotta love it.

Getting back to the guys I was Elmering in the previous message.  Two of them have locations that are about five miles apart.  They both have 40 meter antennas which is fabulous for getting into about a dozen relay points.  Less good for peer to peer across that huge five mile expanse.  No problem.  The system itself has copies of the message such that WhiteTigerOne's message for WhiteTigerTwo can be retrieved by connecting to any of the stations in the network. 

I more I use this stuff, the more I like it.

73

WA4STO
Title: Re: Building your own digital network
Post by: gil on June 20, 2013, 04:16:32 PM
After using RMS-Express, I can see how Winlink would be very useful in sending long text documents that would take forever to send with Morse code. You don't even have to pay close attention to the radio while it transmits or receives. You don't even need to be there for that matter! So, I am glad I bout that little SignaLink USB box...

However, Winkink does require a larger radio, and a computer. That means more gear, and more weight. It is mostly a home-based system or camp system if you have some sort of transportation; at the very least, a hand cart. I could add one of those cheap netbooks to my KX3 station.. That would mean a bigger Pelican case, and a bigger solar panel and battery.. It just gets more complicated as soon as you leave the house...

Reminds me Luck, I need to send you a Winlink email for testing and to keep my account open ;-)

Gil.
Title: Re: Building your own digital network
Post by: WA4STO on June 20, 2013, 06:37:01 PM
After using RMS-Express, I can see how Winlink would be very useful in sending long text documents that would take forever to send with Morse code.

. It just gets more complicated as soon as you leave the house...

Reminds me Luck, I need to send you a Winlink email for testing and to keep my account open ;-)

Gil.

Exactly.  And that's why Morse (and voice modes for that matter) are not part of this discussion.  That is, the  people I'm working with have set forth requirements and those requirements can not be met with Morse. 

Good point about the added weight.  To my mind, the weight itself is not an issue at all  since these 'clients' are not moving about. They're in their BOLs hunkered down for the duration.

One thing I've been trying to stress, however, is the 12v power requirements necessary for the hardware.  Like a computer.  I'm pressuring them, as best I can to ensure the use of laptops rather than desktops.

Absolutely; send me WL2K mail!  Better yet, send me something daily.  Always good to stress the system(s)

73

Luck, WA4STO
http://www.qrz.com/db/wa4sto (http://www.qrz.com/db/wa4sto)
Title: Re: Building your own digital network
Post by: Quietguy on June 20, 2013, 07:15:24 PM
Gil, you are right, Pactor/Winmor is not a good choice for pedestrian mobile but it is no problem in a motor vehicle.  However - for me personally - going pedestrian mobile in a bug out situation is no longer a viable alternative.  Getting old (and the accompanying problems) sucks, but it beats the alternative.  Choose your retirement location carefully because you probably won't be leaving it soon.

Quote
I can see how Winlink would be very useful in sending long text documents that would take forever to send with Morse code.

Even better, Pactor/Winmor can send attachments that cannot  be sent by CW.  One day a few years ago I checked my system for incoming mail and found a photo of a friend's new sailboat  - that image had been sent directly from his antenna to my antenna with nothing but 3000 miles of ether between them.  That image could have been a photocopy of an instruction manual for an urgently needed equipment repair, a PDF file of needed information or maybe pages out of a medical self-help manual.  It was all just bits and bytes to the software, it didn't care what the content was. 

Which brings up another point - the software doesn't care what the content is, but the WL2K operators do.  Messages have to comply with FCC ham regulations, and they are required to verify compliance.  It is my understanding that a petition was filed to make relay stations exempt from verifying compliance, but the FCC left the compliance burden on the station which first accepts the traffic.  I have no idea how close WL2K stations monitor incoming traffic, I'm sure it varies among operators.  Under normal conditions that is not a problem; I always try to operate my station according to the rules.

But, if you want some opsec you need to go peer to peer.  It is very hard for normal people to monitor the compressed message transfer between two stations.  I assume the government can or presumably they wouldn't permit the mode.  One way people communicating amongst themselves can make a peer to peer system work well is to establish times of day when propagation should be good, and to agree on a schedule of band/frequency monitoring.

Just like any other aspect of prepping, this is something that should be worked out before "It" happens, not after.

Wally
Title: Re: Building your own digital network
Post by: Geek on June 21, 2013, 08:15:17 AM
To make this thread whole, I suggest revising the opening post to include all the hardware bits needed, right down to the cables.

Regarding the gear required, I would like to see the software working on some of the tablets that are available.  The software should run on a Windows 8 tablet, but I haven't heard if anyone has tested it.  Getting it to run on Apple and Android devices would be fantastic.

I wish to get this running as well, but I am currently striving for more basic capabilities.  Thanks to a local Elmer, I am close to getting 2m packet email going.  I'll post something about that once it works for me.
Title: Re: Building your own digital network
Post by: RadioRay on June 21, 2013, 09:44:57 AM
So Far - RMSexpress/WINMOR only runs on Windoze systems;  whether on the tablet, I do not know. 

iPhone has PSK31 digital mode apps and HF weather fax for reading on-air weather charts (handy).  I have "PSKer" and "HFfax" and am happy with both for monitoring, though I much prefer Morse. So far, no ARQ/error correction 'mail worthy' modes on the iPhone/iPod Touch that I am aware of. 

de RadioRay ..._ ._
Title: Re: Building your own digital network
Post by: KC9TNH on June 21, 2013, 11:29:11 AM
Just like any other aspect of prepping, this is something that should be worked out before "It" happens, not after.

Wally
X-ring. In particular, station-to-station needs to be practiced beforehand. The fixed stations acting as WINMOR relays typically have pretty good fixed antenna systems for hearing our puny signals. Not surprisingly, I'd bet within a given region many of the same stations are dropped into folks' RMS Express 'favorites'. Having a network based on predictable fixed locations is good; developing a network (e.g., peer mode digital or whatever) involves at least one more thing first before playing with hardware.

People.

So whether it's a regular Saturday AM ragchew on 2m, a local or regional sked with a low antenna on 75m, a CW sked both for checking into how each other are doing & and to keep your chops up, or digital traffic handling with others who are preparing - develop that human terrain. (In more primitive times, those much-decried SSB "stupid roll-call" nets had a purpose where neighbors can be many miles away; in some places they still do.)

But whatever suits your purpose, the rest is just hardware without it. I like Geek's approach to participating in something, with someone, that is local and doable; likewise those who have a regular CW sked with each other, or have worked out some regular interval that 'someone' is going to get a WINMOR message from them. Everyone's needs are likely different; answer that question & drive on con gusto.

(Personally, in an event that would negate all the RMS relays, I've got other stuff to worry about.)

Just my $.02 adjusted down for the euro-model.  ;D
Title: Building your own digital network
Post by: White Tiger on June 21, 2013, 12:01:23 PM
From this little iPad I've downloaded an app that allows me to hold near a speaker...and it will decode Morse.

Apparently, it can also do the same thing with PSK31...but I still have no way of sending anything...so, I need to download WL2K/RMS Express/WinMor?
Title: Re: Building your own digital network
Post by: WA4STO on July 06, 2013, 06:54:28 PM
WhiteTiger asks:  "You'll be able to amplify that CW/digital signal to a point where you really will be heard in Vladivostok now!?"

Well, it's really odd.  I sold an antenna that was exceptional on the bands that actually propagate to dear old Vlad in Vlad, in favor of a home-brewed wire antenna (270' long horizontal loop) that works well on 80 and 40, which the old vertical did not.

So now I might be able to QSO ole Vlad and then again maybe not.  But that doesn't matter to me at this point, cuz I'm much more interested in the public service communications aspects of ham radio and I haven't been on anything other than 80 and 40 in months, even though the loop (and the tuner) will do all the other bands just fine.

So, to your question, the amplifier would be very useful, not for digital -- that stuff works superbly with 40 - 50 watts.  Now, that's mostly because the digital stations that I'm interested in will scan the various bands, searching for my miserable 50 watts, and will be successful due to the BAND, not the power levels...

So why the amp?  Because I still handle a fair amount of traffic on CW.  No automatic relays there.  No nodes.  Just brain power and well-equipped ears.   (neither of which would be MINE) And on 80 meters  in the summertime, I'd rather be providing the poor slobs on the other end of my keyer with a better signal, by way of the amp.

'Course, that doesn't help my receiving ability on those very same summertime 80 meter QRN-filled frequencies.  But as it turns out, I send a LOT more traffic than I receive.  The guys that send to me; they're using amps.  I get it.

73

LH

Title: Building your own digital network
Post by: White Tiger on July 07, 2013, 03:15:09 AM
The guys that send to me; they're using amps.  I get it.

And so do I, now.

Thanks!
Title: Re: Building your own digital network
Post by: WA4STO on July 07, 2013, 03:00:02 PM
White Tiger:

Dunno if you've noticed, as it's fairly transparent, but the messages I've sent you recently have been sent by way of WL2K/Winmor, not via the internet.

Which stresses the system, and that's good.  More important, perhaps, is that it forces me to consider the notion that I'm actually prepping in my own silly way.

Prepping for what, exactly?

Oh, lack of commercial power for one.  Everything in my shack can be run from the big batteries if necessary.  And if the antenna (hunk of wire) manages to come down out of the trees, I'm ok with that too, unless the house has fallen down around the BOL and I can't get out to throw the hammer up in the branches once again.  And if that happens, come to think of it, I've got bigger problems to consider.

And lack of internet infrastructure for another.

Wally's got me thinkin.  Again.  Happens, occasionally.  The high speed SCS modem runs off of 12 volts which is in tune with the whole notion of prepping, whereas that amplifier I'm considering?  Not so much...

73

Luck, WA4STO
Title: Re: Building your own digital network
Post by: Quietguy on July 07, 2013, 07:06:42 PM
Although I value WL2K as a backup email service, my focus here is on peer to peer use among friends.  When you and your friends establish a peer to peer network you have a system for helping each other that does not rely on any third parties or outside infrastructure.

I see several major benefits the SCS modems have over Winmor or Pactor 1 (put in whatever order seems important to you at the time):

- Weak signal/poor conditions performance.  A P3 connection can be established when the signal cannot be heard in the noise.  It may be too error-prone to sustain a file transfer, but it tells you the target station is there, so you can try again when conditions improve.

-  Much higher data rates permit much larger file size transfers within a reasonable length of time.  These files may be instruction manual PDFs, damage assessment photos, medical care information or recipes for 47 ways to prepare tasty dried beans and rice dishes.  It's all just bits and bytes to the system.

- Airmail will use rig CAT control and an SCS modem to create a multi-band frequency scanning system.*  Airmail accommodates a scan list and will use any of the SCS modems to sequentially listen for incoming connections.**

- The significance of frequency scanning should not be overlooked.  It removes the need for operators to be on duty at both ends before messages can be transferred.  An operator can choose the most appropriate frequency for the given time without regard to what the operator at the other end is doing.  If there are two or more standard frequencies within one band (usually) interference can be avoided.

* Note that scanning 24/7 for long periods puts a lot of wear and tear on band switching relays.  If the transceiver is one of those with solid state band switching then this is no problem - but it is something to keep in mind when using a rig like an Icom 706MkIIg.  Of course, scanning several frequencies within a single band doesn't switch the relays.  However, there is nothing to stop a user from establishing a scanning protocol with friends; such a protocol could establish standard scan times and durations or trigger events that would initiate scanning.

** Note that some SCS modems list "scanning" as a feature, but some do not - they are referring to the modem controlling the scan without benefit of a computer, acting like the old packet mail boxes where messages are stored in the modem itself.  Any of them can coordinate with Airmail, where Airmail is in control of the scanning.  My PTC-IIex does not have the "scanning" feature but the combination of Airmail and the modem scans quite nicely.

Some people don't see much value in a system like this; they feel that in a "hard times" situation there won't be time for chit-chat with people across the state/country.  On the other hand, maybe one of the people on the network happens to be a medical doctor who can give you long distance assistance in treating a serious injury.  Or maybe one person is a first class mechanic who can tell you how to get that critical piece of equipment back in service after you send him a photo of the damage.

Or, maybe you just want a new recipe for beans and rice.
Wally
Title: Re: Building your own digital network
Post by: WA4STO on July 24, 2013, 04:56:56 PM
Wally - my apologies for not having seen this for a couple of weeks.  Good info, and it's got me thinking.  Again. 

What I've been wondering now is how the guys who scan multiple bands do so with regard to antennas.

In my case, I've got things set up such that I'd have to manually twist and twiddle  my Palstar tuner every time I want the 270' loop to miraculously become 'resonant' on the new band.

I'm guessing that the guys who are more or less successful do it by way of a multiband vertical which kinda/sorta works although not very efficiently.  No tuner needed there.

Or perhaps a fan dipole of some sort.  Anything that doesn't require a tuner.

O.T.O.H. my IC-7000 does have an automatic tuner, and I THINK I can set it up so that it will always 'tune' whenever it transmits.  Would that work, maybe?

Still, it would have to be resonant somewhere.  Say 40 meters at a given time.  Meaning that it wouldn't hear (not very well anyway) something coming in on 80.

I'm confused.  Being a ham for 43 years will do that.  Maybe I should pretend I'm a newbie again.  Wait, that was no fun either.

73

Luck, WA4STO
Title: Re: Building your own digital network
Post by: Quietguy on July 24, 2013, 06:19:42 PM
All of my scanning has been done with wire antennas and an LDG RT-11 auto-tuner (hereinafter called "auto-coupler" to keep RadioRay's teeth from being ground down completely) that is controlled by an IC-706MkIIg. I have used an 80m dipole/doublet fed with window line as well as a coax fed 80/40/20 fan dipole.  Right now I'm using the 80m legs of the 80/40/20 fan dipole because the 40 and 20 meter legs fell.  Time for some maintenance I guess; it works fine on 80 and 20 but high SWR on 40 (even multiple of 80).

I have lots of trees but not lots of help, so I am usually putting these things up by myself.  So, I have cut the wire lengths to be reasonably close but rely on the auto-coupler to bring it in.  That hasn't been a problem - when the station is scanning and a call comes in, the radio will automatically go into "Tune" mode when it keys up.  The RT-11 finishes matching quickly enough to allow the connection to be established normally.  When the connection is finished the system resumes scanning.

The RT-11 auto-coupler has been discontinued but current LDG models are superior, in that they have memories and will recall match settings for frequencies they has seen before.  That (allegedly) shortens the cycle considerably, but the time delay has not been a problem for me.

When my antenna was in good shape scanning 80, 40, 30  and 20 meters was no problem.  30 sometimes gave a little RF in the shack and if I were going to do another fan dipole I might consider adding 30 m legs to it.  What I'm actually planning is a 110 foot window line fed doublet per the DX Engineering recommendations for one of their baluns.  They say it is good for all bands if the feedline length is correct and it is mounted less than 1/2 wavelength above ground - which for 80 m is about 130 feet.  I'll only be up about 50 feet, which is where I was before.

Wally
Title: Re: Building your own digital network
Post by: WA4STO on July 24, 2013, 07:28:47 PM
Wally -

I never would have guessed that the LDG (which is what I have as well) would do such a wide amount of tuning.

I really should put it back in line and see what happens.  I'm guessing that I'll have to come up with a balun first.

All of this is pushing me to the point where I may opt for the SCS modem rather than the HF amp.

Since you brought up Airmail previously, here's a change of topic for ya:

I've been looking for a way to run a 2 meter packet BBS and I wasn't too keen on the idea of going with something as complicated as BPQ, although that was at one time my favorite choice.

Today, however, while digging through Airmail, I discovered that there's a "VHF Packet Server" setup routine.  Hmmm!  What do you know about that?  Should I expect to be able to use Airmail (already familiar...) for that?

Trying to think down the rut a piece, I can't help but wonder how 'automatic' such a BBS would be.  And I'm wondering if, somehow, it's smart enough to know how to take traffic in on the VHF packet side, and magically format said traffic so that it will somehow be OK on the HF Pactor side.  Think that might be possible? 

I have no difficulty with the notion of having to manually format what little traffic I might get before it gets transported over to the HF side, but I am puzzling over what value there would have been if the Airmail coder(s) did NOT make that occur automatically.

Best 73

Luck, WA4STO
Title: Re: Building your own digital network
Post by: Quietguy on July 24, 2013, 09:00:05 PM
I don't know about Airmail's packet server - I have used the Airmail packet client and it works like the HF client only maybe a little less stable.  A local friend was trying to set up a peer to peer vhf network and had problems.  He and I tried several experiments linking through a digi-peater and had limited success.  It turns out my signal to the digi-peater is marginal; sometimes it works and sometimes it doesn't. 

However, he set up two stations at his home and had problems consistently linking between the two using Airmail.  Sometimes it worked flawlessly but occasionally it would go deaf and wouldn't connect.  The only way to recover was to shut down both instances of Airmail and restart.  Then it would be fine - for awhile.  While we were trying our experiments we experienced the same failure but it was hard to get a feel for what was going on since I didn't have a reliable link to the digi-peater.  As far as I know he was trying to use Airmail Packet client peer to peer; I don't know if he tried the packet server.

I don't have VHF simplex paths to any locals running Airmail so I haven't explored it too much.  It works with WL2K if my signal is good to the VHF-RMS, but that is hit and miss.  I'm surrounded by lots of hills and trees.

I haven't gone through the specs of the new SCS modems, but my PTC-IIex does both HF and VHF but not at the same time.  I have to shut down the HF terminal to open the VHF window (actually, Airmail does that automatically).  Fortunately, no cable changes are required because Airmail automatically switches the IC-706 to the right band/frequency.  The PTC-IIpro would do both simultaneously with two radios, but it required adding another module to the base modem, which upped the price noticeably.

Anyway, it looks like the VHF packet capability of Airmail could use some improvement, but it is not likely to happen.  Airmail has been flawless - for me - on HF and that seems to be what the author was concerned with.  The WL2K people have moved away from Airmail and strongly endorse RMS Express... but RMS Express does not support peer to peer on VHF packet, although it does on HF.  That's what put my friend in a bind - RMS Express doesn't support VHF peer to peer but Airmail does... but Airmail seemed to be buggy on the VHF side.

I have not worked with RMS Express or any other WL2K-developed software so I don't know what their capabilities are or how they would fit in with a "private" mailbox system.  I guess I should load RMS Express and quit guessing about it.  It's just that Airmail on HF has met my needs for so long that I don't often think about alternatives.

Wally
Title: Re: Building your own digital network
Post by: Rob_ma on July 25, 2013, 11:38:27 AM
Are there any good newbie books/websites available? I know someone who would like to get into digital comms but will be starting on the ground floor. They would like some basic info to build up their knowledge base.

- Rob
Title: Re: Building your own digital network
Post by: Rob_ma on July 25, 2013, 12:13:40 PM
Thank you. That is a good start for him and I'll pass along your offer. He has technical experience but not in radio (which I am slowly correcting ;) ). He's the type who reads a mountain of information before he jumps in to get his hands dirty. I told him that real techies don't RTFM (Read The "Fabulous" Manual). :D

Any other recommendations are appreciated.

- Rob
Title: Re: Building your own digital network
Post by: Kayden on July 25, 2013, 11:40:06 PM
Anyway, it looks like the VHF packet capability of Airmail could use some improvement, but it is not likely to happen.  Airmail has been flawless - for me - on HF and that seems to be what the author was concerned with.  The WL2K people have moved away from Airmail and strongly endorse RMS Express... but RMS Express does not support peer to peer on VHF packet, although it does on HF.  That's what put my friend in a bind - RMS Express doesn't support VHF peer to peer but Airmail does... but Airmail seemed to be buggy on the VHF side.

My humble self just pulled up his RMS Express client and was able to select Packet P2P under his Open Session dropdown. In fact, it appears the only P2P they haven't (finally) implemented is Telnet.

Or am I misunderstanding? I haven't used it, yet, I don't know anyone else here who would use P2P packet as they would either use Winmor P2P or WL2K, or they would use Packet WL2K.
Title: Re: Building your own digital network
Post by: Quietguy on July 26, 2013, 03:54:32 AM
No, I don't think you are misunderstanding - either I misunderstood my friend (although I don't think so) or his version of RMS Express is older and that function has been added.  I probably should load RMS Express myself and see what it looks like.

Thanks for the comment; it has me curious what happened on his end.
Wally