Are digital modes practical for prepping?

Started by gil, September 09, 2012, 01:19:29 PM

Previous topic - Next topic

deanathpc

HF seems to be the only thing used for digital mode.  What about VHF or UHF?  Yes I know shorter range.  But for those of us who can't afford an HF rig and / or o.ly have a tech license we are limited as to what we can play around with.

Mitch

Everything VHF/UHF that allows voice transmitions allows data also.

You won't hear it as often just because the pool you are swimming in is primarily dominated by repeater users and data modes bouncing off repeaters is generally frowned upon. (Unless it's something like a Dstar repeater- then voice is frowned upon!)

It's there though... Especially in a populated area like Houston. There's no harm in going to a traditionally simplex channel and calling CQ to see who answers. I wouldn't use the national simplex calling frequencies (146.52 and 446 MHz). For any who don't know the "generally accepted use" for different frequencies in the bandplan here is one source:

http://www.arrl.org/band-plan-1

I also imagine a large portion of those "repeater only crowd" may be newer  HAMs with handhelds who haven't dreamed of trying to hook them up to a computer yet.


gil

Quotethose of us who can't afford an HF rig

It is common belief that HF radios are more expensive than VHF. Many are, because of the features they offer, different modes and more power. It is however not always true. There are HF radios available from $30 in kit form to $300, SSB factory-built single-banders. Ebay is also full of HF radios for around $300 that still work perfectly fine.

I could set-up a digital mode station for $670, including Radio, interface and computer, all brand spanking new... (MFJ-94xx, Signalink USB & cheap laptop). You don't even need the Signalink box. The Fldigi manual has a schematic for a TX interface that costs only a few bucks.

HF on a budget is possible, you won't have as much choice, but it will work as well.

Gil.

deanathpc

Hmm interesting Gil.  The only HF I really know about are what I dealt with in the Marine Corps.  So I do understand HF also.

It's just the ham versions I don't know.  So much marketing hype. Bells and whistles are plentiful.  Plus I'm limited having my tech license.  Just can't absorb the gen class material.

Dean
KC2MVB

gil

Hello Dean,

Look at these then (your license allows you 10m voice ops from 28.3 to 28.5):

http://www.mfjenterprises.com/Product.php?productid=MFJ-9410X
http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=HTX-10+transceiver&_sacat=0&_from=R40

You can also operate CW on many HF bands with a Tech. license.

Gil.

deanathpc


KC9TNH

Quote from: gil on October 11, 2012, 11:06:39 AMHF on a budget is possible, you won't have as much choice, but it will work as well.

Gil.
Dean, good advice from gil.

One source (many really) often overlooked when folks look at the cost of HF is buying used. If you peruse the 2 most common forum classifieds, as well as QTH.com, you will get a feel for who's a "solid" presence there. Hams of many years will often swapout gear like changing clothes. Some new 'thing' comes out & they gotta have it, or they get a bigger base because they get tired of drilling thru sub-menus, or their eyes are going & they want a bigger display... any number of reasons.

A good time to peruse is over the winter while you define pretty much what your focus areas are gonna be - which will help define what equipment might meet your needs. Spring is a good time to buy because of sales of new models, hamfests & people getting tax refunds to help them get the latest/greatest. They might unload a perfectly good tried/proven HF base rig with most stuff you need in order to subsidize their next purchase (or recoup what they already spent to insure "domestic tranquility" with the household Chief Financial Officer).

Maybe figure out primary & secondary goals and go window-shopping without letting new sticker shock be your limiting factor. Working that out will help narrow down your 'list' because you'll be able to evaluate whether something would be worthwhile based on what else you might have to bring to the table.
:)

WA4STO

Are digital modes practical for prepping?  More and more often, the answer is proving to be "YOU BETCHA!"

Almost two months ago, KC9TNH was musing about the following possibilities:



Quote from: KC9TNH on October 09, 2012, 03:30:17 PMThe reason I have decided to investigate digital modes, in particular being able to link into email using HF, is because there may come a time when I might want to do that, for a variety of reasons.

It  could be a man-made event, e.g., the proverbial blue-helmets are rolling down the interstate and have crossed the state border and Big Sis is controlling the media story.

Either way it could be that I need to convey some larger amount of information to an outside entity, even OCONUS, who may not have radio skills, but whose influence I need to bring to bear to effect some outcome in my favor.

I might want to get some ground-truth out to a non-operator about conditions as a result of this natural event.

I might want to get some ground-truth out to a sympathetic country who may exert or rally political influence against a domestic oppressor OR to an off-shore floating broadcast station who can get the real story out.

Some of these things, well I've seen them occur in the past.  e.g. the ARC used radio amateurs to disseminate a list of survivors from within a disaster zone.  Sure made it a lot easier than trying to deal with health and welfare requests by the bajillions on an incoming basis.

Some of Wes's suggested scenarios are even more far-reaching.  But they can in fact have a solution within the ham radio digital modes.

Consider his last scenario.  Frightening, yes?  But in my testing of Winmor systems in the past couple of daze, I've discovered that there are international Winmor stations located all over the planet, which are up and running 24/7 and ready to disseminate the information that YOU deem to be true.

Let's go all paranoid and conspiratorial here for a moment.  The blue helmets have in fact taken the streets, taken down any semblance of internet connectivity,  kept everybody in their homes and/or compounds, and -- oh yah -- the electrical grid went bi-bi some weeks back.

Winmor allows "group" addresses, so if I have a requirement to  generate correct (as opposed to media specified) information to the world (literally), I can do that.  Thus, the fact that martial law has been implemented can be transmitted to 20 international outlets in pretty quick order.  Many other scenarios can be planned for in advance.  The truth gets out, far and wide.

I also noticed that of  the NBEMS modes, some can be coerced into doing "multicast" transmissions, coupled with error-correction.  This means that you can transmit your emergency bulletin to numerous stations simultaneously, with the expectation that the receiving stations will query your system for any "fills" or gaps in data which were not received correctly.

This is certainly a fine time to be a radio amateur. 

I'm looking now for others here who would like to participate in related preparations with Winmor.  We need to stress the systems with overloads of test messages to each other, so as to determine how badly, if at all, our systems will be affected when the S hits the F.  Any takers?

Best 73 de WA4STO

White Tiger

#23
This scenario is more realistic than anyone knows...after Thanksgiving dinner (my favorite holiday, due to its lack of commercialization)...a friend of the family, with libertarian passions related a story: he has plastered his vehicle with quotes from the founding fathers, Von Mises, etc., he went to fill-up his tank (a new Friday, habit), and a retired fellow walked up to him and started a conversation. This gentleman identified himself a former special forces. He mentioned that there were many folks in this country who seem to dismiss the idea that our soldiers would raise arms against their own people. Seems there is already a plan in place to address this - the Blue Hats will be here, but they will be battle tested forces from Germany, Serbia, Croatia, etc., - and they will have no compunction whatsoever about raising a weapon to put down any civil unrest/implement martial law. Each of these forces have seen America do the same in their own respective countries for many years doing just the same thing...which apparently has bred in them a get-even-ism...so, there's that...

...I was also informed that a very large Chinese military base exists 50 miles south of the Mexican border...

The "trouble" areas (where an authoritarian type government might encounter trouble), are well known to TPTB, and it, appears they've taken careful consideration of these issues.

It's time we made plans accordingly - it's why My next prepp - is to get off grid...quick,

...you know what's really interesting, in this very large country it's very near.y impossible to find a spot in a rural area that doesn't have a military base/fort!?

but that won't be the main focus - the cities will be the main focus.

Digital modes are calling...but not for the sake of a hobby....
If you're looking for me, you're probably looking in the wrong place.

KC9TNH

Quote from: WA4STO on November 23, 2012, 09:59:51 AMI'm looking now for others here who would like to participate in related preparations with Winmor.  We need to stress the systems with overloads of test messages to each other, so as to determine how badly, if at all, our systems will be affected when the S hits the F.  Any takers?

Best 73 de WA4STO
[/color]
I'm up for documenting some things, ways to do stuff, and different things to have in the bag. I'd personally recommend against attempting to stress the system (certainly espoused publicly) as it is still prop dependent, and a capability that is actually used, while being somewhat "dormant" from a prepper perspective. But, I think regular testing is a good thing. These access points are out there in place & supported by other operators and, like a repeater, the last thing I'd want them to think is that their efforts are for nought and they'll tear it down & re-purpose the equipment.

It's also difficult to determine who else keeps it as a tool in the bag when "the event" nips internet content in the bud. (That is why many, in normal use, advocate exchanging email that's NON-emergent using the Telnet capability, saving HF bandwidth for true EMCOMMs.) In one of the scenarios I mentioned above, it might be worthwhile to have some contact info for OCONUS folks receptive to the ground-truth before it becomes impossible to look up their "online" info. Nothing really to do with ham radio, but such a list could be a good thing to have if the indicators go that way.

An example of my starting efforts (read "baby steps") in this are along the lines of what is my exposure time for payload 'x' and that includes attachments, going both ways, creating the inbound traffic from my regular email account.

One other thing I noted today was another reason I like the lower power requirements. If the band is shifting in the middle of a transmission one can get into that constant ack-nack cycle and the repetitive attempts can get a bit heated, especially for a solid-state unit in what is basically long bursts of "key down." Not needing alot of output power is a big plus and keeps the finals happy.

:)

WA4STO

Quote from: KC9TNH on November 23, 2012, 05:22:39 PM

One other thing I noted today was another reason I like the lower power requirements. If the band is shifting in the middle of a transmission one can get into that constant ack-nack cycle and the repetitive attempts can get a bit heated, especially for a solid-state unit in what is basically long bursts of "key down." Not needing alot of output power is a big plus and keeps the finals happy.

:)

Yes, indeedee.  In the distant past, when using Ten-Tec rigs, I never had to be concerned with the 100% duty cycle of digital transmissions, which back then, was RTTY only.  Ten-Tec had a 100% duty cycle on their finals so "full" power was fine.

After that, I never really ran into such wonderful specs, meaning that I always kept the power down to a little under half.  In the case of my Icom IC-7000 today, I typically run 40 watts.

But that's MORE than enough, partly because Winmor systems frequently scan all the HF bands.  So if 40 meters (my mainstay, apparently) doesn't let me in, 80 or 20 likely will.  Life in the RF fast lane is good.

73 de Luck, WA4STO

KC9TNH

After getting back from #1's flooded basement late last night (sorry gil, too pooped for a QSO) I went to transmit my last WINMOR test I had queued up to do that day (best laid plans of mice, etc....) and couldn't raise anyone, including the somewhat local-to-me stations on 80m, who presented themselves to me suddenly in the top 1/3 of my list. Then I noticed the aurora had dipped down below Hudson Bay, which is a sure sign that some signals are squashed, probably mine too.  So, as the infantry likes to say, "the enemy gets a vote."  Well, so does Mother Nature.  Sometimes, stuff just happens.

(And, yes, if I'd had a "gotta make" sked with someone, my backup window would've been CW, in an appropriate part of the plan.)
WINMOR remains a very good tool, like a shovel. Even so, sometimes the ground freezes.
8)

cockpitbob

OK, I'm in.  I just ordered my Christmas present.  A Signalink USB with cable for my FT-857. 

I'm really itching to play with Winmore.  My 14 year old son has his General but hasn't done much.  I think digital modes will be enough like texting and emailing that it could get him back into the hobby.  Also, on my bucket list is EME and most people seem to be using digital modes because of their ability to work incredibly weak signals.

madball13

Quote from: cockpitbob on December 08, 2012, 09:45:05 PM
OK, I'm in.  I just ordered my Christmas present.  A Signalink USB with cable for my FT-857. 

I'm really itching to play with Winmore.  My 14 year old son has his General but hasn't done much.  I think digital modes will be enough like texting and emailing that it could get him back into the hobby.  Also, on my bucket list is EME and most people seem to be using digital modes because of their ability to work incredibly weak signals.

Just got my 817 hooked up to the computer for PSK. After lots of frustration i was able to figure it out. Recently during an EMCOM meeting at my club the president showcased the possibilities of using digital modes over the repeater. There are a lots of digital modes and they all seem to have there benefit based on data you want to transmit. PSK125 (???) for example uses a higher bandwidth but can get a lot of data transmitted in a short amount of time. My club supports lots of local activities like races and think it would be possible to digitize a list of racers and send it by PSK versus calling all the names out individually.

WA4STO

Quote from: madball13 on December 10, 2012, 07:55:38 AM
think it would be possible to digitize a list of racers and send it by PSK versus calling all the names out individually.

Heh, back in 1979, I did just that.  It was the first year for the hams to support the 24 hour horse riding and human running race through the mountains of Shenandoah, Page, and Frederick counties in Virginia.

Was it digital back then?  You bet.  RTTY. 

The ride/run officials were delighted to have a hard copy of who was where but man-oh-man, those Model 28 Teletypes were a stinker to heft up into the Jeep and unload at a horse barn in Front Royal.  After the race, do it all over again, in reverse.



The one thing we couldn't guarantee back then was accuracy of transmission.  Today, with Winmor and certain of the NBEMS modes, we can do that.

73 de Luck, WA4STO