Re: Igates and their use of digi paths

James Ewen


There’s a way to make things happen. You just go out and do it. 

Back in the late 90’s I wanted to get into APRS. I talked to a few buddies about it, and we all thought it would be interesting. But there was no APRS digipeaters around. The closest digi was 200 miles to the south. 

So I grabbed my old Kantronics KAM, figured out how to format a position packet (with much assistance from VE6SZR) and programmed that position packet into my beacon slot, and set the KAM to beacon every three minutes. Boom! First APRS station on the air in the Edmonton area. 

A couple days later VE6BCA configured his KPC-3 to act as a digi. Boom! First digi in Edmonton. It was just at a house on a 30 foot mast, but it was on the air, and my packets were being digipeated. 

Sometimes you just have to do it yourself. All of the digipeaters in Northern Alberta have been put in place by individuals. No club affiliation or support for just about all of them. Sometimes it is just easier to stay away from the politics that clubs can create and just get after it.  

So, if you have a station at your house, you could set it up as a digipeater. If it’s the only digipeater in the area, set it up as a full digi. If you have internet access and can do so, tie it into your digi and make it an I-gate as well. 

If at some point you can get a better spot and equipment, install a digi where it has advantageous coverage of your area. 

If people complain that “Nobody is doing anything around here.”, that means they are also part of the nobody. 

This really isn’t directly aimed at you Greg, but more of a generic discussion for anyone in a similar situation. You’ve just spurred me into responding. I’m not trying to call you out or anything. 

At some point if you realize you need to take the initiative, that group of “nobody”s looses a member, and things start to happen in your area. 

It can be a fair bit of work to start making things happen. It helps if you can find a couple people with a similar mindset. 

I was lucky to have a couple buddies that I could convince to join me on my projects. 

We started and built out the local APRS network. We built half a dozen HamHUDs so we could have mobile stations before Kenwood even thought of making the D700. We built payloads and launched dozens of high altitude balloons. 

I also agitate and get people working on other projects in other hobbies that I participate in. I do all of that because I’m selfish. I want to be able to play with stuff and have things that weren't here before. 

It can be difficult, if not impossible to do it alone, so find at least one other person that shares your interest, cultivate a friendship, and get after it. 

Nobody is going to do it unless somebody takes the initiative. 

Be a somebody, not a nobody. 

This now concludes my motivational speech for today! 😀


On Sun, Jun 21, 2020 at 10:56 AM Greg Depew <goatherder_4891@...> wrote:
What I'm saying is there is no network around me except me! That digi 30 miles away sometimes can't get into the network either and may disappear for hours or sometimes days from being on the maps. Unfortunately I don't have the money nor the locations to be able to put up a high level digi like needs to be. For now I'm it. 

Greg KB3KBR Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: James Ewen <ve6srv@...>
Date: 6/21/20 02:40 (GMT-05:00)
Subject: Re: [APRSISCE] Igates and their use of digi paths

While true the nearest permanent digi near me is 30 miles away and a mobile can't hit it unless it's about 15 miles away. I can't even reliably get into any of the digis in the area with the home station. 

So what you are describing is an area with no digipeater coverage. This is not a location for a fill-in digipeater, this area needs a full digipeater. 

A station operating in this area will not be able to participate in APRS operations on the digipeater network as there is no digipeater network in the area. A fill-in digipeater acts as a one way booster in the digipeater network. It will only ever act upon the first path element of a packet. If you put a fill-in digipeater into an area that is not covered by a main digipeater, then there is no way for any traffic (position reports, or more importantly messages) to get back into the area. 

Stations should never use WIDE1-1 anywhere other than as the first element in their outgoing path. Anyone wanting to get information back to station that only has a fill-in digipeater within range from an area 2 digits away would be forced to use WIDE1–1 As a second path element, which we all know is a very bad thing to do. 

Build the network properly and APRS works great. Build it incorrectly and you can have something that is a waste of time, effort, money, and just generally makes people resort to trying stupid things that cause more problems for everyone. 


On Sat, Jun 20, 2020 at 10:12 PM Greg Depew <goatherder_4891@...> wrote:
See below

Greg KB3KBR Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: James Ewen <ve6srv@...>
Date: 6/20/20 20:06 (GMT-05:00)
Subject: Re: [APRSISCE] Igates and their use of digi paths

A WIDE1-1 digipeater should be a located in an area where the main digipeaters can be heard and copied, but low powered handheld stations can’t get the attention of the main digipeater. A WIDE1-1 digipeater fills in and helps the low powered handheld stations get that first hop into the digipeater network. 

Agree wholeheartedly.

High powered (5 watts or more) mobile stations and fixed stations should never use an outgoing path of WIDE1-1. Digipeaters should be located at sites that provide advantageous coverage of the local area. A digipeater should NEVER EVER use WIDE1-1 as an outgoing path. If a digipeater is located such that it requires help from a home fill-in digipeater to be heard by the main digipeaters, it should shut down and removed from service. It is causing more congestion of the local network than it is helping. 

While true the nearest permanent digi near me is 30 miles away and a mobile can't hit it unless it's about 15 miles away. I can't even reliably get into any of the digis in the area with the home station. The network around here is almost non existent. My goal (which was solved with Lynn's advice of setting the gate to Wide1-1 to make the fill in pass the traffic back) was to use the fill in mobile in areas where I know the handheld can't get out. I used it in such a way tonight on our local lake using the handheld on the kayak to go back to mobile fill in and get back to the main digigate at my house. Successfully was able to send and receive messages to Wxbot and SMSGATE. 

If there are any other fill ins that my main digigate lights up I don't know where they are. Other than myself, theres only 2 other people running APRS in my county. One is using a deaf tracker and the other is in the process of getting a solar digi setup on his towns water tower which should increase the coverage to most of the southern part of the county. 

Unfortunately my local club has zero interest in APRS and when I approached our repeater guru about getting stuff on our main tower he shot me down with concerns of it desensing the repeater.  I would love to get high sites but not enough intrest has taken hold even after I held a presentation on it a couple years back. 

On Sat, Jun 20, 2020 at 10:44 AM Greg Depew <goatherder_4891@...> wrote:
Would it be better for me to change 4 to respond to Wide2-2 or have the 1 the igate put out Wide1-1 and maybe light up digis that are very far away? 

Sometimes I can get into a big digi in Ohio but I can't hear it back on anything but the -1, and I've seen my packets be delayed while they hop through the system on open days then get regated about a min later sometimes in Canada or a different place in Ohio. 

Greg KB3KBR Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Lynn Deffenbaugh <kj4erj@...>
Date: 6/19/20 19:48 (GMT-05:00)
Subject: Re: [APRSISCE] Igates and their use of digi paths

On 6/19/2020 6:38 PM, Greg Depew wrote:
Can you give a more complete description of what all is involved?

KB3KBR-11 is what station?  Software, TNC and radio please.

11 is a Yaesu Ft1d

Same for -4 (a WIDE1-1 digi) 

4 is a fill in digi , TinyTrak 4 with GPS and and FT 8800 in a go box programmed to only respond to Wide1-1 and it's own callsign 

Same for -1 (presumably a WIDE2 digi)

1 is APRSIS32 via sound card Signal link into an Ftm 350and is an igate and digi that responds to Wide1-1 and Wide2-2 

Same for the IGate and please include callsign-SSID with the other 3 pieces of the puzzle.

And some idea of who can copy who directly.  Can -1 copy the IGate directly or does the IGate need the boost from -4 to get to -1?  

1 is the igate, 4 is my mobile fill in that I'm using to get 11 back to the igate 

You've already mentioned that you can't hear -1 indoors, but only -4.  Can you copy the IGate indoors?  

When I'm at work inside our 911 center our grounding halo blocks just about everything. 4 is sitting in the truck in the parking lot and can hear 1 and 11. 11 can only hear 1 if it's out side and its iffy if 1 can hear 11 without either holding the antenna in the or more power.

If not, then can we assume the IGate is actually remote from your QTH, but -1 is local?

So, with that final line, it would seem that if you're IGate is using a WIDE1-1,WIDE2-1 path, then -4 will copy it and repeat it locally so that -11 can copy the response at the 911 center.  Without the WIDE1-1, -4 won't digipeat and -11 won't copy it.

The big issue you have is that the -11 HT can't copy the IGate directly when at the 911 center, and apparently there's no bigger digipeater that will digipeat the IGate and be copied by the -11 HT.  No amount of pathing is going to solve an issue of a marginal receiver (the HT) at some distance from the IGate without strong coverage.

But a WIDE1-1,WIDE2-1 path on the IGate should trigger the -4 digipeater to deliver a stronger packet to the HT.

Anyone have any better suggestion?

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

PS.  An external antenna that you can connect to the HT inside the 911 center would likely also solve your issue.  Apparently the -4 has bigger ears than the HT or it wouldn't copy the IGate while sitting in the parking lot.




Join to automatically receive all group messages.