Topics

No 2m but still an APRS igate?

Sander Pool <sander_pool@...>
 

Hi,

the radio looks interesting but without a 2m radio how could it reasonably be an APRS igate? I realize you can run APRS on many frequencies but it's not much use running an igate when no one is using your frequency. I'm asking because APRS is listed on the flyer. Actually it seems 2m is a more popular packet frequency for winlink2k as well but at least in that case there is no agreed upon frequency so you can run one on 70cm.

Thanks,

Sander W1SOP

"kc5zrq" <kc5zrq@...>
 

Really? VHF? I operate APRS and RMS Packet using UHF at 9600 baud. It works so much better than 1200 baud packet on VHF. The noise floor on UHF is usually lower. A typical ham dual-band antenna has higher gain on UHF than VHF. The bandwidth of 9600 baud AX.25 is more narrow than 1200 baud. There is lots more unused spectrum on UHF than VHF. I want UHF!

--- In UniversalDigitalRadio@..., Sander Pool <sander_pool@...> wrote:


Hi,

the radio looks interesting but without a 2m radio how could it
reasonably be an APRS igate? I realize you can run APRS on many
frequencies but it's not much use running an igate when no one is using
your frequency. I'm asking because APRS is listed on the flyer. Actually
it seems 2m is a more popular packet frequency for winlink2k as well but
at least in that case there is no agreed upon frequency so you can run
one on 70cm.

Thanks,

Sander W1SOP

Bill Vodall <wa7nwp@...>
 

the radio looks interesting but without a 2m radio how could it
reasonably be an APRS igate? I realize you can run APRS on many
frequencies but it's not much use running an igate when no one is using
your frequency. I'm asking because APRS is listed on the flyer.
The main reason I'd buy one of these radios today is to use as a home
digipeater and iGate for our 96UHF alternate APRS network. UHF and
9600 is plug and play with the Kenwood mobiles but doing 9k6 is a pain
with any other setup.

All you need to make an APRS alt channel is one (preferably two) IGate
on any other frequency. The hard part is getting folks to actually
make use of it. (9k6 is a disadvantage here too but that's another
discussion...)

73
Bill - WA7NWP

Sander Pool <sander_pool@...>
 


Right, if you have a local userbase that runs APRS on 70cm then this would be a great radio. It could even be an advantage that no one 'in the know' will be pinging your igate with 144.390 packets. But as a general purpose APRS igate it would not be very useful.

http://info.aprs.net/index.php?title=Frequencies

To be clear, I have nothing against UHF or any other frequency, of course. Clearly there are advantages to running 9600 baud packet over UHF. I was questioning the use of APRS in the flyer. I suppose anyone with the knowledge to set up a linux based APRS igate would not be confused and quickly see that it is not usable on the most often used frequencies.

73,

    Sander W1SOP

On 5/22/2012 12:59 PM, Bill Vodall wrote:
 

The main reason I'd buy one of these radios today is to use as a home
digipeater and iGate for our 96UHF alternate APRS network. UHF and
9600 is plug and play with the Kenwood mobiles but doing 9k6 is a pain
with any other setup.

All you need to make an APRS alt channel is one (preferably two) IGate
on any other frequency. The hard part is getting folks to actually
make use of it. (9k6 is a disadvantage here too but that's another
discussion...)

Perry Chamberlain <canoeman@...>
 

The 440 aprs packet frequency used is 445.925. In some areas, its dead quiet, in some its packed.
But there are 440 freqs to use aprs. It just means you have better propagation, no collisions and as long as your igated, it goes to the WEB apr IS.

Respectfully

Perry Chamberlain


On May 22, 2012, at 9:11 AM, Sander Pool <sander_pool@...> wrote:

 


Hi,

the radio looks interesting but without a 2m radio how could it
reasonably be an APRS igate? I realize you can run APRS on many
frequencies but it's not much use running an igate when no one is using
your frequency. I'm asking because APRS is listed on the flyer. Actually
it seems 2m is a more popular packet frequency for winlink2k as well but
at least in that case there is no agreed upon frequency so you can run
one on 70cm.

Thanks,

Sander W1SOP

"John D. Hays" <john@...>
 

Hi Sander,

Maybe I can clarify this a little bit.   If you look at the wiki information in the link you included, 144.39 nor 1200 baud is universally used for APRS or igates.  You will find there are UHF networks and 9600 baud networks, including 9600 baud UHF networks.

Obviously, anyone using a UDR56K for an APRS tracker is only going to be able to report to 70cm igates.   

The UDR56K was designed to be both a user radio and an infrastructure (igate, D-STAR gateway, AMPRNET, RMS, etc.) radio.  If you are using it in infrastructure, say as an igate, it can do that.  A frequency, modulation (FSK, GMSK, 4FSK) and baud rate (4800-56000) would be selected and the proper application loaded and run.  Any trackers would need to match the same combination.

A lot of thought went into the selection of the band and the modes under which the radio would operate.  

The concept of "Universal" Digital Radio means it can be used for more than one application.  So while one user might want to use it for 9600 baud APRS, another might want to run it at 56Kbps for file transfers in an RMS function, or to pass AMPRNET or D-STAR DATA traffic.   Yet another user might want to run D-STAR Voice or Codec-2.   

2 meters, suffers from being "too popular" -- in many countries it is only 2 mHz wide, with FM repeaters, weak signal, APRS, satellites, etc. all trying to squeeze into the band.  A 56Kbps signal is not permitted in the US FCC regulations on 2 meters and would not be friendly to other spectrum users if it were.   

The 219 and 222 band is interesting and may lend itself to a UDR type radio (the band is only available in a limited area such as US/Canada), so the thought is that it is better to use 70cm as a good place to start:
  • 10-30 mHz. of spectrum in most areas
  • reasonable feedline/connectors (compared to microwave)
  • descent propagation (not as good as 2m, obviously but better than 33/23 cm)
  • allows a data signal of up to 100 kHz bandwidth and 56 baud signal rate, with spectrum to support it
I believe that both tactical users (e.g. Emcomm) and experimenters will have a new world opened up to them with a less crowded spectrum.  In the US, it seems a lot of people think the lower end of 70cm is at 440 mHz., when there is an additional 10-20 mHz below that. (To me it's silly to try to squeeze APRS into 440-450, one proposal puts it on a frequency that is a repeater output in some band plans.)

Here's the good news though.  If you have a current igate on 2m, you can replace the computer with a UDR56K, attach a USB-to-Serial cable  to the TNC and radio to continue to service the 144.39 net, while offering 9600 baud or better APRS on the UDR56K's 70cm radio.  Then you would have a dual band igate with less power requirement (by loosing the computer) and a much smaller package.  Attach a diplexer and dual band antenna and you are ready to go.


John D. Hays
K7VE
PO Box 1223, Edmonds, WA 98020-1223 
  



On Tue, May 22, 2012 at 10:27 AM, Sander Pool <sander_pool@...> wrote:
 


Right, if you have a local userbase that runs APRS on 70cm then this would be a great radio. It could even be an advantage that no one 'in the know' will be pinging your igate with 144.390 packets. But as a general purpose APRS igate it would not be very useful.

http://info.aprs.net/index.php?title=Frequencies

To be clear, I have nothing against UHF or any other frequency, of course. Clearly there are advantages to running 9600 baud packet over UHF. I was questioning the use of APRS in the flyer. I suppose anyone with the knowledge to set up a linux based APRS igate would not be confused and quickly see that it is not usable on the most often used frequencies.

73,

    Sander W1SOP


Sander Pool <sander_pool@...>
 


I will tune my igate to 445.925 and see what I pick up over the next few days. Near as I can tell all local (CT/NY area) users are on 144.390 but maybe I'm missing out on a lot of traffic. I will also run my mobiles on that frequency to see if any other igates are listening. I don't think igates announce their frequency but if non-144.390 is common in the US it should probably be included so you can see on aprs.fi and other servers.

73,

    Sander W1SOP

On 5/22/2012 2:01 PM, Perry Chamberlain wrote:
 
The 440 aprs packet frequency used is 445.925. In some areas, its dead quiet, in some its packed.
But there are 440 freqs to use aprs. It just means you have better propagation, no collisions and as long as your igated, it goes to the WEB apr IS. 

Perry Chamberlain <canoeman@...>
 

That is a great idea, nice........... Im liking it even more .


 He said:
"Here's the good news though.  If you have a current igate on 2m, you can replace the computer with a UDR56K, attach a USB-to-Serial cable  to the TNC and radio to continue to service the 144.39 net, while offering 9600 baud or better APRS on the UDR56K's 70cm radio.  Then you would have a dual band igate with less power requirement (by loosing the computer) and a much smaller package.  Attach a diplexer and dual band antenna and you are ready to go."

Respectfully

Perry Chamberlain


On May 22, 2012, at 11:29 AM, "John D. Hays" <john@...> wrote:

Here's the good news though.  If you have a current igate on 2m, you can replace the computer with a UDR56K, attach a USB-to-Serial cable  to the TNC and radio to continue to service the 144.39 net, while offering 9600 baud or better APRS on the UDR56K's 70cm radio.  Then you would have a dual band igate with less power requirement (by loosing the computer) and a much smaller package.  Attach a diplexer and dual band antenna and you are ready to go.

Bill Vodall <wa7nwp@...>
 

(FSK, GMSK, 4FSK) and baud rate (4800-56000) would be selected and the
proper application loaded and run.  Any trackers would need to match the
same combination.
No 1200 baud? :-( True it's overkill for a UDR but it could be
useful at times...

Bill

Perry Chamberlain <canoeman@...>
 

Byonics tried to get a line of 440mhz trackers up, but no one was interested. Maybe now.


Respectfully

Perry Chamberlain


On May 22, 2012, at 12:12 PM, Bill Vodall <wa7nwp@...> wrote:

 

> (FSK, GMSK, 4FSK) and baud rate (4800-56000) would be selected and the
> proper application loaded and run.  Any trackers would need to match the
> same combination.

No 1200 baud? :-( True it's overkill for a UDR but it could be
useful at times...

Bill

"richark" <richark@...>
 

I don't think there is a 'universal' APRS channel for 70cm, like 144.39 is for 2m. Here in the Northwest, we use 440.800 for 9k6 APRS.

Not sure how official this list is, but it provides other alternatives around the world.

http://info.aprs.net/index.php?title=Frequencies

73,
Kenny, KU7M

--- In UniversalDigitalRadio@..., Sander Pool <sander_pool@...> wrote:


I will tune my igate to 445.925 and see what I pick up over the next few
days. Near as I can tell all local (CT/NY area) users are on 144.390 but
maybe I'm missing out on a lot of traffic. I will also run my mobiles on
that frequency to see if any other igates are listening. I don't think
igates announce their frequency but if non-144.390 is common in the US
it should probably be included so you can see on aprs.fi and other servers.

73,

Sander W1SOP

On 5/22/2012 2:01 PM, Perry Chamberlain wrote:
The 440 aprs packet frequency used is 445.925. In some areas, its dead
quiet, in some its packed.
But there are 440 freqs to use aprs. It just means you have better
propagation, no collisions and as long as your igated, it goes to the
WEB apr IS.

Joshua Mesilane <josh@...>
 

Hi All,

I LOVE what this radio stands for. I love the fact that it will be an open source radio, but is the hardware going to be open as well? PCB design, chip code, etc? Is the project going to be completely open source & open hardware, or only partially?

As for APRS. Here in VK we primarily use the 2m network with a nation-wide frequency of 145.175 and to a much lesser degree 70cm is used typically for experimental purposes. I run a 2m IGate at home using javAPRSSrvr and the idea of having this run on the device directly I think is exciting, however:

Will the radio be designed in such a way that if we wish to contribute to the project a "2m" version could be designed?
Are the RF components modular and would they allow for swapping? (So that third parties could easily design and produce open hardware alternative RF boards)
Is there any hope for an RS-232 port?

USB-Serial/USB devices in general are notoriously bad for crashing and rebooting in RF environments which can easily cause the serial port to lock up and you then need to remove and re-plug the serial port. I'm not so sure that I'd want to use my NMEA GPS via a USB/Serial adaptor (Or even an FTDI USB GPS) if it were going to be hard wired into a mobile installation. In that environment (IMO and in the field experience) RS232 is the only way to go. In some applications (Remote telemetry systems - And we're not just talking about HAM radio now) quite a lot of gear still uses RS232. I can see a MUCH wider use for this radio if the cost can be kept low, if it has interchangeable/configurable RF stage an RS232 capability. You could even aim for certification of the RF boards to comply with govt standards and market the product as an "open" alternative to the proprietary telemetry/data radios currently on the market.

Cheers,
Josh


On Wed, May 23, 2012 at 5:37 AM, richark <richark@...> wrote:
 

I don't think there is a 'universal' APRS channel for 70cm, like 144.39 is for 2m. Here in the Northwest, we use 440.800 for 9k6 APRS.

Not sure how official this list is, but it provides other alternatives around the world.

http://info.aprs.net/index.php?title=Frequencies

73,
Kenny, KU7M


--- In UniversalDigitalRadio@..., Sander Pool wrote:
>
>
> I will tune my igate to 445.925 and see what I pick up over the next few
> days. Near as I can tell all local (CT/NY area) users are on 144.390 but
> maybe I'm missing out on a lot of traffic. I will also run my mobiles on
> that frequency to see if any other igates are listening. I don't think
> igates announce their frequency but if non-144.390 is common in the US
> it should probably be included so you can see on aprs.fi and other servers.
>
> 73,
>
> Sander W1SOP
>
> On 5/22/2012 2:01 PM, Perry Chamberlain wrote:
> > The 440 aprs packet frequency used is 445.925. In some areas, its dead
> > quiet, in some its packed.
> > But there are 440 freqs to use aprs. It just means you have better
> > propagation, no collisions and as long as your igated, it goes to the
> > WEB apr IS.
>




"John" <john@...>
 

Hi Josh,


--- In UniversalDigitalRadio@..., Joshua Mesilane wrote:
>
> Hi All,
>
> I LOVE what this radio stands for. I love the fact that it will be an open
> source radio, but is the hardware going to be open as well? PCB design,
> chip code, etc? Is the project going to be completely open source & open
> hardware, or only partially?

This is a commercial product.  NorthWest Digital Radio has and is making significant investment to bring it to the marketplace.  The company's goal is to provide an open platform for amateur radio at an attractive price point.

The reality is that every modern piece of equipment has some proprietary intellectual property, and when someone manufacturers a product there is always a trade-off between cost and delivery.  It is often less expensive to buy parts than to make them, and when you buy parts you have to live within the terms of the purchase/license.  For example, to support many Digital Voice protocols you must use a proprietary Vocoder (this isn't just a D-STAR requirement, it applies to all current major Digital Voice protocols).  NWDR will offer a daughter card with a chip that does that, but can't reverse engineer and provide open source for intellectual property they do not own.

Sometimes you have to sign  restrictive agreements just to buy parts from some manufacturers.  This will be a barrier to sharing some low level details.

>
> Will the radio be designed in such a way that if we wish to contribute to
> the project a "2m" version could be designed?
> Are the RF components modular and would they allow for swapping? (So that
> third parties could easily design and produce open hardware alternative RF
> boards)

I won't comment on specific product plans (there are identified product concepts which will be worked on after the initial UDR is ready), but if this product sells well, that will motivate and help fund future products.  The basic design is such that the engineering to place the UDR is pretty straight forward for a few VHF/UHF bands.
 
> Is there any hope for an RS-232 port?

The design for the UDR56K4 is 1 Ethernet and 4 USB ports. 

>
> USB-Serial/USB devices in general are notoriously bad for crashing and
> rebooting in RF environments which can easily cause the serial port to lock
> up and you then need to remove and re-plug the serial port.

I have experienced this in other projects.  This is usually due to ingress via RF on cables.  Using good shielding, quality cables with ferrite chokes on both ends, and good grounding will often mitigate the problem.

> I'm not so sure
> that I'd want to use my NMEA GPS via a USB/Serial adaptor (Or even an FTDI
> USB GPS) if it were going to be hard wired into a mobile installation. In
> that environment (IMO and in the field experience) RS232 is the only way to
> go. 

Cables can be minimized or eliminated using certain form factors for the device,  another option is Bluetooth. (E.g. a bluetooth GPS or Audio device with a micro-adapter (no cable).

73 - John 

Joshua Mesilane <josh@...>
 

Hi John,

Thanks for the quick reply.

To avoid this getting too big I'll snip out the bits I'd like to add further comment/clarification to.

The reality is that every modern piece of equipment has some proprietary intellectual property, and when someone manufacturers a product there is always a trade-off between cost and delivery.  It is often less expensive to buy parts than to make them, and when you buy parts you have to live within the terms of the purchase/license.  For example, to support many Digital Voice protocols you must use a proprietary Vocoder (this isn't just a D-STAR requirement, it applies to all current major Digital Voice protocols).  NWDR will offer a daughter card with a chip that does that, but can't reverse engineer and provide open source for intellectual property they do not own.

Sometimes you have to sign  restrictive agreements just to buy parts from some manufacturers.  This will be a barrier to sharing some low level details.

Competely understand. I deploy and manage servers that exist predominantly in an open-source environment, however I know that some aspects of the various systems employed do need to interconnect with other proprietary systems which often also means proprietary licensing. I guess the open source and open hardware was more targeted at the design, build etc of the device as much as you can without breaching any existing proprietary licensing arrangements.

If however this is going to be a truly 100% proprietary hardware build (where none or little of the hardware design details are released), then that does take some of the excitement out of the product for me. That's not to say that the product is not without merit (And also not that I won't buy one) but the concept of an open-hardware platform (or even semi-open) as well as software to suit one's needs I think is really exciting. If this is only an open software platform then it does take a little of the excitement out of it. To me, that's kind of like saying "Here, we have this fantastic new radio bolted to a Linux PC - you're allowed to design software to run on the PC, but you're locked in to our API to the radio, and you're not allowed to play with the physical hardware". I know that my description is greatly simplified but isn't playing with hardware what HAMs do? Isn't it what we've been doing for years? Why should the open-ness stop at the software? I will re-iterate however that does not mean that I don't like the product, and also does not mean that i wouldn't buy one.
 

I won't comment on specific product plans (there are identified product concepts which will be worked on after the initial UDR is ready), but if this product sells well, that will motivate and help fund future products.  The basic design is such that the engineering to place the UDR is pretty straight forward for a few VHF/UHF bands.

So essentially at this stage, no. The RF side of the unit will be proprietary and closed, and we're locked in to when expansions are released by/for UDR however you may be suggesting that you're not entirely locking yourself in to 70cm, and that we should watch this space.
 
 
> Is there any hope for an RS-232 port?

The design for the UDR56K4 is 1 Ethernet and 4 USB ports. 

So that's an outright no?
 

I have experienced this in other projects.  This is usually due to ingress via RF on cables.  Using good shielding, quality cables with ferrite chokes on both ends, and good grounding will often mitigate the problem.

But this isn't also entirely unique to RF on cables. Things like Ignition spikes on the DC from the power supply in a car are inevitable and can be for the most part mitigated but do still exist. One can try to mitigate the noise/RF as much as possible however it's going to be a inevitability. I really think that not adding an RS-232 port is somewhat limiting the potential marker for the product. You really do have a wide market outside of HAM radio (and potentially a much wider market than HAM operators) if you can get your RF board certified, but the addition of an RS-232 port would be a requirement.
 


Cables can be minimized or eliminated using certain form factors for the device,  another option is Bluetooth. (E.g. a bluetooth GPS or Audio device with a micro-adapter (no cable).

I think you may have misunderstood what i was suggesting. It was more in relation to USB being unstable in mobile environments and resetting. Something that happens on USB and even moreso on bluetooth (even in stable environments). What I'm perhaps suggesting is that in a mobile environment what happenes if your aprs daemon loses connectivity to the gps? Will your daemon just hang or will it close and re-open the serial port. What happens if the USB device resets and creates a new serial port on the machine? I know these are more software issues, but they all essentially come down to the absense of a serial port.

Perhaps I'm harping on about RS232, but the thing is it's a reliable proven technology, and with so many HAMs out there already having RS232 gear, I think it's a HUGE omission. Particular considering that so many Auto Tuners, TNCs, and even other radios that you might interface with this radio often have inbuilt RS232 (Or TTL, which can be boosted with a MAX232) and to then have to rely on an unknown quantity - an USB - Serial adaptor (FWIW - I had a good quality known USB Serial adaptor blow up and take the Level converter in my TNC for my IGate about three weeks ago, so it DOES happen) when the addition of a RS232 port on the device would seem to make the device more flexible, and marketable.

Interesting to hear your thoughts. As I said, I do think that this in a fantastic product, and keep in mind this is only my opinion - nothing more.

Cheers,
Josh

--
VK3XJM
0416039082
josh@...
http://www.zindello.com.au/

"Tony Langdon, VK3JED" <vk3jed@...>
 

At 04:29 AM 5/23/2012, you wrote:

Here's the good news though. Â If you have a
current igate on 2m, you can replace the
computer with a UDR56K, attach a USB-to-Serial
cable  to the TNC and radio to continue to
service the 144.39 net, while offering 9600 baud
or better APRS on the UDR56K's 70cm radio. Â
Then you would have a dual band igate with less
power requirement (by loosing the computer) and
a much smaller package. Â Attach a diplexer and
dual band antenna and you are ready to go.
Now this is a neat idea!

73 de VK3JED / VK3IRL
http://vkradio.com

Sander Pool <sander_pool@...>
 


I was actually thinking of using a soundmodem to add a second TNC to my D710. The intent was to run Winlink 2000 on one and APRS on the other, from the same laptop. The radio does the -plexing. I could also do the gating between 2m and 70cm APRS in the same way.

Well, that's the theory anyway :)

I've been running igate W1SOP-3 on 445.925 for a while now but haven't received anything but my own test packets from a D72. I think in this area a dedicated 70cm igate is not the best investment of resources yet. Maybe in time.

73,

    Sander W1SOP

On 5/23/2012 5:25 AM, Tony Langdon, VK3JED wrote:
 

At 04:29 AM 5/23/2012, you wrote:

>Here's the good news though. Â If you have a
>current igate on 2m, you can replace the
>computer with a UDR56K, attach a USB-to-Serial
>cable  to the TNC and radio to continue to
>service the 144.39 net, while offering 9600 baud
>or better APRS on the UDR56K's 70cm radio. Â
>Then you would have a dual band igate with less
>power requirement (by loosing the computer) and
>a much smaller package. Â Attach a diplexer and
>dual band antenna and you are ready to go.

Now this is a neat idea!