Multiple nodes allowed? Good source of documentation for guidance?

#1 · February 15, 2024, 3:21 pm

Does NEGN allow a user to have multiple nodes and have those logged in to multiple hubs concurrently? i.e. Build a machine with 3 different radios, then connect to 7000, 732, 600 all from the same IP but different node numbers and different ports, for instance?

If so, can anyone who has experimented with this comment as to whether this resource is a good indicator of the process for having multiple nodes on a single machine?

https://wiki.allstarlink.org/wiki/Two_Nodes_on_One_Server

Something jumping out at me is that link omits the process to assign a unique port to additional nodes in iax.conf. Is anything else major missing there I would want to source and review to understand how the process works and could be executed?

Thanks,

Rob

#2 · February 15, 2024, 3:58 pm

I have never set up multiple Radio Nodes on one Raspberry Pi. I guess you could do it but good luck getting the RF interference sorted out. Running multiple nodes with radios or HATs/Dongles is hard enough.

To answer your question, yes it is allowed. I do it myself. One is connected to a Motorola CDM 1250 and the other has the little Amazon Dongle. I get interference between to two.

#3 · February 15, 2024, 4:28 pm

Hi Ray,

Thanks for that information. Especially the part about interference. I'm assuming this is even when they're over a wavelength apart? What is the approximate distance they're at and still causing issues?

I have my NEGN Node (462.650mhz) and my D-star hotspot (438.800mhz) ~ 8.5' from each other, and not true apples to apples since one is a 70cm wavelength vs the other being about 65cm I was optimistic that since they weren't interfering as long as kept the additional hardware for the nodes separated by 27" or more I'd be all good. Sounds like perhaps not and I've neglected to consider some other factor here? My amateur license class is technician, and I don't use my 10m privileges at present so my antenna knowledge is really down at the level of VHF/UHF repeater work from HTs and mobile units, thus always more to learn.

Thanks,

Rob

#4 · February 15, 2024, 5:10 pm

In my opinion the little HATs/Dongles are not very good radios and the just can't filter out the spurious emissions. GMRS does not have enough bandwidth between channels to keep everything where it should be when your separation is stuck to the confines of your house. In my case putting multiples nodes in my basement just caused the RF to bounce around until it got into my WiFi or another node.

It can be done, but takes a lot of patience and tinkering.

Ray

#5 · February 15, 2024, 5:24 pm

Hi Ray,

In your response you specifically cite the hat/dongle. Does that mean in your experience this problem largely restrained to the dongle having issue when the cdm1250 is in TX, but not the other way around? i.e. Does the Motorola exhibit good selectivity despite the GMRS channel separation limitations? Or is it really both ways?

Not that I'm going to run out and build a stack of cdm1250s, just trying to learn more!

Thanks,

Rob

#6 · February 15, 2024, 5:38 pm

It's both ways. The CDM is an old commercial radio so I can't really vouch for all CDMs, but mine gets interference just like the little radios. I will say this, the CDM is in direct line of sight with my node in my shack. If I moved the low power node to the basement, the node to node interference would be less but then I would have to deal with it getting into my WiFi.

#7 · February 15, 2024, 6:42 pm

Hi Ray.

Understood. Thanks for the clarification.

Relegating this one to the academic category for now, then. I have other signal interference issues around the home to solve before I start adding more nodes that could interfere with each other.

Thanks,

Rob

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Multiple nodes allowed? Good source of documentation for guidance?