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New Packet Radio

Ken Jamrogowicz
 

Damon and I are planning to try out the NPR (UHF high speed packet) modems being called "New Packet Radio"  we have parts and some assembled boards.

https://hackaday.io/project/164092-npr-new-packet-radio

Recently, other projects have take my available spare time, but this is in the pipeline. 

As you probably know, UHF data rates are presently limited by some arcane FCC regulations that never anticipated that you might want to do anything faster than 56k data, even on a band where 6 MHz wide channels are already permitted (for ATV). The developer of this (NPR) system never wanted his system to go this *slow* but has come to realize that a lot of hams in the US would use it, if it were FCC-compliant.  In the future, if someone gets the FCC to move regulations forward, these units can run at much faster data rates just by setting configuration parameters.  

This is a master-slave system (managed TDMA). One way to make it run fast is to have the master node be full-duplex.

My plan is to set up a full-duplex node here - tentatively operating with 423.225 MHz input and 428.225 MHz output (out of consideration of the other repeaters at this site).  It would have an IP connection to the 2/5 GHz AREDN mesh at this location and basically serve as an extension of the NoVA AREDN network.  

How exactly one would use this is entirely something to be discovered.  For starters, would provide an IP connection suitable for messaging using the software already employed in packet (Winlink, etc).  Just faster. 
It should be accessible from anywhere that you can hit one of the W4BRM repeaters with an HT - tree blockage only having a minor effect at this frequency.  You could use it as a local extension of your end of the AREDN network too.

you can find more info and links on 
https://www.arednmesh.org/comment/13498#comment-13498
https://cdn.hackaday.io/files/1640927020512128/NPR_advanced_guide_v2.2.pdf

73

Ken

Damon K9CQB
 

Ken, 
Thank you for spearheading this. I’ve built 3 of these and I just noticed a website that is selling both the kit ($69ea ) and the fully assembled version ($79ea), but the fully assembled version was bought out immediately. It will be in stock again in 2 weeks. Here is that website to purchase the kit or system: 

When combined with these $90 DMR amplifiers, you have a great 25-30W system:
AMP‑U25D - UHF (+DMR) Amplifier 400-480MHz, 20-40W Output 2-6W BTECH AMP T2 ($90)

I have not gotten my nodes installed yet. I am going to pair a Raspberry Pi with each of these modems to manage services. One of the slave models will also have a LoRa-mesh hat on it for future LoRa management connectivity. This node will also be connected to an AREDN 5GHz node. Here is a photo:



Damon Schaefer
K9CQB
iPhone: 1 (410) 961-1190
Secure Mobile: 1 (410) 514-0302

On Oct 28, 2019, at 10:42 AM, Ken Jamrogowicz via Groups.Io <ke2n@...> wrote:

Damon and I are planning to try out the NPR (UHF high speed packet) modems being called "New Packet Radio"  we have parts and some assembled boards.

https://hackaday.io/project/164092-npr-new-packet-radio

Recently, other projects have take my available spare time, but this is in the pipeline. 

As you probably know, UHF data rates are presently limited by some arcane FCC regulations that never anticipated that you might want to do anything faster than 56k data, even on a band where 6 MHz wide channels are already permitted (for ATV). The developer of this (NPR) system never wanted his system to go this *slow* but has come to realize that a lot of hams in the US would use it, if it were FCC-compliant.  In the future, if someone gets the FCC to move regulations forward, these units can run at much faster data rates just by setting configuration parameters.  

This is a master-slave system (managed TDMA). One way to make it run fast is to have the master node be full-duplex.

My plan is to set up a full-duplex node here - tentatively operating with 423.225 MHz input and 428.225 MHz output (out of consideration of the other repeaters at this site).  It would have an IP connection to the 2/5 GHz AREDN mesh at this location and basically serve as an extension of the NoVA AREDN network.  

How exactly one would use this is entirely something to be discovered.  For starters, would provide an IP connection suitable for messaging using the software already employed in packet (Winlink, etc).  Just faster. 
It should be accessible from anywhere that you can hit one of the W4BRM repeaters with an HT - tree blockage only having a minor effect at this frequency.  You could use it as a local extension of your end of the AREDN network too.

you can find more info and links on 
https://www.arednmesh.org/comment/13498#comment-13498
https://cdn.hackaday.io/files/1640927020512128/NPR_advanced_guide_v2.2.pdf

73

Ken