Subject: Re: Greetings

From: Rafael Diniz <[email-masked]>
Date: Fri, 13 Mar 2026 10:58:36 +0000

Hi John,

On 3/13/26 2:25 AM, John Goerzen wrote:
> 
> On Fri, Mar 13 2026, Rafael Diniz wrote:
> 
> [ some snips ]
> 
>>> If you do use nncp-daemon and nncp-call(er), you will want to set the
>>> NNCPDEADLINE environment variable, as well as the maxonlinetime and
>>> onlinedeadline to high values.
>>
>> Perfect - these are the details I needed to know, to start testing.
> 
> Looks like you've got a pretty nice protocol stack there.  Having a
> reliable stack underneath NNCP makes this all so much easier.
> 
> I thought I'd just send you a few more direct links on this:
> 
> https://nncp.mirrors.quux.org/Sync.html#index-NNCPDEADLINE talks about
> NNCPDEADLINE
> 
> https://nncp.mirrors.quux.org/CfgNeigh.html#CfgMaxOnlineTime covers the
> onlinedeadline and maxonlinetime settings.

Thanks, I'll read and try to set the configuration in two radio boxes on 
dummies next week.

> I am curious what over-the-air codec you're using.  Amateur packet radio
> over HF tends to use 300bps Bell 103.  This goes all the way back to
> 1963 and is pretty bad by modern standards, so I imagine you're using
> something better :-)

I hope it is better!
: )

At this point we are using these (de/)modulators from freedv:

| FreeDV Mode | RF bandwidth (Hz) | Payload data rate bits/s | Payload 
bytes/frame | FEC | Duration (sec) | MPP test | Use case |
| :-: | :-: | :-: | :-: | :-: | :-: | :-: | :-: |
| DATAC0 | 500 | 291 | 14 | (256,128) | 0.44 | 70/100 at 0dB | Reverse 
link ACK packets |
| DATAC1 | 1700 | 980 | 510 | (8192,4096) | 4.18 | 92/100 at 5dB | 
Forward link data (medium SNR) |
| DATAC3 | 500 | 321 | 126 | (2048,1024) | 3.19 | 74/100 at 0dB | 
Forward link data (low SNR) |
| DATAC4 | 250 | 87 | 56 | (1472,448) | 5.17 | 90/100 at -4dB | Forward 
link data (low SNR) |
| DATAC13 | 200 | 64 | 14 | (384,128) | 2.0 | 90/100 at -4dB | Reverse 
link ACK packets (low SNR) |
| DATAC14 | 250 | 58 | 3 | (112,56) | 0.69 | 90/100 at -2dB | Reverse 
link ACK packets (low SNR) |

Right now, DATAC13 for control plane, and DATAC4, DATAC3 and DATAC1 for 
the data plane, to be used by the gear-shift logic:
https://github.com/Rhizomatica/mercury/

> I'm also interested in what non-amateur bands you're using.

We always ask license channels in bands for fixed and mobile stations in 
HF, there are much more bands for fixed/mobile HF station for private 
use licensing than for Ham radio (the ITU frequency attribution have all 
the top-level details, and each country some specifics).

- Rafael