¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. Linuxham
  2. Topics

Fldigi slow squelch response

 

I'm working on a laptop to laptop demo of Flmsg?+ Fldigi and I've got it mostly working using two USB sound cards in a crossover configuration.

Signal noise floor is about -80db and when I "transmit" it comes up to -20db. The waterfall looks clean and I do get a good copy... mostly.

I was having issues getting the complete message when I discovered that the signal on the squelch meter was coming up VERY slowly to the point of missing most of the message, especially using Flmsg where there are multiple transmissions.

I looked through the configuration but didn't see anything?that jumped out at me that would affect this.

I just booted up Fldigi on my desktop which is connected to my FT-991A and when I click on a PSK signal the squelch meter comes up pretty fast (but could probably be a little more aggressive now that I'm paying attention to this).

Any ideas?

All computers running on Fedora 41 with latest Fldigi.?

Thanks,
Richard
KF5OIM
 

which mode Richard ?


On Tue, May 6, 2025 at 3:25?PM Richard Shaw, KF5OIM via <hobbes1069=[email protected]> wrote:
I'm working on a laptop to laptop demo of Flmsg?+ Fldigi and I've got it mostly working using two USB sound cards in a crossover configuration.

Signal noise floor is about -80db and when I "transmit" it comes up to -20db. The waterfall looks clean and I do get a good copy... mostly.

I was having issues getting the complete message when I discovered that the signal on the squelch meter was coming up VERY slowly to the point of missing most of the message, especially using Flmsg where there are multiple transmissions.

I looked through the configuration but didn't see anything?that jumped out at me that would affect this.

I just booted up Fldigi on my desktop which is connected to my FT-991A and when I click on a PSK signal the squelch meter comes up pretty fast (but could probably be a little more aggressive now that I'm paying attention to this).

Any ideas?

All computers running on Fedora 41 with latest Fldigi.?

Thanks,
Richard
KF5OIM
 

On Tue, May 6, 2025 at 7:50?PM Dave, W1HKJ via <w1hkj25=[email protected]> wrote:
which mode Richard ?

I played around with different ones and it turns out that the squelch response for MT-63 1KS is pretty slow. It made the ARQ mode in Flmsg unusable.?

I was doing a demo for my local EMA volunteer group. I was able to get ARQ mode to work using PSK modes though.

Thanks,
Richard
KF5OIM
 

Try it with the squelch off, you may end up with a bunch of junk on the screen, but should not effect the reception and validation of checksum data. Kind of think the high latency of MT-XXXX modems might be the issue. I have not check or used FLARQ, wounder if there is a response timer that may be set to short for that modem.
Robert
 

On Wed, May 7, 2025 at 12:46?AM Robert, KK5VD via <kk5vd=[email protected]> wrote:
Try it with the squelch off, you may end up with a bunch of junk on the screen, but should not effect the reception and validation of checksum data. Kind of think the high latency of MT-XXXX modems might be the issue. I have not check or used FLARQ, wounder if there is a response timer that may be set to short for that modem.

I think that would be fine for the shoot and forget (Autosend) method, but my understanding is that if you're uring ARQ mode it will think the radio is "busy" and not go into transmit until it's not.

Thanks,
RIchard
KF5OIM?
 

The MT... modes were created well before the advent of the ARQ / AMP modes.? The largest MT user base were (and possibly still) the Military Affiliate Radio System, MARS.? The most effective modes for ARQ, FLMSG, FLAMP are MFSK and THOR.??

David

On Wed, May 7, 2025 at 6:32?AM Richard Shaw, KF5OIM via <hobbes1069=[email protected]> wrote:
On Wed, May 7, 2025 at 12:46?AM Robert, KK5VD via <kk5vd=[email protected]> wrote:
Try it with the squelch off, you may end up with a bunch of junk on the screen, but should not effect the reception and validation of checksum data. Kind of think the high latency of MT-XXXX modems might be the issue. I have not check or used FLARQ, wounder if there is a response timer that may be set to short for that modem.

I think that would be fine for the shoot and forget (Autosend) method, but my understanding is that if you're uring ARQ mode it will think the radio is "busy" and not go into transmit until it's not.

Thanks,
RIchard
KF5OIM?
 

What is your rig's AGC set to? Im curious if changing the setting go fast or off yields any better results.?
 

On Thu, May 8, 2025 at 10:05?AM Drew, KG7YSX via <drinella=[email protected]> wrote:
What is your rig's AGC set to? Im curious if changing the setting go fast or off yields any better results.?

In this case no rig. This was for demo purposes. I just used the sound card equivalent of a null modem connector (two USB sound cards cross wired). Pretty much ideal propagation situation :)

Thanks,
Richard
KF5OIM?
 

Ok try turning off the AGC on your laptops.?

1 - 9 of 9