RMS Express SmartSDR Latency

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  • Updated 5 years ago
I have RMS Express loaded and communicating with my 6500 and SmartSDR using Winmor 2K.  A dedicated CAT port is configured in Smart CAT.  The radio is in DIGU mode with AGC off.  Unfortunately no stations are responding to the radio.  The T>R latency is indicating between 300 and 400 ms.  Any idea from the experts what the problem might be?  I have reviewed the posts in this community and the online help and believe that I have set everything up correctly.

Thanks, Ron
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Posted 5 years ago

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Alex - DH2ID, Elmer

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Ron, a long latency period is normal for a SDR.
My WinMOR setup, which works with boxes in Europe follows.
I have set the session bandwidth to 1600 and left drive level at 100.

Radio settings:

Your CAT and PTT ports may vary.

The sound card tnc shows 372ms latency:

The 6500 is set to DIGU - 5.0K - FAST - DAX1.

This setup works, but I use PACTOR for EMCOMM with
a FT-897D or FT-857D, where latency is abt. 10 ms.

Alex DH2ID
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Al K0VM, Elmer

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   I will confirm that this latency is normal for the DSP in the 6500..  RMS Express/WImor will tolerate up to 1000 msec latency but it does reduce the through put a somewhat...   I would guess that the  DSP latency in the 6500 might be able to be tuned for ARQ applications, but I would not hold my breath.

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Thanks for the assistance,

I got the system up and working.  My connection attempts to 80M/40M RMS Winmor sites seem unreliable, but that may be due to my limited Carolina Windom antenna.  I am still getting a handle on how strong the signal must be relative to other digital modes such as RTTY and PSK31.

Connections to 20M RMS sites seem more reliable, but obviously very slow.  I would hate to send long emails using HF Winmore, much less attachments.

Thanks again,