SCS DR-7400 Pactor P2P modem and SDR 1.9.13

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  • Updated 2 years ago

A years or so ago, I had my SCS DR-7400 modem working with SDR 1.5.1. I have not used it for a while and tried to get PACTOR P2P working for the COMMEX last weekend. TX timing and latency see to reared it's head in 1.9.13. Could to get a reliable sync either send or reciveing. Setup below:

DIGIU at 5K
Mike=ACC
EQ=off
PROC=off (Default on DIGIU)
DEXP=off (Default on DIGIU)
Set Comport you are using to Active in CAT

RMS Express:
TNC setup:
PSK=4000 (max)
FSK=4000 (max)
TX delay 0 to 20 tried 5 to 80 with no successful results.
Radio software 12.9.13
Radio - Flex 6500
Band USB DIGITAL

Computer direct hardwired to radio (no hub).

Does anyone have an idea? worked before! $1,500 modem should work with a $4,500 radio. Many of us in MARS and emergency services rely on  PACTOR and HF.

Thanks for any help!




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Kg5dwx

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Posted 2 years ago

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K6OZY, Elmer

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Hmm that looks proper, but you don't need to set it to 5K anymore.  You can dial in an exact 300/2700Hz filter, go into the Radio Setup -> Filters and uncheck "Auto" on Digital.  Set the filter slider to the far left (0) and the latency is very low.  I'll retest with my DR-7800.

Edit:  Wait, I don't see you settings AGC to OFF in that.  You need to have AGC set to OFF.
(Edited)
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Kg5dwx

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I an at 5k, I did set dig to low latency, unchecked. AGC is on...that could be it. I typically have ACG to medium and gain at 56. Where are you running your gain with AGC off? Thanks for your help!
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K6OZY, Elmer

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With AGC off, there is no specific setting.  It's based on band noise and signal strength.  The modem is pretty robust at a wide range of settings.  I usually make it "sound" as loud as it was with AGC enabled and adjust from there if needed.  If you have the dig filter set to 0, tighten that filter as you are unnecessarily killing your S/N with such a wide filter.
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Kg5dwx

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RGR, Ill try to do some test on Thursday.