Trial Update to the V4 TNC uploaded to Yahoo FTP
I am on vacation for a few more days. Did some work here the other day when it was too hot to do anyting else! I have uploaded a trial patch for the V4 TNC (Filename V4 TNC Patch 0.3.0.1.zip ). It contains a new TNC version which should be better in terms of sensitivity and symbol sync. I don't have my HF channel simulator here in the RV but it appears to be significantly better using an audio test with very low levels and noise. When I get home I'll run additional tests and tweaks using the HF simulator but some may want to try it now. This updated also includes an automatic calculation for timing during the initial ARQ connection. This should now automatically handle both fast turnaround and slow turnaround setups (slow computers etc). This also uses a mechanism to insure a CQ call does not recognize an inadvertent ACK.
This new version 0.3.0.1 should be compatible with the prior 0.3.0.0 version but should perform better. Try playing some with the squelch setting though 5 should be a good starting point and should work for all but the weakest signals.
What I am most interested in is:
Is this new version more sensive in detecting and syncing signals?
Is the ARQ mechanism working OK and useful on poor signals?
To use this new version simply download the zip file. Unzip and repace the V4TNC.exe file in your V4Chat directory. Keep (rename) your current V4TNC.exe file if you want to go back. You do not need to do an uninstall/re install. Simply replace your V4TNC.exe with the one in the zip. The revision history summarizes what changed.
Your comments welcome. Good luck.
Rick Muething, KN6KB
V4 TNC Revision History
Date Rev # Summary ofChanges
June 20, 2011 0.3.0.1
Add blnARQCQ to block inadvertent ACK while calling CQ
Add function AcquireSymbolSync to V4Demod to use FSF filtered values to determine sync (more accuracy)
Modify function SearchForAMLeader47B2 to only do Tone search and call AcquireSymbolSync only when Threshold criterial are met.
Added variable intMeasuredPTToffToACKDelay to calculate actual ACK Delay in ARQ mode. Modify intARQSpacing based on the measured intMeasuredPTToffToACKDelay value.