Amateur Radio Digital Voice - WinDRM 21-Oct-05 release

WinDRM is the free PC software that allows you to transmit and receive digital voice using a standard SSB HF transceiver. A new version of this innovative program has just been released and can be downloaded from http://n1su.us/windrm

WinDRM 21-Oct-05 Release
Notes updated 21-Oct-05 by N1SU

This version incorporates the new MELP audio protocol. Tests seem to show that increased bitrates (Mode A, 64QAM, MSC Low Protection, or just click the Speed button and select 64QAM) yield better audio quality approaching
the quality of the AOR modems.

Under PTT port you will see new options for "PTT on CTS"
and "PTT on DSR". These are intended to control image transmissions as inputs for your mic PTT switch.

Also changed are the TX defaults (2.3 to 2.5 and Mode B to A). Download at:
http://n1su.us/windrm/windrm-21-oct-05.zip

Requires the MELP DLL to run - download at:
http://www.rarewares.org/files/others/melp_dll.zip and extract the contents into your WINDRM folder or wherever you installed WinDRM.

Remember, you cannot have any speech processing, audio shaping or ALC - speech processing and ALC action drops your received SNR considerably.

Adjust your linear amplifier to have extra loading - adjust the LOAD control so that the plates unmesh - so that at max power your output drops just slightly when adjusting LOAD. This helps increase linearity (or so i've been told and it does seem to help and i'm just imagining things).

73 Jason N1SU
http://n1su.us/

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