[WRAP:beg][WRAP:lf][WRAP:fn KC5GOI-20120108-164026Z-1.213]<flmsg>1.1.13
<ics213>
:to:18 DENTON CO ARES NET
:p1:7 NET MSG
:fm:6 KC5GOI
:p2:18 DENTON CO. ARES EC
:d1:10 2012-03-01
:t1:5 0045Z
:sb:22 DEMO MSG FOR THE GROUP
:mg:2033 THIS MESSAGE WAS GENERATED TO DEMO THE DIFFERENCE BETWEEN MT63-2K AND PSK-500R.

MT63

Protocol
These are unconnected, manually controlled message asynchronous symbol synchronous simplex chat modes, with full-time Forward Error Correction. The 64 PSK tones are spaced at 1/64th of the bandwidth, for example 15.625Hz for the default MT63-1000 (long) mode.

Operating Parameters

DUTY CYCLE IS 80% FOR ALL SPEEDS
Mode      Symbol Rate Typing Speed Bandwidth
                      CPS          Hz
MT63-500  5 baud      5.0          500
MT63-1000 10          10           1000 
MT63-2000 20          20           2000 

PSKR ("R" for "robust")

Using a similar design as the MFSK modes with a convolutional encoder and an interleaver these modes provide a much more robust link at the expense of the data speed which is divided by half when compared to the standard BPSK mode. Soft bits decoding was also added to maximize the probabilities of decoding the right sequence.

Coding and Character Set

The PSKR modes use binary convolution to generate two bits per varicode bit at the same symbol rate.  the number of interleavers for each baud rate is 40, 80 and 160 for PSK125R, PSK250R and PSK500R respectively.  PSKR modes use the MFSK varicode which provides a small increase in average speed of about 13%.

DUTY CYCLE IS 80% FOR ALL SPEEDS
Mode      Symbol Rate Typing Speed Bandwidth
                      CPS          Hz
PSK125R   125         22           250
PSK250R   250         44           500
PSK500R   500         88           1000

This message took the following time to send in each mode.

Mode     Time
PSK500R 
MT63-2k

PSK500R does not require as much transmit volume as MT63.

If you use either mode over a vhf repeater, you will need to insert enough time for the pl tone to allow the repeater to key up.  By using the parameter Pre-signal Tone under the id tab in Fldigi, you can insert the needed 500ms.  It is suggested that you use at least 200ms for simplex operations to allow both radios to open the squelch.
[WRAP:chksum B021][WRAP:end]