56KB modem EPROM for Atlanta LAN


File = 56KEC05A.BIN
This eprom image is for the Error Correcting Coded version of the WA4DSY 56kb modem. It is required to access the Atlanta area 56KB user LAN (44.36.16.**).

The binary data in 56KEC05A.BIN must be burned into a 27C256 EPROM with an access speed not slower than 150 ns.

NOTE: Be sure to turn dip switch #3 ON to enable ECC mode.

The following table list the modem IF frequencies available in the EPROM.

 Memory   TX Freq   RX Freq   RC Code   Tuneup Freq
 ______   _______   _______   _______   ___________
   0      29.050    29.050      20       29.050
   1      29.150    29.150      20       29.150
   2      28.400    29.850      20       29.850
   3      29.850    28.400      20       28.400
   4      28.550    29.550      20       29.550
   5      29.550    28.550      20       28.550
   6      29.250    29.250      20       29.250
   7      29.350    29.350      20       29.350
Notes:

Memory 1 is for the Lanier Mtn bit repeater on 440.150/445.150 using a 440 mhz transverter with 2 LOs. The LOs are switched between tx and rx for the 5 mhz split.

The 440 mhz transverter crystals are 104.000 mhz for receive and 102.750 mhz for transmit. These are 5th overtone series resonate crystals.

Memory 2 is for the Sweat Mtn. bit repeater on 222.400/223.850 using a 222 mhz transverter.

Download 56KEC05A.Zip (8.6k)