nickde
Member
I have built the "data dicer" designed by Eric Cottrell and I am running it with LTRdump.
It seems to be decoding intermittantly, everyonce and a while I will get a good LTR decode LCN and TGID. I am also getting some messages decoded with the neighbor frequency (passport ?). But most of the time when I am hearing activity on the channel there is either "unknow" messages with all zeros in the fields or nothing.
I have scoped thur the circuit and most of the time when there is no activity on the channel (I see discriminator "white noise" at the input to the data dicer) there is a constant square wave at the output (pin 14) of the comparator/rs-232 driver. The wave form seems to change when there is activity on the channel. The output level is just less then 5v (4.5) on the positive or negivite peaks (about 9 v pp). Is this enough output level? I am feeding the output of the slicer into the CTS input even though the diagram says "rs-232 data output" which I take to mean RD input.
I am thinking that I might need a level shifter to increase the level going into the com port.
I have tried the normal/invert and it seems to work best on the invert position. I think that I have good RF signal it is very clean at the input, when there is activity on the channel.
Thanks for any help or ideas.
Nickde
It seems to be decoding intermittantly, everyonce and a while I will get a good LTR decode LCN and TGID. I am also getting some messages decoded with the neighbor frequency (passport ?). But most of the time when I am hearing activity on the channel there is either "unknow" messages with all zeros in the fields or nothing.
I have scoped thur the circuit and most of the time when there is no activity on the channel (I see discriminator "white noise" at the input to the data dicer) there is a constant square wave at the output (pin 14) of the comparator/rs-232 driver. The wave form seems to change when there is activity on the channel. The output level is just less then 5v (4.5) on the positive or negivite peaks (about 9 v pp). Is this enough output level? I am feeding the output of the slicer into the CTS input even though the diagram says "rs-232 data output" which I take to mean RD input.
I am thinking that I might need a level shifter to increase the level going into the com port.
I have tried the normal/invert and it seems to work best on the invert position. I think that I have good RF signal it is very clean at the input, when there is activity on the channel.
Thanks for any help or ideas.
Nickde