Posted: 9/8/2013 5:32:06 PM EDT
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I was very close to dropping some coin on a GRE PSE500 but with all that happened decided to wait. This isn't about GRE though.
I just got 3 scanners all radio shack. 1.3GHz, dual trunking, race scanner. I'm not sure of the model numbers yet. The price was right so I didn't do much research before hand. I have noticed a lot of talk about discriminator tap mods. Why would one want to tap the discriminator? |
Discriminator tap is used for digital decoding software. I tapped the discriminator on my older RS Pro-2055 and used some software to try and decode the digitally encrypted traffic here...no joy. I didn't spend alot of time with it though. I don't even remember what software I was using.
The output of the discriminator is unfiltered, full range audio so it's not limited by the audio amp passband which the digital signal has a hard time getting through. |
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Quoted:
Why would one want to tap the discriminator? my wife absolutely hates it when i call her "the discriminator". 
ps in general, access to the discriminator circuit allows unfiltered/unprocessed access to the received baseband signal. by doing so effects of passband filtering, and so on, are avoided. one might do this to receive a signal with a wider bandwidth than the the radio was designed for in the first place. for example -- in the good ol' days of packet radio, 9600baud TNC's typically required tapping into the discriminator for the purpose of receiving 9600baud transmissions, which were not only wide bandwidth but also had keying phase relationships which perhaps the AF filters in the latter stages of the receiver were not so kind to. some modern FM radios such as the FT8800 even provide factory built-in direct access to the discriminator -- on the FT8800 it is the 9600baud data pin on the rear panel DIN connector. using this pin you can connect to an external decoder of your choosing (such as AIS or NAC, for example, for trunking). ar-jedi |
