Discriminator Tap? What is it?

[safetyobc]

What is a discriminator tap. I see on the equipment wanted / for sale pages people asking for this. What are they talking about. Thanks in advance for any info.

 

[crayon]

The discriminator is also refered to as baseband audio.

It is the unfiltered audio signal just recovered from the air via the antenna of a radio. People use the baseband audio or a discriminator tap by feeding it into a computer to "decode" data communications because it is unfiltered.

HTH's

 

[loumaag]

As crayon indicates, this is the baseband audio taken from the FM Discriminator in the radio so it is unaffected by the audio stages of the radio. The reason you see it mentioned so much is that this baseband audio is what is required to feed software programs like Trunker, ETrunker, etc. Just another part of the hobby.

 

[INDY72]

NOTE: Tapping requires soldering wiring to very tiny points inside your scanner/reciever....

Unless A- You have a very steady hand, or B- You have a LOT of patience... I would NOT advise attempting to do a DT.

DT's are good for many reasons.

Running Trunker, eTrunk, T4Win, etc....

Running an secondary device so that you can run LTRDump/LTRTrunk. *This btw is the only way to "trunk track" Passport LTR.*

And for studying the base signal with various devices such as osciloscopes. Decoding digital audio.

Etc...

 

[crayon]

... this is the baseband audio taken from the FM Discriminator in the radio so it is unaffected by the audio stages of the radio.

Right.

I might also add that one can tap the AM Discriminator as well. In fact, this is perfered for monitoring ACARS transmissions.

 

[loumaag]

I might also add that one can tap the AM Discriminator as well. In fact, this is perfered for monitoring ACARS transmissions.

Good point, but it is really the demodulator as opposed to the discriminator. :wink: