A discriminator is the 'heart' of an FM receiver. After the discriminator, audio filters and amplifiers follow that may heavily distort a digital signal. If you want to decode and monitor digital (FSK and PSK) systems seriously, a discriminator tap is an absolute prerequisite. Only a few scanners have a discriminator output as a standard feature. In most cases, you need to 'operate' on your scanner to make the . This is the end of the installation portion of BCT discriminator tap. Post Production Notes. I used heat sink tubing to cover up the resistor and terminal solder connections. The 10k ohm resistor is to prevent harm to the main board if a short occurs. A capacitor is .
QRZ Forums. What exactually do you hear from a discriminator output. That's the first place the RF is converted into audio. Beyond that is audio amplification, squelch, etc. The discriminator output may also have a d-c level that indicates a mismatch between the incoming carrier frequency and what the receiver is tuned to, so it can drive a tuning meter, AFC circuit, etc.
K8ERVHow to qualify for low income 22, Last edited: Nov 22, K4USFNov 22, Instead, they often use a quadrature detector or a phase-locked loop.
Those types of demodulators are very easy to incorporate into a single integrated circuit. As ERV pointed out, a Foster-Seely discriminator has a DC voltage output that can be used to indicate a frequency discrijinator between the actual received signal and the center frequency of the receiver.
Also, using a calibrated oscilloscope the deviation of the received signal can also be read directly. Glen, K9STH. K9STHNov 22, K8JD discrmiinator, Nov 22, You hear thissssssssss. A true "discriminator output" tap is almost always DC-coupled without a blocking capacitor.
As such, be careful what you connect there. It won't drive a speaker or anything. This is a low level signal voltage only, no current available, thus no power available containing both a DC and an AC component.
I'm surprised the PC people haven't found a euphemism for discriminate. K8ERVNov 23, Show Ignored Content. Share This Page. Your discriminatr or email address: Password: Forgot your password? Register for a free QRZ account.
Oct 04, · A discriminator "tap" gives you access to the control channel data stream before it goes through the audio filters. That signal can be used by Trunker and other programs to read the info in the data stream and display it on your PC. It does NOT read MDT signals, most of . > discriminator tap on a PROAny help would be appreciated:) Pin 9 of IC2 or as I understand a good place is the test point TP2. Check out Bill Cheek's page. Jun 07, · Post. by simon26OD» 07 Jun , GBHgpJON wrote: Scuse me for asking buts what is a discriminator tap anyway. Well, to try and put it simply, it's the point in the receiver circuitry where the audio is extracted from the modulated carrier, before it is fed into the AF amplifier to drive the speaker.
Where's the best place to find info on the ic pinout for a discriminator tap on a PRO This file is for the benefit of all. This file can only be given away, absolutely free of charge.
Therefore, it is necessary to tap the "baseband audio" directly at the output of the discriminator chip for your scanner. The below Table shows a list of scanners, the discriminator chip s used in the scanner, circuit symbols of those chips, and three pins of general interest on the chips: RF-Input, Scan Control, and, of course, the baseband audio pin. Even though your scanner may not be listed, if you can find its discriminator chip, it will be listed with one or more scanners below, the pins of which will be the same for your unlisted scanner!
Corrections and additions to this list are requested. See my email and other addresses at the end of this file. Any help would be appreciated : Top 1. Spam Report. Red Wave Radio. Board index Radio Scanner. Any at all. Try and you will find it. Any help would be appreciated :. Yupiteru MVT discriminator tap 6. Xplorer Discriminator TAP? Discriminator Taps Discriminator tap for PRO Pro discriminator tap?
BC discriminator tap.