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1 khz tone generator1/5/2024 play ( frequency, step_duration, amplitude ) while generator. log ( frequency_end, 10 ), num_frequencies ): print ( "Playing tone at Hz". Step_duration = 0.43 # Time (seconds) to play at each stepįor frequency in numpy. Num_frequencies = 200 # Number of frequencies in the sweepĪmplitude = 0.50 # Amplitude of the waveform Generator = ToneGenerator () frequency_start = 50 # Frequency to start the sweep fromįrequency_end = 10000 # Frequency to end the sweep at frames_per_buffer, stream_callback = self. samplerate, output = True, frames_per_buffer = self. streamOpen = False return False def play ( self, frequency, duration, amplitude ): self. is_active (): return True else : if self. paComplete ) def is_playing ( self ): if self. paContinue ) else : return ( None, pyaudio. frames_per_buffer return out def callback ( self, in_data, frame_count, time_info, status ): if self. frames_per_buffer - len ( tmp ))) else : xs = numpy. x_max : # We don't need a full buffer or audio so pad the end with 0's streamOpen = False def sinewave ( self ): if self. frames_per_buffer = frames_per_buffer self. Import numpy import pyaudio import math class ToneGenerator ( object ): def _init_ ( self, samplerate = 44100, frames_per_buffer = 4410 ): self. play ( frequency, duration, amplitude ) If you just need to play one particular frequency you can substitute the usage example for (remember to enter your own frequency, duration, and amplitude) generator = ToneGenerator () generator. It doesn’t create smooth waveform transitions between each frequency step so you’ll hear pops whenever the frequency changes. Sometimes it can take a while before it starts playing. On Ubuntu: sudo apt-get install python-pyaudio Make sure you’ve installed pyaudio to make this run. Every tape formula has a distinctive smell and some brands carry a distinctive family smell it's relatively easy to learn how to identify a tape formula by smell alone by storing a reel of tape in a plastic bag as well as the box and just just sniffing the bag storing the tape.This script generates a frequency sweep from 50 Hz to 10 kHz and is easily adjustable. Once you find a tape formulation you like, use it exclusively. wait until there's a minute or three of tape on the take up spool or hub, then start. Grab some tape before you attempt a bias setting ie don't use the tape at the start of the hub or reel. Ideally the playback will show the same Vu level as the record, but somewhat more important is the playback levels of the two tones relative to each other. Record the two bias setting tones at -20Vu (cassette) -10Vu (consumer tape deck) or 0Vu (professional tape deck). A 1 Khz tone can also be useful, however. 400 Hz is a good second tone, you only use the two. You can substitute 20 Khz if the machine uses at least 1/2" tape and you are recording at 30 ips. Stay tuned, if anything works I'll draw it up on that original thread.Īn upper limit for bias tone generator would be 10 Khz for any 1/4" tape machine or smaller (eg cassette 1/8"). I'm trying to fly the drill it yourself lexan board over the mcmelecttonics pcb, but holiday preparation has got in the way. I've got some new $.85 DIP project boards from mcmelectronics, the DIP socket fits and solders fine but there is no room on it for the 15 discrete parts involved. I have been trying to get it packaged with test circuit 12 on the datasheet () but I've mostly proved solder sticks better to drill it yourself lexan and beigh CB boards than it does to socket pins. You can still get the IC in DIP package for $6 at. The Exar XR2206 sine wave generator IC looks to be a lot more professional, but the nifty kit that was built on top of this is long gone. BTW, the power supplie I have dedicated to this is a 4 amp 12 V CT battery charger transformer on an open frame that produces 19.5 V full wave rectified (1500 uf cap) or 9.5 V half wave rectified (2200 uf cap) both using the minus rail as reference. The GE circuit is not producing any tone I can hear through the amp I'm trying to repair, that does play a transistor radio a bit into a speaker before motorboating. Don't know if the 6 mv was ~800 hz (with. Have tried both 2n2905 at reversed polarity, and 2n3904 with as drawn polarity so far, got 6 mv out a little while but the o-scope sweep quit, I guess it blew the power supply. I'm trying to build a 2 transistor oscillator from the GE Transistor manual 7th edition, it worked with a lot of hum imposed but when I put enough capacitance on the rail to get rid of the hum it just sits there. The EDN link for an amplitude stable oscillator leads to some op amp circuit using an op amp I don't have. Check out this link for a build it yourself: The Eliot project has way too many parts for my taste, a split supply which is another 6-9 parts, plus some weird light bulb I don't have as a PTC Resistor.
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