Hi all,

I am working on a way to produce short bursts at specific frequencies with a specific interval between bursts. I used one timer on a 556 dual timer to produce a 1 Hz clock pulse that is triggering a decade counter. When the counter overflows it sends a signal to trigger the second timer which is configured as a one shot to stay high for 8 ms or 17 ms depending on which RC combo I have switched into the circuit. I have that part working like a champ. What is need is some advice on the best way to use these high state intervals to switch a sine wave to an output. I am using a function generator produce the sine wave. I need to switch 150 kHz, 500 kHz, 1.4 MHz, and 30 MHz. Ultimately, this circuit will be used to test the channels on an old CISPR 14-1 discontinuous interference tester.

Thanks,

Bill B

 

What you want is called an analog switch. They come in many flavors. Go to a distributor website like Digi-Key to get example part numbers of those parts which are in stock. That should narrow the search pretty quickly.

 

The 30 MHz is going to be tough. The Vishay DG506 can probably do it if you follow it with a low input capacitance buffer.
www.vishay.com/docs/65150/dg506b.pd