Sunday, February 28, 2021

using a mosfet for the output


Another option is the mosfet output. this one will need a volume control for sure.

Increased time line to 2 seconds.

 The 2 second sweep is not so smooth! Now the questions why and what to do about it.

Adding REAL world factors.

 The circuit was looking so good in sim. I built it and WOW! whiz, pop, motor boat, etc. 

The check center screen, start at 0 volts.

What happened?

Note: I also added the 2 ohm battery resistance.

Next extend the time line.

Adding an output amp for low Z.

 This simple addition will drive a low Z earbub well. 

My earbud is rated at 1ma so that should be plenty loud enough.

Looking at amplifier circuits in sim and in real world or how to make sims more real.

 This basic circuit would be good for a high Z headphone amp. 

I reloaded the LTSpice iv simulator with no additional lib. 

If you load spice iv you can follow the sims.

This one does not look bad BUT we will look closer latter.

Wednesday, February 24, 2021

More on IF transformers


This is what is inside the can. One core two pie wound coils. Not a very hobby friend device to build.

The brave at heart could do it like this 2 and 3 makes a coil former that can be 'jumble' wound. For a one off production this will work but the jumble wind is not reproducible. (It will need adjustment.)

You can design a single layer coil using this nemograph and a good wire chart.

such as this one.

One more found on the web put in a can and ready to use.

DIT built her own IF transformer


Tip of the hat kiddo.