AN920

The Micromitter has flea power. Only -10dBm out of the chip. To get 1W you will need to amplify at least 40dB and deal with the resulting harmonics! :)

RF feedback is known to cause "hum". This is normally not a problem when the transmitter is mounted in a metal box and screened audio cables are used. Kits that comes with plastic boxes may have this problem.

Also there will be a problem to turn off the scr's when the count restarts.

I don't know about a single chip apart from a micro. Discrete it could be done with a row of D-type flip-flops wired as serial-in-serial-out (SISO) shift register and clocked by the 555. You may also use 2X 8bit shift register chips with the proper feedback after 10 stages.

Looks possible to do with only 1 comp and 1 opamp

Extra leg may also be for mechanical strength when mounted in a pcb and not connected to anything internally. Few simple measurements will be all that is needed to solve the mystery.

You used to get split capacitors (2 caps with one common neg terminal) used in older TV applications, although I have not seen them for quite some time.

Maybe we should define "very high frequency"

Here in the US it is quite common. You buy these inserts and install them into a normal light switch box. It has 3 positions; off-auto-on. The circuit has a sensor to sense movement inside the room and the whole thing costs about $6 and takes about 3 minutes to install.

There's LC filters of all kinds, low/high frequency and of various power levels. For example, you won't use toroid at very high frequencies because of the losses. Each applicarion will require its own selection.

Are the waves separate like on 2 inputs or combined at some point?

Will the phase shift always be the same or variable?

Souns like a easy task for a PIC micro. Look on the microchip website for typical counting applications and code to drive the displays. You will also find a lot on Google.

What I have done in the past is to wash equipment that had coffee, coke

http://www.anatekcorp.com/qdmmvom.htm

Often these TV's have a switching type PSU. They use a high value start-up resistor to get the PSU control circuit going. After that DC gets fed back through a diode blocking circuit to supply the control part of the PSU. Over time these resistors increase in value and have problems supplying enough DC to the control part to start the PSU quickly. Look for and measure all the 100k+ resistors (1/4-1W) that you can see in the PSU section. Example shows a starting resistor in a Sylvania TV's PSU

The document also states that the lowest fundamental crystal available is about 1kHz!

Low frequency crystals do exist and are used as shown in the table

Introduce some dead-time in your switching

That you can calculate from the well known formula wl=speed of wave/frequency wl = full wavelength in m speed = 3 X 10 ^8 m/s frequency of operation in Hz

sometimes it may be easier to wind some more turns in the opposite direction to subtract from the voltage.

Good point.

Shouldn't the ammeter be placed after point 3? That way all the current will go through the meter including transients from the output cap.

The RSSI (Received Signal Strength Indicator) is the output from a internal log detector

Good! I see you used an integrator to give you proportional voltage according to pulse width. Then it looks like you inverted this and scaled it with your last opamp. There are many ways to do this. Some methods will give you very good linearity and other not so well. It appears that you operate at low frequencies?