tech99's latest activity

You can buy a portable compass/sundial here...

The "mirror drum" must be very perfect optically, difficult to achieve I think.

The initial beam from the laser must have finite diameter for it to work I think, that is why I suggested a first, round concave lens as...

I think you might use a Galilean telescope arrangement. First a concave lens to expand the beam diameter, followed by a large...

What caught me by surprise was that although the ship was stationary, the flow of the tidal stream caused suction.

It is incredibly interesting. I have plotted actual fields in this way using models. It looks rather as if your dipole is terminated in...

I have noticed the effect when sailing a little boat near a large tanker, which was anchored. As a fast tide was flowing between us, I...

I understand that for switched mode power supplies, the choke input filter is more possible because the frequency is high.

The choke input filter is an excellent circuit because it has good regulation under load and uses the transformer efficiently. With a...

I suspect the camera has an automatic exposure adjustment, so that the dynamic range can be accommodated, and which will prevent...

Also just to mention that silver compounds should not be put into the drainage system as it is very toxic to plants and animals.

In principle, the coil can be made to present an impedance of 50 Ohms resistive by using two capacitors. The actual loss resistance of...

The amplifier is able to operate into any load safely, and has ample power available, so i would try a direct connection first.

It seems that you have two in-phase sources of radiation spaced apart. So you have an array. The energy absent from the minima will be...

The radar cross section of a sphere is simply pi r^2, its cross sectional area. The energy hitting this area is then reflected...