"Jay in the Mojave" wrote in message
...
Hello All:

Who remembers the Sonic Cushion, a 47 light bulb wired in series with a
speaker, and a low ohm pot. Mounted in a small square plastic box.

This circuit used the 47 light bulbs variable element resistance vs
variable current, as a sound cushion for SSB. Works prett good.

I have one wired in and think I have it right!?!?!?!?

Any web sites on this?

Jay in the Mojave

Hi Jay , yeah I remeber those as an automatic volume control. Boy that was
back in the 60's. I know I can date it back to between probably 67 and 69
when I first heard of it because I used one on my old Hallicrafter. The
Halicrafter had AVC but this worked better for keeping you from getting
blastedd by a strong signal that suddenly appeared when you had everything
cranked up to hear a weak signal. Bulb would have to be in series and
resistor in paralell because the bulbs resistance goes up whenever more
current flows through it. If it works it must be right.. That is to say I
dont remember either but I do remember it using two bulbs and the model I
built was to be used with headphones. You had to crank the volume on the
radio way up and then use a control on the box to adjust it to listenng
level.

Ok I found something that is just opposite what you wanted, I dont do ascii
drawings so I will have to discribe it to you.
Imagine a bridge circuit made of two #47 bulbs and two 5 ohms resistors.
They are wired so the resistors dont connet to each other and the bulbs dont
connect to each other but the bulbs do connect to the resistors. Input is
through a pair of opposite corners of the bridge and output is through the
other pair of opposite corners. At first I thought that you could reverse
the position of the resistors and diodes to get what you wanted but after
describing it I realized you would still have exactly the same circuit.
Cicuit is in CBers Handybook