Is anyone having trouble getting your Digital converter box to work with old sets?

[Phil Nelson]

What's in those attenutators, exactly, besides a potentiometer? I have a similar looking Radio Shack model. Got it at a garage sale for a nickel or something. Maybe it's defective. I tried it a couple of times, and it seemed to have a range between distorting the signal and really really really distorting the signal.

Back to tubejunke's question. I see no clear statement that any source works well on channels 3 and 4 and I will respectfully renew my advice to clean the blasted tuner already. Quick and easy. I could show a child how to do it. Costs about 3/8 of a cent. Can't hurt, and it just might help

Phil

[Old1625]

Because those whammy-boxes are made in China the quality control is apt to be suspect. I tried several converters, and then DVD recorder/players, then finally bought a digital-ready flat-screen which was finally rock-n-roll.

[martyfreeman]

Originally Posted by Phil Nelson

What's in those attenutators, exactly, besides a potentiometer? I have a similar looking Radio Shack model. Got it at a garage sale for a nickel or something. Maybe it's defective. I tried it a couple of times, and it seemed to have a range between distorting the signal and really really really distorting the signal.

Phil

If it is properly designed, a "T-pad". This is similar to the "L-pad" used for speaker-level volume controls but it has three ganged potentiometers instead of two.

The stem of the T is a potentiometer to ground and the arms go to source and load.

An L-pad presents a constant impedance to the source and variable to the load (assuming that the source and load impedance are correct).

A T-pad presents a constant impedance to both the source and load (with the same underlying assumption).

Switched attenuators are really stepped T-pads.