scratchy and crackly reception on some of my phones...

[302man]

Hi, I have some phones in my collection that have scratchy and crackly sounds when I pick up the receiver. It doesn't seem to matter when I replace the cord with a new one... I've tried replacement cloth ones and rubber-coated ones. It mostly is with my 202 and my 302, although I have an older 500 that does it too. My newer 500s are nice and clear. What else should I look for to troubleshoot? 

[MMikeJBenN27]

When you tried replacing the cords, do you mean the line cord, or the handset cord, and on the 202, the line cord that runs from the jack to the subset?

[Key2871]

Check the transmitter capsule. Try wiping the contacts down with rubbing alcohol, or lightly use an eraser.
Just to clean things.
If you still get some static. Tap the capsule on its edge turning the unit not hard, you just want to break up any clumping of the granuals.

[poplar1]

If you move the cords around, one at a time, the static will get noticeably worse when you shake the defective one.

If you have more than one 302, you can borrow a "known good" transmitter from a 302 that does not have static.

It is called isolating the problem or, as my 7th grafe teachet called it, the "process of elimination "

[RB]

You may have dirty hook switch contacts???

[countryman]

In most cases the transmitter is the culprit and will make crackling and other funny noises even when not moved. Tapping or shaking may give a short term improvement but not always.
Cord or contact issues may also occur though.