I just bought a dozen servos (I'll leave the brand out of it) and in a trial noticed they emit a high pitched squeal, interrupted but not consistent interruption, and sound a little like morse code.

There is no chatter in the servo itself but if I push against the arm whilst activating it, the squeal gets louder.

These are metal gear servos, and were a good deal so I'm reluctant to either take them back or pitch them. I think they were probably made in China, but aren;t most modeling things these days?

Does anybody have any ideas or advice on these?

I appreciate your help.

G'day Mate,
They sound like digital servos, if they don't make a noise, when nothing connected to em, & make a sort of squeeling noise when touched, they are more than likely Digital. The noise is normal.
If that is the case use them & see how you like them, but be aware they will use more power to drive them, so your batteries need to be checked, often.