I am looking for a servo for a vintage electronics installation in a touring car. The BEC is 6v but only 1.0 amp. Most of the servos I have tried these days are causing brownouts, even with 2 or 3 amps, so I'm concerned with this 1.0a BEC. Is this due to digital designs? If I choose an analog servo will I be OK? This one is a shelf queen pretty much, so it doesn't need to have the latest and greatest.

A Futaba S3001 or S3003 is still to get and fits the time period

Digital uses upwards (and over) 4x the amperage of analog servos The S300x that Roelof recommended is a good choice.

That would explain a lot. Thanks

Brownouts are generally caused by not setting the end points correctly, are you doing this with the wheels on the ground or in the air?

If the problem persists after ensuring the EPA is properly set, also explore various frame rate settings with your radio, that can also cause brown outs.

As a last resort I would consider installing a UBEC to bypass the internal BEC, some have reported limited success with a glitch buster, but since a UBEC is about the same price, it would be a fool proof solution.