I recently bought a texas star 350 and a ranger 6900f25. The amp works well with my old uniden but if it's on hi and I key up with the ranger it locks up. (stays engaged after I let off the key) Only happens on high if on low or ssb it doesn't do it. Anyone have any ideas what could be causing this?

On another note both D-104 mics squeal when used with the amp no matter which radio I am on. Any ideas what I can do to stop this?

Thanks in advance for any help.