While looking through some of the old cb/amp manuals I've collected through out the years I came across a pride dx 300 owners manual. It says when tunning for ssb operation to use a steady tone in ssb mode to tune. I own and use a few different old tube amps and when tunning them for ssb I just load them up on am then switch to ssb. My amp manuals say this is the correct way to tune for ssb on my particular amps. What tone is the pride dx 300 manual referring too and is this the only way to tune a pride dx 300 for ssb use. I don't own a pride dx 300 but I'm thinking about purchesing one. the thought of spending more money on sweep tubes than the amps worth makes me cringe. A single 250b between $100 and $150 seems a much better choice. Thx.