My beloved Heathkit SB-200 Linear Amplifier developed an intermittent problem that finally became permanent.  For the last couple months, I would notice a strange light "sizzle" sound coming from it after a warm up period.  This could be heard as a sizzling static in the reciever of my ts-570 as well.  It only lasted a few seconds at a time and only showed up on occasions every few days.  Finally, a visual inspection found some of the filter capacitors were "swollen".  It still had the original powersupply so I decided to use this as an opportunity to upgrade to the Harbach powersupply board and also install a Harbach soft-start while at it.

Well all went well and the amp has new lilfe now.  I had a set of Shuguang 572B's that I ordered as a spare set directly from China.  While I had the amp opened up I decided to rotate these in and give my Sylvania 572B's (made in USA) a break.  WHOA!  Those chinese tubes graphite anodes glow bright red in less than a minute with 130 watts carrier from AM or in about 3 minutes from 600 watts pep on sideband.  The Sylvanias barely blush at all ever.  That is scarey!  I don't want those tubes taking out other parts of my amp so I put them back on the shelf.  Be careful with Chinese tubes out there everyone!  Something is amiss with those!

73 for now, de KX5JT John -- God Bless

Hi John, did a search for TS-570 along with SB-200 and BAM, there you were. ;) I have just started using a SB-200 with my TS-570D(g) yesterday.... piddled around a bit on 75 and 40m. The rigs internal really doesn't seem to like the SB-200 being in line...... at all...... I was just wondering what you do to keep your pair playing nicely together. Oh, I am using an old Versatuner V between the SB-200 and the antennas and I do have a little 941e that I could put in line between the 570 and 200 if need be, but, I figured I would hit the old internet just to see if anyone may have answers and as you were on the top of the Google list.... I figured I would just pester the daylights out of you first. :)
very 73 de Tom ~ WV6Z