> > > Yes, but they're such a cute little toob. Actually I'm still > trying to > decide whether it will be the pair of 4-65s or a single 813.
The 813 will do 300 watts out at 2000 volts 200 ma all day long. They also work well at lower voltages. > > > If you were to build an RF deck that ran 3000 volts, its best to > > build a modulator that runs 3000 volts, otherwise the mod > transformer > > has a huge voltage difference between primary and secondary. > > > > In my (planned) dual 4-65 rig*, I will run a 2500V common supply for > both the 811 modulators and the RF PA. I've run 811s at 2500V before, > and as long as you don't exceed plate dissipation ratings, they seem > perfectly happy about it. I would use a pair of 100TH's or 100TL's rather than abuse 811's. The 100TH makes a good match for the 4-65, both are rated to 3000 volts. I would trade you some 100TH's for 811A's but I don't think tubes ship well, especially 100TH tubes. > > *Actually, I'm still trying to decide whether it will be the pair of > 4-65s or a single 813. >> You would need a multimatch mod transformer so you could > turn it around. > > > Or, if you do it that way, flip around the primary and secondary > (assuming the secondary has a center-tap). Or is that what > you mean by > "turn it around?" Yes. A regular mod trans usually does not have a tapped secondary. I know how it goes, sometimes you have to build a rig to use some really neat parts or tubes! Brett N2DTS ______________________________________________________________ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected] To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
