I ran 304TLs in push-pull class C awhile back. Required a lot of drive Just about all the 32V3 could due. I ran 500V of Grid Leak Bias at about 160 ma of grid current for the pair. At 1KW DC input using 1700Volts on the plates I got a little over 800 Watts out to the dummy load.
I used 304THs for awhile in the circuit because of the much reduced drive requirements got a little less output, and a little more color on the plates but it modulated the same with good symmetry. Those are the only applications where I have compared the TL and TH. John -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of W2INR Sent: Saturday, February 23, 2008 3:16 PM To: [EMAIL PROTECTED]; Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] TH vs TL Make that bias voltages, from the specs it looks like the drive will be similar in Class C W2INR wrote: > The only differences will be drive and bias voltages. The performance > will be the same once dialed in. > > > > G > > Brett Gazdzinski wrote: >> I don't think you will see any difference at all. >> >> I used both as modulators, with the same results, and use 811 and 812 >> triodes in the push pull rig with the same results also. >> >> Theoretically, the higher bias tubes work better in class C >> but you cant hear or see any difference. >> >> Brett >> N2DTS >> >> ----- Original Message ----- From: "Barrie Smith" <[EMAIL PROTECTED]> >> To: "Discussion of AM Radio" <[email protected]> >> Sent: Saturday, February 23, 2008 1:41 PM >> Subject: [AMRadio] TH vs TL >> >> >> I'm curious as to the difference in RF performance between the TH (as >> in 250TH) and the TL (as in 250TL) versions of older triode tubes. >> >> Looking through the Eimac spec sheets for various old, glass triodes, >> the only real difference appears to be that the TL versions require >> higher grid bias in class C RF service. >> >> I've used the TH versions of several of the older tubes a good number >> of times over a many year period, but I've only used the TL types in >> modulator service. However, if there is no real difference in RF >> performance between the two in class C, I'm tempted to. >> >> 73, Barrie, W7ALW >> >> ______________________________________________________________ >> Our Main Website: http://www.amfone.net >> AMRadio mailing list >> Searchable Archives: >> http://www.mail-archive.com/[email protected]/ >> List Rules (must read!): http://w5ami.net/amradiofaq.html >> List Home: http://mailman.qth.net/mailman/listinfo/amradio >> 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. >> ______________________________________________________________ >> Our Main Website: http://www.amfone.net >> AMRadio mailing list >> Searchable Archives: >> http://www.mail-archive.com/[email protected]/ >> List Rules (must read!): http://w5ami.net/amradiofaq.html >> List Home: http://mailman.qth.net/mailman/listinfo/amradio >> 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. >> >> > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/[email protected]/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > 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. > > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio 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. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio 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.
