Hi Vic, Dave Ishmael has a single 813 amplifeir in this month's Electric Radio. Please do publish your amp for all of us to look at. I still have an 813 and socket I have had since I was a kid- maybe it's time to build an amp for my Atlas 350XL.
Dale W4OP ----- Original Message ----- From: "Vic K2VCO" <[email protected]> To: <[email protected]> Sent: Wednesday, December 22, 2010 11:14 AM Subject: Re: [Elecraft] 100 Watts or 500 Watts >I just finished building a grid-driven amplifier using two 813 tubes. With >a 3 db > attenuator at the input, it requires between 16 and 40 watts of drive on > 160 through 10 > meters respectively, for 800 watts output (only 700 on 10). Without the > attenuator, it > would need 8 - 20 watts drive. > > And this is a class-C amplifier designed for CW only! If it were a class B > or AB linear, > the drive requirement would be even lower. > > Grounded-grid is not the only way to design a tube amplifier. Although a > traditional > grid-driven circuit is a little more complicated, it's one way to get more > gain. > > I am going to put some pictures and schematics on my web site soon, not > that I think > anyone will want to duplicate it! > > On 12/22/2010 7:50 AM, Ron D'Eau Claire wrote: >> Even the Elecraft 100 watt amps are integrated with either the K2 or K3 >> control logic so they cannot be used as a stand-alone amplifier with >> other >> transmitters. >> >> The only reason I have ever seen from the FCC for the amplifier >> certification and 15 dB gain limitation is to discourage the CB >> 'bootleggers'. Certainly building a stable, clean amplifier that would >> take >> even a few milliwatts to 1000+ watts is a straightforward design >> exercise. >> There's no real problem with using more than one stage of gain if there >> was >> no 15 dB limit on the system gain. >> >> Ron AC7AC > > -- > Vic, K2VCO > Fresno CA > http://www.qsl.net/k2vco/ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.872 / Virus Database: 271.1.1/3331 - Release Date: 12/22/10 02:34:00 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
