My pair of 813's loaf along at 700 watts of carrier out, unfortunately the antenna tuner does not.
I don't know what the pep would be, the power meter only goes up to 2000 watts and I have to guess by how hard it gets pinned. That's plate modulated service, as an AM amplifier I would not run it over 100 watts carrier. The 32V3 would put out the same power so that's a silly idea. For a reasonable boost, you need a LARGE amp with a LARGE power supply, running at least a pair of 3-500z tubes, run off 220 volts, then you can get 350 watts of carrier I think, which is the legal limit if modulated correctly. Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of John E. > Coleman (ARS WA5BXO) > Sent: Monday, April 23, 2007 11:04 AM > To: 'Discussion of AM Radio in the Amateur Service' > Subject: RE: [AMRadio] My Amplifer Quest took a strange turn today > > Bow: > You need to start over if you want to get 600 watts > carrier output. > A pair of 813s is just not capable of doing this in linear AM > service. 150 > to 200 watts is about it. And you don't have enough power > supply either for > large AM service. Keep in mind that to get a carrier of 600 > watts on AM you > must have an amplifier capable of over 2400 watts (4 X > carrier). Even so > there is another draw back in that when a linier amplifier is > operated at > full drive and full output (lets say 2500 watts) its > efficiency is 60-75 > percent and with no input its efficiency is Zero percent. > With this in mind > you can figure that at 25% of the full drive power and > output, that the > efficiency will be between 0 and 70 percent and in most cases > it is around > 25-30 percent. This means that the amp can produce a lot > more heat when > driven at 25% of full output than it does at full output. Hence the > probability of damage to light weight part is great. > > There are some rules of thumb to be used for linear amplifiers in AM > service, and these rules are a lot different in requirements for big > equipment than the rules of thumb for SSB service. > > This is the reason that many times it is better to use class C plate > modulated service instead. > > You have some parts there that could be very usefull and the > 813s or capable > of all you want and more, in class C service > > I would be happy to help with some graphs and drawing to get > you started if > you want to come by for so coffee. > > The Computer Fixer > 1622 Sawdust Rd. Ste A1 > The Woodlands, TX 77380 > 281-367-6765 > > PS: bring Chocolate Chip cookies > > > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Bow > Sent: Monday, April 23, 2007 2:39 AM > To: 'Discussion of AM Radio in the Amateur Service'; Glowbugs > Subject: RE: [AMRadio] My Amplifer Quest took a strange turn today > > Well, A bit of an update on my new toy.. > > I tested it today, after repairing some solder joints that > were not up to my > specs and replacing some wire I didn't like that looks of. > > The test was: > Icom IC-718 --> MFJ-949E antenna tuner-->Amplifier-->Daiwa 3kw watt > meter-->MFJ legal limit dummy load. > > The IC-718 will do 100 Watts on CW/SSB/Rtty and 40 watts on AM > > I used the frequency of 3870 kHz > > I first used a RTTY signal > Input from Rig - Output from Amp - Grid Current (amps) - Plate Current > (amps) > 30 - 180 - .02 - .24 > 50 - 380 - .07 - .34 > 60 - 400 - 0.1 - .36 > 75 - 410 - 0.2 - 0.4 > > Next I tried an unmodulated AM carrier > > 25 - 200 - .04 - .26 > 40 - 375 - 0.1 - .34 > > Final Check was on SSB, modulated to the peak ALC setting > with a 1 kHz tone. > 30 - 110 - .02 - .16 > 40 - 200 - .02 - .18 > 50 - 210 - .02 - .22 > 60 - 300 - .04 - .22 > 70 - 375 - .04 - .24 > 80 - 400 - .06 - .26 > > I figured 80 watts was about as hard as I want to drive it. > I don't have a High Voltage test lead here to actually check the plate > voltage, but I am going to take this featherweight (NOT!!!) > into work with > me and check it out there. > > Here are some more photos, including the guts. I may just > rewire this thing > for my own piece of mind. > > http://riley-music.com/BowsStuff/AMP/14Guts.JPG > > http://riley-music.com/BowsStuff/AMP/15TubeSockets.JPG > > http://riley-music.com/BowsStuff/AMP/16Relay.JPG > > http://riley-music.com/BowsStuff/AMP/17PWRSection.JPG > > http://riley-music.com/BowsStuff/AMP/18MeterSwitch.JPG > > http://riley-music.com/BowsStuff/AMP/19CapChoke.JPG > > http://riley-music.com/BowsStuff/AMP/20FilTranny.JPG > > http://riley-music.com/BowsStuff/AMP/21PWRTranny.JPG > > http://riley-music.com/BowsStuff/AMP/22CoilSwch.JPG > > I guess now I need to figure out how to do a few things.... > Get an opinion > from someone who knows something about amplifiers and homebrewing.... > 1. Make it band switch able for 80/40/20/10 > 2. Figure out a tuned input for the above bands > 3. figure out how to get it up to a 600 watt output level > (because everyone > tells me the first 600 watts are the best for signal boost) > > > Bow > > W5EFR > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 269.5.7/771 - Release > Date: 4/21/2007 > 11:56 > > > ______________________________________________________________ > 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. > > > ______________________________________________________________ > 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. > ______________________________________________________________ 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.
