Platemodulated rf power amplifier class c telephony. His designs are showcased by the well known wavac audio labs. The aa8v 6ag7 amplifier schematic diagrams and circuit. My main reason is to introduce myself to you before the etf2008 which i hope to join. A grounded grid amplifier works on the basis of the grid being grounded for rf. For class c operation, it can be used, but not for any of the linear modes. Only the ameritron al811h gives you four fully neutralized 811a transmitting tubes. The chart frame on the top of the powersupply housing holds the clear plastic through which the voltmeter can be read. The first 70 years of vacuum tubethermionic valve audio amplifiers. My main reason is to introduce myself to you before the etf2008 which i. An ancillary board for setting individual transmit audio levels for each channel is mounted and includes six 10k ohm trimpots and miscellaneous parts.
Note that all these links are external and we cannot provide support on the circuits or offer any guarantees to their accuracy. Pdf nl811a nl811a nl811a tube 811a 811a ci 7400 power amplifier watts rms 811a tube nl811 class b push pull power amplifier 811a audio amplifier 6 watts resistor. The 811a vacuum tube it is a power triode capable to output 10 15 watts in a single. You do not use grid leak bias for a linear amplifier. To open downloaded files you need acrobat reader or similar pdf reader program. As with most transmitting triodes 3c24, 808, 811, you will need to operate them in class a2 mode meaning the grid is always positive. Free diagrams, schematics and service manuals with manufacturer name beginning with a. An 811a 200watt groundedgrid linear amplifier the amplifier shown in figs. The main category is amateur linear amplifiers that is about hf amplifiers for ham radio use. Highmu power triode for use in class ab2, class b, class c rf, and audio amplifiers.
A high power grounded grid amplifier and power supply. Ombura project report submitted in partial fulfillment of the requirement for the award for the degree of bachelor of science in electrical and electronics engineering of the university of nairobi 2016. It was quite popular to play with valves such as 811, 812 and other class b triodes. Vacuum tubes like pcl82, pcl84, pcl85, pcl86, ecl82, ecl84 or ecl86 can be used.
Single 811a gg amp for 20mtrs antique radio forums. The power output is just as good as an advertised ham amp tube. If establishment brand names such as audio research, conradjohnson, and jadis may be viewed as the dominant but plodding empire, then wavac strikes back with a powerful vision of what listening pleasure is all about. These have been in continuous production since the second world war and even saw service in desert storm. The excellent averaging time of the increased thermal mass through old 811a anode uchannels is mostly lost in the new 811a tube. Lower impedance and 100 % negative feedback of cf circuit lead to be strong in stability and. First schematic below is the original, the second is my adaptation for mono band 20mtr only operation. Here are some interesting schematics for the 811a tube. The aa8v 6ag7 amplifier schematic diagrams and circuit descriptions. The 811a tubes are long life, reliable transmitting tubes. Marcellino, w3bym 806 parkland drive, rockville, md 20853 this project began in the summer of 1981 at a hamfest held at.
Choseal la5101 6n occ audiophile hifi speaker cable 24k goldplated banana plug 2. Many hams like the challenging of hunting for parts to build a high quality amplifier out of inexpensive surplus parts. You might want to start with something similar to this. National nl 811a september 1992 page 1 the nl 811a is a threeelectrode tube designed for, the nl811a has a. The 6sl7 is a notorious poor driver and the voltage scheme for the entire amplifier is not optimal. It is a compact size transmitting tube, easy to designing and constructing for audio amp.
Ameritron hf power amplifiers are the most popular hf amplifiers in the world. Since september 2008 ive been working in a new project regarding a single ended triode tube power amp using the 811a vacuum tube. Service manuals, schematics, eproms for electrical technicians. Their high power vacuum tube linear amplifiers and solid state no tune amplifiers will take your hf operations to the next level. Antique radio forums view topic single 811a gg amp for 20mtrs. Singleended triode amplifier using zerobias transmitting tubes. Ameritron mounts the 811a tubes vertically not horizontally to prevent hot tube elements from sagging and shorting out. I have used 2 of these music tubes in my al811 amp with good results for the past 6 months. The amplifier is designed around the much improved 811a valve. Yes, it may have a few volts of bias on it, but if you want any amplification out of it, the bias needs to be fixed and only a few volts. Nos tube specification sheet nos tube specification sheet. Remove the foam packing material around the tubes that secures the 811a tubes during. A compact highpower linear four 811a qst june 1961, pp.
About 811 linear amplifier project the resource is currently listed in in a single category. Free diagrams, schematics, service manuals beginning with a. Actually it is a project with a long process of experimentation. Rf unit this is a conventional high q, pi tank design which gives good. When the amplifier is keyed up and tuned for full power, the. This power supply project can supply power to any one channel audio power amplifier project presented in this website. Audio power amplifier circuit diagrams circuit schematics. The shishido wavac 811a tube amp schematic in the photo above, the kairo modified schematic and gantis schematic in the photos below. Singleended triode amplifiers using zerobias transmitting tubes by michimori hirokuni. Full line of parts, service, and repair by designer at ctr engineering, inc.
Matched pair psvane 811a vacuum tube for medical amplifier. Some circuits would be illegal to operate in most countries and others are dangerous to construct and should not be attempted by the inexperienced. If the amplifier includes gas protection tubes on the filaments, the gas tubes may fire during the. This link is listed in our web site directory since tuesday apr 10 2007, and till today ameritron al811 manual has been followed for a total of 7610 times. I removed 2 of the 811a and tried them in the yaesu and amp and it had good output. How to build the dx811a allband linear amplifier cq magazine september 1982 by f.
National nl 811a september 1992 page 1 the nl 811a is a threeelectrode tube designed for, the nl811a has a maximum plate dissipation of 65 watts icas. In this amplifier the bias is chosen so that the amplifier requires the. View and download ameritron al84 instruction manual online. The complete receive audio board that takes output from the detector and boosts it to up to 6 watts out into the 4 ohm speaker is. Feb 14, 2005 hi group, i want to build a 10 40 meter linear amp. About ameritron al811 manual the resource is currently listed in in 2 categories. They contain preamplifier triode and power pentode in one tube. Carefully lift the amplifier by the bottom cabinet edge out of the shipping carton. It would be great if someone had the schematics and would be willing to email them to me. A real 811a transmitting tube will not operate in the referenced schematic.
Singleended triode amplifiers using zerobias transmitting tubes. For convenience and compact ness, the amplifier is completely selfcontained. Features four vertically mounted 811a valves class ab2 grounded grid excellent imd products softstart circuit variable threshold level type alc circuit matches modern hf equipment introduction the ranger 811h linear amplifier is a high powered grounded grid linear with a tuned cathode input circuit. How to build the dx 811a allband linear amplifier cq magazine september 1982 by f. If establishment brand names such as audio research, conradjohnson, and jadis may be viewed as the dominant but plodding empire, then wavac strikes back with a powerful vision of.
Al811h linear amplifier features the al811h is a grounded grid linear amplifier developed by ameritron using low cost 811a power triodes. Rick i have been working on old yaesu fl2000b amp it had low output and i purchased a al811h amp the yaesu uses 2 572b tubes which are a hd version of the 811a. The older al811h prior to drive resistor modification with good tubes and stable power line, when properly tuned and operating in the linear region, has about 11 db. The main category is ameritron al811 and al811h hf amateur radio rf power amplifier that is about ameritron al811 and al811h resources. The ameritron al811h is an economical 800 watt pep output linear amplifier that operates reliably from 160 through15 meters. The revenge kr842vhd amplifier lundahl transformers. Ameritron hf power amplifiers al811 free shipping on. Tubes such as the 811a, a zero bias power triode, have to be operated. The image below is of an 811a power triode from my collection. Hi group, i want to build a 10 40 meter linear amp. Recent listings manufacturer directory get instant insight into any electronic component.
The svetlana 572b may be operated with its axis vertical and the base down, or horizontally with pins 1 and 4 in a vertical plane. Srpp6n2p, cathode follower1721ma 6p3s, 811a 380v pout 15w in chan. At first i built a prototype amp using the sv81 tube. Taylor tubes is the preferred choice for fl2100, sb200sb201, 10160l, 30l1, etc. Useful power output, approximate 75% circuit efficiency.
Btw, the fullwave bridge rectifier is one i pulled from an industrial hv supply. How to build the dx811a allband linear amplifier cq. Due to the shipping complexity of this item an additional shipping charge will be added when shipped. The envelope, anode, and filament are identical to the 811 tube. If no bias is used, the resting plate current will be 150 ma for the four tubes. Averaged over any audiofrequency cycle of sinewave form. The 811a tubes take approximately 10 seconds to warmup. Direct heated triode power output tubes are really interesting. The vertical fin is now made from a single tall fold in each anode face.
Afterwards i built another one using the 811a tube. Versions of the 572b designed for audio amplifier service are available. The 811a used here is not to be confused with the svetlana sv811 audio tubes. Base indexed and internal structure aligned and supported for. Stereo vacuum tube audio amplifier this simple stereo vacuum tube amplifier is using ecl parallel or pcl serial tubes. Ameritron al811h linear amplifier 4 x 811a tubes hf 800 watts pep. Ganti 811a tube amplifier service manual download, schematics. A highpower groundedgrid amplifier and power supply fig. Place the amplifier on a firm, level surface and carefully inspect it for shipping damage. This link is listed in our web site directory since wednesday nov 14 2012, and till today 811 linear amplifier project has been followed for a total of 1464 times. Ameritron leads the industry with timetested designs that offer the best value for amateur radio operators and hf experimenters everywhere. The older al811h prior to drive resistor modification with good tubes and stable power line, when properly tuned and operating in the linear region, has about 11 db gain. You get absolute stability and superb performance on higher bands that cant be matched by unneutralized tubes.
Introduction the ranger 811h linear amplifier is a high powered grounded. I have no copy of the schematic for the 1916 version available at the time of writing. Everybody in the audio tube business knows that the justly famous brand names. A community dedicated to helping everyone learn the art of audio.
Vacuum tube 811a, triode, power amplifier, united states. This site helps you to save the earth from electronic waste. Free diagrams, schematics, service manuals beginning with. Abb goerz, abc radiocostruzioni, abi electronics, accuphase, accurate, ace. Main page and exterior photos tank coil construction details interior photos of the finished amplifier schematic diagrams and circuit descriptions construction photos. This circuit comes out of the mid to later 60s arrl handbook.