The 5 calibers to claim the most powerful handgun in the world title reupload duration. Island amplifier usa was founded by john stanford, kf6i, in 2014. There are 3 resistors on the hv board that control the hv output to the. Alpha brought the amplifiers production and parts procurement back to the usa alpha 99, but the price rose reflecting those improvements. Converting the blow out prone pin diodes to vacuum relays. Alpha 76pac version, three tubes, hypersil transformer, is the top of the line in the 76 line. Other then that the amplifier is amazing, auto tuning, so many safety features its unreal. The original alpha design had the grid trigger flowing through the ptt line. The fan is quiet and the displays let you know what is going on. Complete warranty registration form and mail to eto at once. The first thing i noticed with the alpha is that the build quality of this amp is far better than the others i have owned. A few have heard of it, but have never seen one, even fewer own one.
The eto alpha 77dx is the quintessential 8877 amplifier, and is a work of art as well as a great performer. The weight of the alpha 76pa amp is quite substantial for the size of it. My uses are contesting and dxing especially on 160, 80 and 40. View online or download alpha power eto 91b user manual. The alpha 89 is easy to operate, but failure to carry out each procedure exactly as described in this manual is likely to lead to amplifier damage which is not covered under warranty. Eto 91b manuals manuals and user guides for eto 91b. If youre interested in utilizing this service contact us and well be happy to arrange an inspection for you. The amp will work great on the warc bands by choosing the next closest band on the band switch example choose 15 meters for 17 meters. View and download alpha power eto 91b user manual online.
However, i was also surprised to find the alpha amplifier had no built in protective circuitry except for excessive plate current. Ray heaton, long time employee of eto alpha, in the amateur amp section, was quoted as saying. Instant on all original except power supply has common electrolytic stack. Why alpha alpha power was founded more than a quarter century ago as eto ehrhorn technological operations to design and manufacture the best possible maximumlegalpower, continuous heavy duty, hf linear amplifier for radio amateurs. To aid in 87a fault diagnoses please follow software setup instructions before contacting alpha service, if at all possible. Details in the user manual tell how to configure the exciter and amp. I did encounter a problem with the amp where it was in fault 1 because of a resistor that was blown on the hv board. Sn 1012 12 with only about one dozen ever made on the same chassis as alpha 70v and alpha 77. The alpha 77 came next, built in the 70v cabinet, with the 8877 air cooled tube. Many hams have never heard of this particular model of eto alpha amplifier. In the troubleshooting section of the manual under 91b will not turn on.
Nice reprint of the original operations manual for this classic alpha amp. Protecting eto alpha 76a amplifiers after acquiring a used alpha 76a amplifier with 8874 tubes of unknown status, i was very pleased to discover the expensive 8874s were percolating well. I forgot about doing this and just recently found that resistor. The eto alpha 78 hf linear amplifier is an excellent choice for folks who are looking. Ameritron is a chevy while the alpha is the cadillac or rolls royce of amps. This is one of the most common problems with this amp and alpha knew it. Manual tune is smooth and reseting is easy with very fine graduated knob skirts. This is a short power out test with alpha 89 2 x 3cx800a7. The build and parts selection quality for 91b was inconsistent sometimes using cheap soviet surplus. Amplifier this technique should also apply to the alpha 99 and possibly acom amplifiers as well sovietmade gu74b tubes are readily available, but most were constructed sometime deep in the last century. The eto alpha 78 was designed at a time when the us federal communications commision fcc part 97 rules for amateur radio service rf power were specified. Service manuals, schematics, eproms for electrical technicians. Alpha 91b linear amplifier operation manual wclear plastic covers. I use the amp with the lp100 and so this sensor serves as a backup.
I am attempting to select between the alpha 89 and the alpha 91b and would appreciate the advice of the experts here assembled. I bought the alpha eto91b amp in 1996 and in 97 alpha sent me a resistor to change out. I need 91beta transformer transformer power 91b tpxx153 t1. It just sits there and makes buckets of power with little drive. We have 1 eto 91b manual available for free pdf download. It started out as the alpha 70v using the 3cv1500a7 vapor cooled tube, with ten air cooled amps 70a using the 3cxa7 tube being built. Alpha had acom building their manual tune amplifier alpha 91b in 1991 using a pair of 4cx800a7s. I have a alpha 87a its sn 99xxxxxx so it is one of the last ones made with all upgrades. Installation and operation 7 specifications, alpha 99 9 before installing your alpha 99 11 ac power source 12 antenna 12.
Email is not flawless and occasionally we cannot get a reply back to our customers. Keep the grid current as low as possible, and the tubes will last a very, very long time. Original problem was that the timer circuit did not time out and the wait light would not go off and pass into the ready mode. Only other modification is that i have added a fan that fits exactly to the airintake and pushes more ait into the box. Important precautions are given on pages 1 and 2 of this manual. Attention collectors very rare alpha 70v with air cooled 3cx in very good working condition. The amp s existing reflected power sensor is measured and that serves as an indirect way of sensing high swr. To open downloaded files you need acrobat reader or similar pdf reader program. Bilder manual pdf homepage personalia afulinks station. The alpha 91b is a great amplifier, i like it a lot. Alpha 91b sm service manual download, schematics, eeprom. My 91b shows 3kv on the hv meter, and perhaps older a86s do too, but this one is reading 1500v.
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