I have an old pride 500 amp That uses 4x2879 transistors. It is showing a dead short when i turn it on, swr between radio and amp goes to infinity. If i turn it off everything is fine. It has on the back of it 12-80 meter i had been using it on hf and it worked good with 30-40 watts drive would do about 500 watts. My question is who can fix the short problem and check the input and output tuning? I don't know anyone around here that can tune an amp. Do you fellows Know anybody with a good reputation who may be able to help me out. Thanks in advance
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Looking for a good tech.
- Thread starter KJ4BAE
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BOOTY MONSTER
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YouTube - CBRadioChat.com speaks with AMPOWER!
i know id want to trust my equipment to a drunk ........................
i know id want to trust my equipment to a drunk ........................
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BOOTY MONSTER
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contact this guy and see if he can help .
http://www.worldwidedx.com/amplifiers/59097-texas-star-amp-repair-free-help.html
http://www.worldwidedx.com/amplifiers/59097-texas-star-amp-repair-free-help.html
You're probably better off posting some clear pictures of the inside and having some of us point out likely problems. For example this is probably not blown output transistors. It's something on the input side. Without seeing the amp I would suspect an open resistor feeding RF into the amp. If it has a high low power switch or variable, that's where to look. The next likely problem would be an open relay contact or shorted padder capacitor.
Before I would bring a piece of equipment to someone for repair, I would have to be confident they understood what each components purpose was inside. For example, a factory authorized service center. While it may not be practical to quiz your tech, you'll find that most who work on 11 meter amps do not have a deep grasp of how each component works. But then again this is not required to change "pills" or copy another amp.
Toll_Free
Well-Known Member
Depending on the age of the unit (if it's a REAL Pride or not), will be telling on where the reverse polarity diode is.
I'd almost be willing to bet the RP diode is shorted. It's common, although not as common in linears as it is with radios.... I do still see them come in that way.
2879s and other "pills" generally blow open, not shorted.
If the thing is showing a short on the RP diode, I'd expect it to also be blowing fuses. If it's not blowing fuses, it's not shorted by a high current device... Probably a RX or switching transistor.
Look for a barrel looking device, leads out both ends. MIGHT have the words 1Nxxxx readable on it. Clip one side of it (or desolder, if you're handy with an iron). See if the short goes away. Money says it probably will. If it DOES, go grab another diode from the electronics shop (if you don't have one, go to the auto electric / alternator / motor rewinder... They have them for the trio in the alternators, and they work GREAT) and solder it in.
--Toll_Free
I'd almost be willing to bet the RP diode is shorted. It's common, although not as common in linears as it is with radios.... I do still see them come in that way.
2879s and other "pills" generally blow open, not shorted.
If the thing is showing a short on the RP diode, I'd expect it to also be blowing fuses. If it's not blowing fuses, it's not shorted by a high current device... Probably a RX or switching transistor.
Look for a barrel looking device, leads out both ends. MIGHT have the words 1Nxxxx readable on it. Clip one side of it (or desolder, if you're handy with an iron). See if the short goes away. Money says it probably will. If it DOES, go grab another diode from the electronics shop (if you don't have one, go to the auto electric / alternator / motor rewinder... They have them for the trio in the alternators, and they work GREAT) and solder it in.
--Toll_Free