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Post by markT on May 28, 2013 10:27:23 GMT -7
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Post by BritInvasion on May 28, 2013 11:17:01 GMT -7
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Post by randalp3000 on May 28, 2013 18:04:54 GMT -7
those might tell you if a tube works or not at low voltages but not much else. Here's a legit current production tube tester www.amplitrex.com/at1000.html
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Post by zpilot on May 29, 2013 0:54:50 GMT -7
I wonder whatever happened to all of those tube testers that used to be in every appliance and hardware store. Of course that was also back when my dad bought me my first .22 rifle in a toy store. Anyone else remember this?
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Post by Maddog on May 29, 2013 4:52:01 GMT -7
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Post by markT on May 29, 2013 4:58:27 GMT -7
those might tell you if a tube works or not at low voltages but not much else. Here's a legit current production tube tester www.amplitrex.com/at1000.htmlNow THAT is a modern day tube tester! Thanks Randy.
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Post by markT on May 29, 2013 4:59:41 GMT -7
I missed that one. Thanks Frank. Would like to hear Dr Z's opinion. Myles comment pretty much says it all.
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Post by Maddog on May 29, 2013 5:04:57 GMT -7
I bought this one off the bay yesterday. I will have to get it calibrated tho. There's just no cheap way out anymore. I used a Hickok 6000A exactly like this one for years working in my Dad's little radio station. So I do have a great level of comfort with this particular model. These work well (when calibrated) and give you a great deal of info about any tube.... www.ebay.com/itm/140984706228?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
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Post by markT on May 29, 2013 14:45:09 GMT -7
^^^ Nice find & unit Lee. Now the next big question, where to get it calibrated and how much does that cost??
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Post by doctorice on May 29, 2013 18:46:01 GMT -7
Good find, Lee. Here's a previous thread on the topic. Tube Testers
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Post by Maddog on May 29, 2013 19:38:55 GMT -7
^^^ Nice find & unit Lee. Now the next big question, where to get it calibrated and how much does that cost?? This is the cat right here: www.alltubetesters.com/and it'll cost about another $350.00..... Like I said, it's a pretty pricey proposition these days....
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Post by zpilot on May 30, 2013 6:01:44 GMT -7
Myles or the Dr. might want to chime in on this. For years I have only used my tester to see if tubes are "bad". Like most, it does not test at full plate voltage but it will show shorts and gas pretty well and give me some idea whether or not a preamp tube has adequate life left in it. At least I can sort those out.
I always buy power amp tubes in matched sets from reliable sources (never Ebay) so I don't test them. I guess I've been lucky because I've never had a bad one. I do test them "in circuit" after proper burn-in for balance and adjust or rearrange them if necessary. I don't care what a tester says. I can tell whether power tubes are getting tired after about three hours of use on stage. As a matter of routine I change "new manufactured" preamp tubes after about 200 hours. I never change NOS preamp tubes unless they quit working and they almost never do. In client's amps I always use new tubes because it just isn't worth the increased chance of something failing.
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Post by markT on May 30, 2013 11:30:14 GMT -7
Miles or the Dr. might want to chime in on this. For years I have only used my tester to see if tubes are "bad". Like most, it does not test at full plate voltage but it will show shorts and gas pretty well and give me some idea whether or not a preamp tube has adequate life left in it. At least I can sort those out. What kind of tester do you use??
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Post by zpilot on May 30, 2013 15:57:53 GMT -7
It's a Heathkit. I don't have it at the house right now and I don't remember the model number. The last few amps I've worked on I just pulled the tubes one at a time and placed them in a working amp to verify they functioned properly. I wasn't interested in troubleshooting the entire amp. Just finding what the problem was and fixing that.
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Post by zpilot on Jun 4, 2013 23:44:14 GMT -7
I looked at my tester today and it is a Heathkit TC-2. One of these days I'm going to upgrade to one that has more capabilities but I'm not going to pay a FleaBay inflated price to do it. Heck, at one time I thought I had to have an O-scope so I bought one and it's been years since I've used it. I can check just about anything on a tube amp with two good multi-meters and a capacitance tester. Oh, I also use my Mark 1 eyeballs and my ears too.
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Post by myles on Jun 10, 2013 9:14:10 GMT -7
Some folks wrote me about this around NAMM time and I gave them my take on it, cannot find what I wrote. In essence, without knowing the working voltages this does not impress me. It does not have a stout power supply so testing tubes for any sort of current capability is out of the question. It is too pricey in my opinion for a go nogo piece of gear. You'd be better off buying a tweed champ kit and using it as a tube tester. If sound comes out the tube works and if a tube is noisy or microphonic you could tell that as well.
Bottom line - this tells you, in a very expensive way, if a tube is burned out or not. I guess it tells you how it is burned out which is sort of pointless as it is after the fact not something like a gassy tube that may have a short life. It gives you no data so you cannot use it to check QA/QC of a tube maker or your vendor. You have no actual spec data to match, grade or measure tubes to compare to design spec. They supply some arbitrary data. In regard to power tubes you need a power supply capable of supplying high current and high voltage. Low plate voltage (Less than 250 volts) will yield results that are great for old radios but not for guitar amps. The internal power supply of this device is not capable supplying high voltage and high current.
Breaking down matching numbers to a 15 point scale is pretty crude. Not as crude as the ten point scale used in the past by GT and not nearly as useless as the low, medium, high scale used by Fender but pretty rough compared to folks that match within a milliamp or a few milliamps. As a side note, what is this rating based on? TC, plate current?
Bottom line .... I was not impressed when I looked into this during NAMM
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Post by markT on Jun 10, 2013 18:08:04 GMT -7
^^^ Thanks Myles.
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Post by zpilot on Jun 15, 2013 13:49:24 GMT -7
Well this thread has prompted me to get another tube tester so I found and bought a Heathkit TTA-1-1. It's in excellent shape but due to it's age I will need to replace electrolytic caps, some diodes and resistors that have drifted to insure it's accuracy. That's kinda why I got out of dealing with vintage amps. Here we go again.
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