mustang guy Posted January 31, 2014 Share Posted January 31, 2014 (edited) Hey all you tube-heads. I need to tap into your thermionic emissions. I need your biased opinion. I am going to take the plunge and purchase a tube tester. I am definitely going Hickok, but am a bit torn as to which is best for me. The models I am considering, in lowest to highest price order are: least expensive ($300 or so) Hickok 600 & 600a Hickok 800, 800a & 800k Hickok 6000, 6000a Hickok 533a Hickok 539a, b or c most expensive (into the thousands of $'s) I will be using the tester on my 4 tube tuners and 2 tube amps for now. I also have a bunch of tubes, including a pair of Mullard EL37's which still have very legible labeling, which I want to test. The tester will be a mainstay of my tube work, which is pretty basic right now, but growing weekly. I intend on making sure I buy a tester which has been calibrated or recently serviced. If I get something that hasn't been, I will be paying the extra money to have it sent off to a qualified Hickok technician. edit: I forgot that I also have a tube receiver. OMG, I have 7 peices of tube gear! I had none a year ago. Edited January 31, 2014 by mustang guy 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted January 31, 2014 Share Posted January 31, 2014 Look at the way I did, YOUR tube types, not 65 sockets you will never use. hickok is a great test unit. $300 to $450 tops, Ebay . Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 Here is a list of tubes I currently have in my equipment. Is there a quick way to see what the lowest common denominator tester is based on this list? 6267 12AT7 12AU7 12AX7 5V4 6AB4 6AL5 6AN8 6AQ8 6AU6 6AV6 6BA6 6BE6 6BH6 6BJ6 6BJ7 6BQ7A 6C4 6CB6 6CW4 6DJ8 6EA8 6U8 6V4 6X4 7189A EBF89 ECC85 EL37 EM840 EM84a KT66 PCC88 Thanks, Craig 2 Quote Link to comment Share on other sites More sharing options...
bracurrie Posted February 1, 2014 Share Posted February 1, 2014 I am going to take the plunge and purchase a tube tester.While I am not answering your question, I non the less wonder why buy a tester if you can get them tested by someone who already owns one. That's what I am doing. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 I live in Parkersburg, WV. There is only 1 person I know who owns one, and it hasn't been calibrated that he knows of. He is the ONLY electronics repair guy in my area. To add to that, I intend on utilizing the tester regularly. I am not just fixing up a few units I have. I am now a collector. 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted February 1, 2014 Share Posted February 1, 2014 Here is a list of tubes I currently have in my equipment. Is there a quick way to see what the lowest common denominator tester is based on this list? 6267 12AT7 12AU7 12AX7 5V4 6AB4 6AL5 6AN8 6AQ8 6AU6 6AV6 6BA6 6BE6 6BH6 6BJ6 6BJ7 6BQ7A 6C4 6CB6 6CW4 6DJ8 6EA8 6U8 6V4 6X4 7189A EBF89 ECC85 EL37 EM840 EM84a KT66 PCC88 Thanks, Craig I always ask the seller to supply the list, then have a beer and compare. start with the cheap one, work your way up till you find one that meets your needs, one thing I do is if its a small tube, I just buy 6 or 8, if I suspect its bad chuck it. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 One of my tuners has a number of questionable tubes. Also, I have a couple of EL37's which I think might test well. If so, they could be worth $150 a piece. They are carefully stored away until I can get confirmation. Just those two tubes could pay for my tester! 1 Quote Link to comment Share on other sites More sharing options...
Fjd Posted February 1, 2014 Share Posted February 1, 2014 Hey all you tube-heads. I need to tap into your thermionic emissions. I need your biased opinion. I am going to take the plunge and purchase a tube tester. I am definitely going Hickok, but am a bit torn as to which is best for me. The models I am considering, in lowest to highest price order are: least expensive ($300 or so) Hickok 600 & 600a Hickok 800, 800a & 800k Hickok 6000, 6000a Hickok 533a Hickok 539a, b or c most expensive (into the thousands of $'s) I will be using the tester on my 4 tube tuners and 2 tube amps for now. I also have a bunch of tubes, including a pair of Mullard EL37's which still have very legible labeling, which I want to test. The tester will be a mainstay of my tube work, which is pretty basic right now, but growing weekly. I intend on making sure I buy a tester which has been calibrated or recently serviced. If I get something that hasn't been, I will be paying the extra money to have it sent off to a qualified Hickok technician. edit: I forgot that I also have a tube receiver. OMG, I have 7 peices of tube gear! I had none a year ago. I use a Hickok 539b that was fully restored by Roger Kennedy as my main tester. The more I got sucked into this vortex of looking for unusual vintage tube gear and experimenting with DIY using tubes, I realized that I should be looking for a tester that could test a wide range of tubes, wanted something that gave more accurate mutual conductance (Gm) readings that meant fixed Gm ranges using a switch rather than a variable control, and wanted to at least try to somewhat accurately match power tubes, I narrowed down the list. The Hickok 539b (just restored a few months before I bought it) was the first to come available in the price ranges I had set. Sad story on why I got it as a brother of a friend fell ill with a stroke and was selling everything as he no longer could use anything and medical issues became more important. I also have a B&K 747b and a B&K 707 as quick back ups, and for tubes that 539b does not test, and an old military tester for the 300b tubes as the 539b cannot test them. I would suggest reading the following pages by Roger Kennedy and Kara Chaffee. Kara no longer services tube testers as of June 2013. I thought that Roger may have had a few health issues a while ago and I'm not sure what his status is these days. There are a couple of other reputable tube tester repair persons, but their names are escaping me right now. Roger's list of things to ask yourself and his views on various tube testers. http://www.alltubetesters.com/articles/tester_guide.htm Kara's views on various Hickok models. http://www.tubewizard.com/recommended_Hickok_testers.htm Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 (edited) There is a document I just read which shows results of various testers based on a 12ax7 tube. It seemed that the 600a was the most consistent performer across the many 600a units tested, and accuracy to the lab tester results (RCA WT100A). I found it facsinating that the 539 didn't fair well at all. Not only were there large inconsistencies between the 10 Hicock 539's tested, the mean micromhos was way off from that of the RCA lab unit. This makes me question readings people advertise on ebay for used tubes. The 539C results are regularly quoted in those auctions, and based on this document, they are inflated! I would much rather hear what a 600 or 6000 has to say about a tube! Go read this article. See if you come to the same conclusion. http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Roe-Pruefer/Hickock-539B/testing.pdf edit: fjd, I was typing when you posted. This post was in no way a slam on the 539's. Go look at the document and tell me what you think. Edited February 1, 2014 by mustang guy 2 Quote Link to comment Share on other sites More sharing options...
Fjd Posted February 1, 2014 Share Posted February 1, 2014 (edited) There is a document I just read which shows results of various testers based on a 12ax7 tube. It seemed that the 600a was the most consistent performer across the many 600a units tested, and accuracy to the lab tester results (RCA WT100A). I found it facsinating that the 539 didn't fair well at all. Not only were there large inconsistencies between the 10 Hicock 539's tested, the mean micromhos was way off from that of the RCA lab unit. This makes me question readings people advertise on ebay for used tubes. The 539C results are regularly quoted in those auctions, and based on this document, they are inflated! I would much rather hear what a 600 or 6000 has to say about a tube! Go read this article. See if you come to the same conclusion. http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Roe-Pruefer/Hickock-539B/testing.pdf edit: fjd, I was typing when you posted. This post was in no way a slam on the 539's. Go look at the document and tell me what you think. It wasn't taken that way. Actually, Chris Haedt was a well-respected tube tester repaiman, but I believe that he passed away early 2005. While I believe what Chris wrote is reputable, he didn't really state any of the testers were bad for their intended and designed use as service testers. He was hoping for more consistency between the same models and does offer up possible solutions. I suspect that these issues are what causes some of the dissagrements on eBay regarding tube sales. My suggestion is to keep researching and reading closely and try to validate what you read from another independent source that you can determine as reputable as you will discover much inconsistent information where it is difficult to know how to assess or what is true or skewed (most likely the information is so incomplete, it is difficult to interpret and compare to other sources). I've actually read that article in the past and understand most of what he says about the 539b/c, amongst many others with various observations, including many that talk about the most accurate test is under the conditions the tube will be used in (which will probably be way beyond my involvement or budget). Chris does go on to say that one of the more stable in relation to the 12AU7, the Hickok 600A, can differ between testers by more than 10% on high-current tubes. I found it interesting where he was showing how Gm changed by slight adjustements to the bias. One thing that intrigued me about the 539b/c models was that if a tube was not listed, a person could experiment with a known good tube and derive the settings. When you think about it, all of these testers that we are looking at were really designed for service work and the tolerances were not that tight new, let alone 30 or 40 years later when you are trying to calibrate while who knows how many parts have drifted from spec. Roger talks about the sevice testers with the variable control knobs that have an overall accuracy of +/- 15% which is essentially a 30% variance range from high to low (a tube which has a true Gm of 6000 could read a low of 5100 Gm to a high 6900 Gm (range of 1800 Gm), and would be within the accuracy range of the testers calibration standards. Really anything less than laboratory grade will only really give you varying levels of information related to a tube being 'good' or 'bad.' Here is another page on Roger Kennedy's pages that details the tight operating parameters the Hickok testers need to operate under and the solid state rectifier modification he uses to tighten up the specs. My Hickok has several of his upgrade options including the solid state rectifier. Actually my Hickok and B&K still will show different readings from each other (both articles mention various reasons for this), but I've not had one show a tube as bad and the other show it as good. Each tester is very consistent with repeatability of the test results that do not seem to drift. http://www.alltubetesters.com/articles/83_5y3_diode_pack.htm Actually, the first on my list was the triplet 3444A, then the Hickok 580 quasi-laboratory, Hickok 752A, then the Hickok 539b or 539c. If I had the budget, my first choice would have been an Amplitrex AT-1000. Edited February 1, 2014 by Fjd Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 There is a document I just read which shows results of various testers based on a 12ax7 tube. It seemed that the 600a was the most consistent performer across the many 600a units tested, and accuracy to the lab tester results (RCA WT100A). I found it facsinating that the 539 didn't fair well at all. Not only were there large inconsistencies between the 10 Hicock 539's tested, the mean micromhos was way off from that of the RCA lab unit. This makes me question readings people advertise on ebay for used tubes. The 539C results are regularly quoted in those auctions, and based on this document, they are inflated! I would much rather hear what a 600 or 6000 has to say about a tube! Go read this article. See if you come to the same conclusion. http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Roe-Pruefer/Hickock-539B/testing.pdf edit: fjd, I was typing when you posted. This post was in no way a slam on the 539's. Go look at the document and tell me what you think. It wasn't taken that way. Actually, Chris Haedt was a respected tube tester repaiman, but I believe that he passed away early 2005. My suggestion is to keep researching and reading closely and try to validate what you read from another independent source as you will discover much inconsistent information where it is difficult to know how to assess or what is true or skewed (most likely the information is so incomplete, it is difficult to interpret and compare to other sources). I've actually read that article in the past and understand most of what he says about the 539b/c, amongst many others with various observations, including many that talk about the most accurate test is under the conditions the tube will be used in (which will probably be way beyond my involvement or budget). Chris does go on to say that one of the more stable in relation to the 12AU7, the Hickok 600A, can differ between testers by more than 10% on high-current tubes. When you think about it, all of these testers that we are looking at were really designed for service work and the tolerances were not that tight new, let alone 30 or 40 years later. Roger talks about the sevice testers with the variable control knobs that have an overall accuracy of +/- 15% which is essentially a 30% variance range from high to low (a tube which has a true Gm of 6000 could read a low of 5100 Gm to a high 6900 Gm (range of 1800 Gm), and would be within the accuracy range of the testers calibration standards. Really anything less than laboratory grade will only really give you varying levels of information related to a tube being 'good' or 'bad.' Here is another page on Roger Kennedy's pages that details the tight operating parameters the Hickok testers need to operate under and the solid state rectifier modification he uses to tighten up the specs. My Hickok has several of his upgrade options including the solid state rectifier. Actually my Hickok and B&K still will show different readings from each other (both articles mention various reasons for this), but I've not had one show a tube as bad and the other show it as good. Each tester is very consistent with repeatability of the test results that do not seem to drift. http://www.alltubetesters.com/articles/83_5y3_diode_pack.htm Actually, the first on my list was the triplet 3444A, then the Hickok 580 quasi-laboratory, Hickok 752A, then the Hickok 539b or 539c. If I had the budget, my first choice would have been an Amplitrex AT-1000. The cost of the Amplitrex is high at $2,675, indeed. However, it is new, warranted, accurate by modern standards, and interfaces via USB to your computer. I like those things. I also like that it is solid state. If I were considering the flawless 539c on ebay at $3,500, I would buy the Amplitrex in a blink. I just read an article concerning the differences in results in auto-bias, and fixed bias testing on the AT1000. Amazing how big a difference testing at higher plate voltages, perhaps the voltage you will be using the tube in, can make the difference in a above average tube and a rejected tube. Here is the article; "Interpreting Amplitrex AT1000 tube tester results". If I decide to buy an AT1000, I will have to sell something. Let me see... ummm... thinking... drawing a big blank... I do have some KPT gear I could sell, but I'm not sure what I can get. Here is the list: 2 x KPT-684's - new $1500 each 3 x KPT-904LF's - new $616 each 8 x KPT-200's - new est $350 each cost new over $7500. Gotta be worth $2800 or so! Added benefit, I don't have stacks of huge speakers taking up my whole shop. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 1, 2014 Share Posted February 1, 2014 Looks like a good time to re-post a thread I started a while ago: https://community.klipsch.com/index.php?/topic/146633-is-tube-matching-with-a-tube-tester-a-waste-of-time/ Worrying about testing the tubes in a tuner which is working fine is a waste of time. Most of those tubes work well into the 15-20,000 hour range assuming you aren't cooking them by keeping the tuners inside a poorly ventilated, overheated, cabinet. Sure, if the tuner is exhibiting symptoms like poor sensitivity a swap of the RF or IF amplifier tubes is worth trying. But, just because a tester says a tube is good doesn't mean that it will work well in a particular unit. I've experienced many hundreds of tubes over the years which tested incredibly but worked poorly in some units and amazingly in others. This was very common in televisions as well. If you're concerned, I'd just buy a few of each type if the price is right and if you run into a performance issue, simply try a replacement. If it fixes the situation, there's no need to go further regardless of what a tester says. Maynard Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 2, 2014 Author Share Posted February 2, 2014 (edited) Looks like a good time to re-post a thread I started a while ago: https://community.klipsch.com/index.php?/topic/146633-is-tube-matching-with-a-tube-tester-a-waste-of-time/ Worrying about testing the tubes in a tuner which is working fine is a waste of time. Most of those tubes work well into the 15-20,000 hour range assuming you aren't cooking them by keeping the tuners inside a poorly ventilated, overheated, cabinet. Sure, if the tuner is exhibiting symptoms like poor sensitivity a swap of the RF or IF amplifier tubes is worth trying. But, just because a tester says a tube is good doesn't mean that it will work well in a particular unit. I've experienced many hundreds of tubes over the years which tested incredibly but worked poorly in some units and amazingly in others. This was very common in televisions as well. If you're concerned, I'd just buy a few of each type if the price is right and if you run into a performance issue, simply try a replacement. If it fixes the situation, there's no need to go further regardless of what a tester says. Maynard Maynard! I almost missed your post. The forum scrolls away so quickly... I was hoping you would comment. I definitely know you are biased to not spend the money on a tester. I hear what you are saying. I have a tuner, a receiver and 2 amps that need nothing (except a pair of 12ax7's in the tuner). There is the matter of the very nice looking Mullard EL37's I have which I want to sell, so I need numbers. I have 2 tuners that need some tubes, I believe. Caps and resistors test out OK on both. On one of them I barely get sound in FM, but the AM is strong. It seems to tune well in FM, just very faint. The other tuner has an issue of a pop sound every now and then. It's probably about 120hz, and sounds sort of like a bad place in an LP, but it comes and goes. I think there is a tube dying. Since these tuners have a total of 20 different tubes, I would rather get a tester to know what to shop for. I could just buy 25 new tubes, and sell the EL37's as-is, but that would probably cost me more than a Hickok 600 or 6000, and it still might not fix the problem. I hear what you are saying, but I don't think tube testers are bunk just because some tubes test well and occasionally don't work in certain equipment. On the other hand, your comments do make me reflect on how much I should be spending. I think minermark is right on his valuation. Edited February 2, 2014 by mustang guy Quote Link to comment Share on other sites More sharing options...
minermark Posted February 2, 2014 Share Posted February 2, 2014 Now im looking for one, I loaned mine to a bud in a ham radio shop that caught fire last week, and he called today, affirming the death of my old school tube tester. He was asking me replacement cost for his insurance, so ill be shopping on Ebay here in a few min. Dam, that was a good old tester too....... Quote Link to comment Share on other sites More sharing options...
thebes Posted February 2, 2014 Share Posted February 2, 2014 PM Speakerfritz. He had 3 testers of one brand whose name I can't remember that er reasonably priced but did mutual conductance in addition to gm. He'll advise you as to model, cost etc. Quote Link to comment Share on other sites More sharing options...
minermark Posted February 2, 2014 Share Posted February 2, 2014 I been shopping Ebay on and off all day, watching three at the moment. This just happened to bring back a lot of memorys of my dad dropping me off at thrifty drug on Saturday with a bag full of tubes, he would come back a hour later and id have checked and rechecked 20 tubes ! his for TV and mine for radio(s). Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 2, 2014 Share Posted February 2, 2014 Maynard! I almost missed your post. The forum scrolls away so quickly... I was hoping you would comment. I definitely know you are biased to not spend the money on a tester. I have 2 tuners that need some tubes, I believe. Caps and resistors test out OK on both. On one of them I barely get sound in FM, but the AM is strong. It seems to tune well in FM, just very faint. The other tuner has an issue of a pop sound every now and then. It's probably about 120hz, and sounds sort of like a bad place in an LP, but it comes and goes. I think there is a tube dying. Since these tuners have a total of 20 different tubes, I would rather get a tester to know what to shop for. I could just buy 25 new tubes, and sell the EL37's as-is, but that would probably cost me more than a Hickok 600 or 6000, and it still might not fix the problem. I hear what you are saying, but I don't think tube testers are bunk just because some tubes test well and occasionally don't work in certain equipment. On the other hand, your comments do make me reflect on how much I should be spending. I think minermark is right on his valuation. From the standpoint of resale, a tube tester can be of some value since so many rely on the numbers to decide if a tube is worth purchasing. Of course, that tells nothing about how noisy or microphonic a tube may be. Some sellers and dealers make a very specific comment about those points and refuse to warrant against those issues. As far as your tuners go, the one with poor FM sensitivity could have a bad IF or RF transformer. This is a problem frequently encountered in tuners and receivers. The popping sound in the other tuner may be a tube, capacitor, resistor, IF/RF transformer, solder joint, and so on. Intermittent problems can be very frustrating to pin down, obviously. It may be possible, if it's due to a resistor/capacitor, to find the culprit using a can of component "freeze." But, even that can be misleading. Sometimes one has to force the intermittent to become consistent by "cooking" the equipment- i.e. turning it on and placing a box over it for a few hours to trap the heat in the hope that the cause will manifest long enough to be diagnosed. It's not the greatest procedure, but it does work in some stubborn cases. Maynard 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted February 2, 2014 Share Posted February 2, 2014 looking/shopping for a new tube tester, I cannot believe what I came across, I grew up in Newport/costa mesa Calif, every local electronic store and employee knew my name, I was the kid that bought any/every dam thing that caught my eye, surplus aerospace was my Fav. Ebay, MarVac Electronics costa mesa, the same dam tube tester that I have hour(s) using as a kid, is for sale. Im thinkin about it, and thinkin. what are the odds of this happening ? Quote Link to comment Share on other sites More sharing options...
minermark Posted February 2, 2014 Share Posted February 2, 2014 (edited) looking/shopping for a new tube tester, I cannot believe what I came across, I grew up in Newport/costa mesa Calif, every local electronic store and employee knew my name, I was the kid that bought any/every dam thing that caught my eye, surplus aerospace was my Fav. Ebay, MarVac Electronics costa mesa, the same dam tube tester that I have hour(s) using as a kid, is for sale. Im thinkin about it, and thinkin. what are the odds of this happening ? Well that took almost 3 min to think about, Bought that bad boy! , I better take the wife to breakfast, bar & Grill is in order........ Edited February 2, 2014 by minermark Quote Link to comment Share on other sites More sharing options...
Fjd Posted February 2, 2014 Share Posted February 2, 2014 (edited) The cost of the Amplitrex is high at $2,675, indeed. However, it is new, warranted, accurate by modern standards, and interfaces via USB to your computer. I like those things. I also like that it is solid state. If I were considering the flawless 539c on ebay at $3,500, I would buy the Amplitrex in a blink. I just read an article concerning the differences in results in auto-bias, and fixed bias testing on the AT1000. Amazing how big a difference testing at higher plate voltages, perhaps the voltage you will be using the tube in, can make the difference in a above average tube and a rejected tube. Here is the article; "Interpreting Amplitrex AT1000 tube tester results". If I decide to buy an AT1000, I will have to sell something. Let me see... ummm... thinking... drawing a big blank... I do have some KPT gear I could sell, but I'm not sure what I can get. Here is the list: 2 x KPT-684's - new $1500 each 3 x KPT-904LF's - new $616 each 8 x KPT-200's - new est $350 each cost new over $7500. Gotta be worth $2800 or so! Added benefit, I don't have stacks of huge speakers taking up my whole shop. It has been a couple of years now since I closely watched the Hickock 539b/c prices. I had tracked them for close to a year; however, the range of "completed sales" I saw was from about $450 - $1,500. The high end of that range seemed to be pristine examples that in most instances were bought by people overseas (many times Japan or Korea); however, since then eBay has made it more difficult to determine where an item might have been sold. The highest I saw an item sell in the U.S. was right around $1,000 for very nice and most of the time very nice or recently calibrated (by one of the better known technicians) examples. I was targeting $600 - $800 in that range, then I bought mine for $850 (detailed above), but I did find a couple of extremely nice examples afterward on eBay for friends for $650 (almost mint but not calibrated) and $800 (calibrated). When I bought my B&K, I had seen very nice examples in the $200 - $400 range. Many times you can find a nice, calibrated B&K 707 or 747 for under $400. Research and patience will be your best friends. I found Kara's tips to buying on eBay interesting and considered those tips in each of my buying decisions. Here is a link to Nick de Smith's site with an update to Daniel Schoo's (another of Dan's papers is the subject of tube fanatic's linked thread) document on calibrating a Hickok 539B/C tube tester (published in 2007 on AudioXpress). The last few pages contain notes on the testers including a few of the quirks. http://www.desmith.net/NMdS/Electronics/Hickok_539C_Calibration.html http://www.desmith.net/NMdS/Electronics/Hickok/Hickok%20539C%20Calibration%20V4.1.pdf Edited February 2, 2014 by Fjd Quote Link to comment Share on other sites More sharing options...
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