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Knight 600A tube tester - Printable Version

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Knight 600A tube tester - fields 100 - 05-23-2014

Hi,
I just got the meter and after pots and switches cleaning , replacing the cap and resoldering some joints it works fine (or may be it is just my wishful thinking). Fact is,I have a bunch of old tubes and for some reason they all show "good" between 80 and 90.Isn't it too good to be true? I follow all instruction and set the "U"and "D" switches correctly according to the chart as well as the load setting.
Also at the same time every tube shows "short" which they are not as I tried to put them in one of my working radios and they operate normally.Any ideas?
Thanks.

RE: Knight 600A tube tester - morzh - 05-23-2014

Let me guess....the tester is not working fine.

Get the sch, start checking the short path.
Also, get a know calibrated tube and a known bad (still functional) tube.
See what the tester will show.

RE: Knight 600A tube tester - fields 100 - 05-23-2014

That was a well educated guess.I sort of thought that someone having the similar unit have encountered the same problem and possibly will respond with the solution. No need any more. I am now on the market looking for the bad tube. Hoping to locate and obtain one. Wonder what should I spend for it.
BTW,I would not be able to change components and do resoldering without SCH.

RE: Knight 600A tube tester - morzh - 05-23-2014

Fields,

Tube testers electronics-wise are fairly simplistic. What makes them complcated is bunch of switches, but in Knight 600A there is only one rotation switch and bunch of on-off switches, so cannot be that complex.

A sch is always good to have but is not absolutely necessary. I am sure some folks here keep some weak tubes around and you probably coul have them for asking and possibly a shipping charge....

RE: Knight 600A tube tester - tab10672 - 05-24-2014

I have the same unit, are you checking the (#) beside tube settings? Every tube will show as shorted for that number switch indicated in parentheses.

RE: Knight 600A tube tester - fields 100 - 05-24-2014

@tab10672

Thanks for reply. The instruction does not mention parenthesis for shorts. It says that after setting the U,D and other switches according to the tube #, push any remaining switch up. If any of these switches will cause the neon to glow, the tube is shorted. As per instruction,the parenthesis's are for the gas check only.However, on my rolling chart (the tester came with 2, older and newer,I use older, for ##24, 27, 36, 37, 42, 80 tubes) there are no parenthesis's.
The tester came with a newer roller chart installed. The older one was loose in the box, and to fit it, I had to trim the wooden stick shorter. Is it possible it is from the different unit? It is printed "Knight" on it w/o model#.

RE: Knight 600A tube tester - tab10672 - 05-24-2014

   

RE: Knight 600A tube tester - tab10672 - 05-24-2014

   

RE: Knight 600A tube tester - tab10672 - 05-24-2014

#6 lever will show short on a 42 tube. Also, if the short lamp flashes it is just a cap in the unit discharging and should be ignored.

RE: Knight 600A tube tester - tab10672 - 05-24-2014

BAMA has every manual you need. Although they are for the 600, I have both and the only difference I have found is that the 600a tests some newer tubes but the old tube settings are the same. http://bama.edebris.com/download/knight/600tube/oldtubes/oldtubes6.pdf
http://bama.edebris.com/download/knight/600tube/tables/600tables.pdf

RE: Knight 600A tube tester - fields 100 - 05-24-2014

I may have to get different roller chart or the printout booklet. Your instruction is same as mine, the problem is, that my chart does not have those numbers in parenthesis. For the #42 tube, as an example, there is just a line between 42 and 4, whereas on yours you have the number (6). The tester came with different roller chart WITH the numbers in parenthesis,but there are no tube types I work with in there. The chart with my tube types was inside the box, loose. Could be from the different tester and the previous owner possibly used it just for the reference.
All the same, thanks for your help.

RE: Knight 600A tube tester - tab10672 - 05-24-2014

If you can't find a chart let me know, I hardly ever use this tester and have to track down the book (I have it somewhere) but I could scan it and email a copy to you. I have never had a tube that wasn't in either the book or the roll chart. I also have a loose roll chart I can scan. Keep in mind these are just emissions testers (go/no go) that will show a good tube but when under load the tube may show problems not found by the tester, after a few times of thinking the tubes were good and the radio still wouldn't work because of the knight I bought a Hickok.

RE: Knight 600A tube tester - fields 100 - 05-24-2014

Thanks so much for the offer. I just inquired on one on the E-bay, hopefully will succeed, otherwise will let you know.
Hickok is the next step, next so called bit of fun.

RE: Knight 600A tube tester - TomBoy - 10-14-2018

Hi, I have a Knight Tube Tester that does not have a model but looks like a 600 series. Many of the tubes that I need to test are not listed on the roll chart or in the supplemental chart PDFs that I have found on the web.  Does anyone know the proper tube setup for a 7591 tube? Is there a source for tube charts that cover some of the "newer" tube types?
Thanks.

RE: Knight 600A tube tester - frankking - 02-08-2021

Hi, my guess is that no one is reading this thread anymore but I will ask my question anyhow.  My 600A came to me in working condition and gives me believable results EXCEPT for the #3 switch.  When I push the #3 up I always get a full short... no matter what tube I am testing or where  I am on the rolodex.  Any ideas?  Thanks.