Sal Brisindi said:
I have a very nice Hickok 539B just like the nice sample Sal has posted. I've had it for 20yrs and in that time it has needed nothing. Just works...
I'm putting together a test set for testing 211/845 and might make something semi-permanent once I figure out what works.
I've always wanted an Audiomatica Sophia or a Tek 570, but I don't expect to run across either any time soon.. And I doubt I could afford either if I did... 🙄
I have a well-used TV-7/A that my father gave me. Painted black on the outside, lots of dents and the "acorn" socket is cracked.
He was visiting an old family friend who happened to be cleaning out his garage. Said he had an old tester. My father remembered my "eccentric" hobby and took it with him.
One of the best Christmas gifts I ever received.
He was visiting an old family friend who happened to be cleaning out his garage. Said he had an old tester. My father remembered my "eccentric" hobby and took it with him.
One of the best Christmas gifts I ever received.
There is a TEK curve tracer floating around our lab at work. I hide it whenever there is talk of cleaning up the lab since I have seen far newer and nicer test equipment crushed! Sooner or later its time will be up. They used to sell the old stuff to employees, but not anymore. Yes, I have "curved" a few tubes late at night.
I am planning to make my own once I get past the Visual basic - USB roadblock. So far it has me stopped dead.
I've got a hickok 533A. Seems very reliable and if it says the tube is good, it sounds good in circuit.
I was very lucky to "steal" it off Epay about 4 years ago for about $200.
It had a worn socket, so I fastened in a socket saver and all is well.
I was very lucky to "steal" it off Epay about 4 years ago for about $200.
It had a worn socket, so I fastened in a socket saver and all is well.
Hi folks , i am newbe here but veteran at other forums in the us.
I have a simple queston on Eico (635) testers:
When you use a EL34 (6CA7) to test which is brandnew, how far should the needle go on the 0-100 scale ? (50 starts as Good)
I would say 100 , but does any technicall eico user with experience have an answer ?
The new EL34 would be say 95 mA currentdraw at -13.5 volt bias and 250 volt plates.
Thanks !
PS they test for emmission right ? meaning platecurrent + gridcurrent ?
PS 2 does anyone have the operating manual ?
thanks again 🙂
I have a simple queston on Eico (635) testers:
When you use a EL34 (6CA7) to test which is brandnew, how far should the needle go on the 0-100 scale ? (50 starts as Good)
I would say 100 , but does any technicall eico user with experience have an answer ?
The new EL34 would be say 95 mA currentdraw at -13.5 volt bias and 250 volt plates.
Thanks !
PS they test for emmission right ? meaning platecurrent + gridcurrent ?
PS 2 does anyone have the operating manual ?
thanks again 🙂
Correct me if I am wrong but couldn't one just bias up the tube at a reasable point for that tube, measure Vg and Ik at two different points and calculate gm with a pocket calculator? If gm is reasonable doesn't that indicate a good tube?
voxmarfen said:
Yes, it's an emmission tester (http://www.tone-lizard.com/Eico.html) so you cannot measure the mA/V for the tube.
On my eico 667, EL34 are between 85 to 95; some new tubes like Svetlana C logo have 85. But thisd reflect the mA/V capacity not the emission capacity.
I found the eico inaccurate in high power tubes like 6550. Perhaps the HT power is not enough to have a precise measure
@ mashaffer / mike
yes , absolutely ! all you need is 2 digital voltmeters and a couple reliable voltagefeeds and a calculator .
i know this method is highly accurate for Gm results.
for EL34 11 mA/v is given as nominal new , (10% tolerances) , so anything between 10 and 12 is as new or very much acceptable.
i know JJ factory tests for Ia + Ig2 ( current ).
thats what they match on.
@ mgm31
thanks for the information!
i suspect readouts on the 635 and 667 are similar.
do any off your EL34 tubes fall below "50" on the eico ?
how bad would "50" be ?
eicos are budget testers , they probably need maintenance, can you adjust the needle (for calibration) ?
is there a potmeter for that ?
i would not use heavy pulling tubes in that eico either, no KT88 probably.
yes , absolutely ! all you need is 2 digital voltmeters and a couple reliable voltagefeeds and a calculator .
i know this method is highly accurate for Gm results.
for EL34 11 mA/v is given as nominal new , (10% tolerances) , so anything between 10 and 12 is as new or very much acceptable.
i know JJ factory tests for Ia + Ig2 ( current ).
thats what they match on.
@ mgm31
thanks for the information!
i suspect readouts on the 635 and 667 are similar.
do any off your EL34 tubes fall below "50" on the eico ?
how bad would "50" be ?
eicos are budget testers , they probably need maintenance, can you adjust the needle (for calibration) ?
is there a potmeter for that ?
i would not use heavy pulling tubes in that eico either, no KT88 probably.
I was sick of watching simple emission testers go for (at the time) $300+ and decided to build my own grid-shift tester.
It's pretty accurate if used right.
Cheers!
It's pretty accurate if used right.
Cheers!
I recently got an AVO mkIII for free 😀
The meter was broken though. I ordered a new one with a measuringamplifier kit at Crowthorne tubes
I put the inside of the new unit in the old case and the PCB with the instrumentamplifier at a free place inside the AVO tester.
Now I have a very well working unit. 😎
The meter was broken though. I ordered a new one with a measuringamplifier kit at Crowthorne tubes
I put the inside of the new unit in the old case and the PCB with the instrumentamplifier at a free place inside the AVO tester.
Now I have a very well working unit. 😎
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hi there,
I own a tester which i haven't seen yet.
So, i thought, i'll throw it in!
It's a Hickok I-177B....
It was used as a military tester, in the field, in WWII.
Because use in the field is very rigorous and a lot of shaking and bouncing occus, they decided to put in a mercury-vapor rectifier........laying on it's side (horizontally)
For some reason, this works very well, although ALL MV-rectifier datasheets say it is forbidden to operate the tube that way....
It is a very simple tester to operate and it's accuracy amazes me....
the rectifier is directly in the measuring circuit, so, a new 83 was bought, with both halves matching.
Via the use of the extension kit mx949 it is possible to test a lot of tubes.
unfortunately, not all tubes are listed in sheets (especially not the noval types, because the tester is from an earlier era)
The tester uses two potentiometers L&R, which set the sensitivity of the needle, knowing this (and having found a method on the internet....🙂🙂🙂🙂 it is possible to virtually measure every tube, which fits in the sockets.
it really is a military tester:
😉
http://www.uploadarchief.net/files/download/ssa43280.jpg
I own a tester which i haven't seen yet.
So, i thought, i'll throw it in!
It's a Hickok I-177B....
It was used as a military tester, in the field, in WWII.
Because use in the field is very rigorous and a lot of shaking and bouncing occus, they decided to put in a mercury-vapor rectifier........laying on it's side (horizontally)
For some reason, this works very well, although ALL MV-rectifier datasheets say it is forbidden to operate the tube that way....
It is a very simple tester to operate and it's accuracy amazes me....
the rectifier is directly in the measuring circuit, so, a new 83 was bought, with both halves matching.
Via the use of the extension kit mx949 it is possible to test a lot of tubes.
unfortunately, not all tubes are listed in sheets (especially not the noval types, because the tester is from an earlier era)
The tester uses two potentiometers L&R, which set the sensitivity of the needle, knowing this (and having found a method on the internet....🙂🙂🙂🙂 it is possible to virtually measure every tube, which fits in the sockets.
it really is a military tester:
😉
http://www.uploadarchief.net/files/download/ssa43280.jpg
voxmarfen said:
50 is in the BAD zone as I can remember.
I have a service manual (found on internet) and there is a calibration procedure but the major adjustment is the "line" adjustment made at each measure with the tube inserted. The goal of this adjustment is to adapt the primary voltage to the real needed voltage.
I found the leak on high power tube with compare on a 6550 tube between the eico and a high performance tester (metrix U61), the 6550 on eico show a "yellow" zone (about 60/70) and metrix show a good mA/V
Looking for a couple knobs for an Eico 666 tube tester, I think the 667's are the same, I need two small knobs and one larger pointed knob. Please contact me if you can help me out.
Thanks,
Tom L.
tmlesko at comcast.net
Thanks,
Tom L.
tmlesko at comcast.net
I've just aquired a B&K 747, and a
near mint Fisher X100 w 7189's.
I intend to do some comparison testing
as well as XRay the differences in 6BQ5,
EL84,7189,6P14P,6P15P. This will be the
first time I can test Mutual Conductance.
My old SICO tester only checked shorts
and emissions, this will be much better.
I am not too sure why some pentodes of
this family are rated for higher (or lower)
voltage with very little if any structural
physical differences. With exception of
RCA in the samples I've seen so far.
Perhaps the difference is vacuum quality?
Perhaps certain pentode screens are better
aligned with the G1's shadow (even without
beam forming plates as RCA's 6BQ5 had...)?
near mint Fisher X100 w 7189's.
I intend to do some comparison testing
as well as XRay the differences in 6BQ5,
EL84,7189,6P14P,6P15P. This will be the
first time I can test Mutual Conductance.
My old SICO tester only checked shorts
and emissions, this will be much better.
I am not too sure why some pentodes of
this family are rated for higher (or lower)
voltage with very little if any structural
physical differences. With exception of
RCA in the samples I've seen so far.
Perhaps the difference is vacuum quality?
Perhaps certain pentode screens are better
aligned with the G1's shadow (even without
beam forming plates as RCA's 6BQ5 had...)?
Hello everyone
I am new here and I do not speak English. I am Portuguese
I recently bought a EICO 667. I already did the repair panel meter that was broken. I have also done the calibration. The problem now is that I do not know the correct procedures to test the tubes. Who can help me?
Thank you.
jojovadi said:
Hello everyone
I am new here and I do not speak English. I am Portuguese
I recently bought a EICO 667. I already did the repair panel meter that was broken. I have also done the calibration. The problem now is that I do not know the correct procedures to test the tubes. Who can help me?
Thank you.
We have a Bingo:
http://www.radioera.com/shop/item.aspx?itemid=2784
I got mine from them for my 1947-made Precision brand tester.
Hello iiman
I appreciate your help but my big problem is the English language. What I wanted was that in Portuguese, Spanish or French
Hello iiman
Do not spend money to buy manualbooks.
go to: http://bama.sbc.edu/
Or to http://bama.edebris.com/manuals/
You find almost everything of everything ... free...
To my regret, is all in English
See you soon
João
Help with Stark 9-66 Calibration
Hello,
I have a question for you relative to my newly acquired Stark 9-66, and was wondering if you might be able to help me. The tester I purchased has some pretty good age to it (has the yellow/brown tweed covering on what is left of the case) and has been used hard. Even so, it is pretty much a sound unit. I am trying to calibrate it, and have uncovered some anomalies. Key to these reside in the bias circuit.
First off, my 3000 ohm R7 bias pot has been replaced with a linear one. I believe I can work around this since I have received the ohm readings of a tapered pot from another Stark/Hickok unit.
My bigger concern has to do with my bias voltage. At full clockwise rotation (bias setting of 100) the DC Grid Bias voltage should read munus (-) 39 V, plus or minus 1 volt. Mine reads 45 Volts; clearly out of speck. On sister Hickok units (533 and 600) the 6000 ohm R6 power resistor has a sliding tap and is adjustable to bring this in line. The R6 power resistor in the Stark unit is a fixed resistor.
I had a relatively high ohm (33K) resistor connected in parallell to the outside most posts of R7, but this did not show on the schematic so I removed it. I have (on a temporary basis) placed resistors of varying magnitude across these outside posts in an effort to bring the overall DC Grid Bias voltage back to the -39V it is supposed to be, but this doesn't seem to be working very well since it reduces the overall resistance of R7 significantly.
Do you know how I am supposed to get the -39V DC Grid Bias voltage on the Stark 9-66 aligned properly? Any help would with an answer to this or any other info on the care, feeding and calibration oft my Stark 9-66 be greatly appreciated.
Also, what is you friend intending to do with the surplus expansion panels? It would be great to install one of these onto my tester once I get my unit properly aligned.
Dave
Hello,
I have a question for you relative to my newly acquired Stark 9-66, and was wondering if you might be able to help me. The tester I purchased has some pretty good age to it (has the yellow/brown tweed covering on what is left of the case) and has been used hard. Even so, it is pretty much a sound unit. I am trying to calibrate it, and have uncovered some anomalies. Key to these reside in the bias circuit.
First off, my 3000 ohm R7 bias pot has been replaced with a linear one. I believe I can work around this since I have received the ohm readings of a tapered pot from another Stark/Hickok unit.
My bigger concern has to do with my bias voltage. At full clockwise rotation (bias setting of 100) the DC Grid Bias voltage should read munus (-) 39 V, plus or minus 1 volt. Mine reads 45 Volts; clearly out of speck. On sister Hickok units (533 and 600) the 6000 ohm R6 power resistor has a sliding tap and is adjustable to bring this in line. The R6 power resistor in the Stark unit is a fixed resistor.
I had a relatively high ohm (33K) resistor connected in parallell to the outside most posts of R7, but this did not show on the schematic so I removed it. I have (on a temporary basis) placed resistors of varying magnitude across these outside posts in an effort to bring the overall DC Grid Bias voltage back to the -39V it is supposed to be, but this doesn't seem to be working very well since it reduces the overall resistance of R7 significantly.
Do you know how I am supposed to get the -39V DC Grid Bias voltage on the Stark 9-66 aligned properly? Any help would with an answer to this or any other info on the care, feeding and calibration oft my Stark 9-66 be greatly appreciated.
Also, what is you friend intending to do with the surplus expansion panels? It would be great to install one of these onto my tester once I get my unit properly aligned.
Dave
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