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#1 |
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diyAudio Member
Join Date: Jan 2007
Location: Los Angeles
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Hey guys,
I scored an Eico 666 tube tester recently. I found info on it and replaced the 2 silicon diodes and capacitors. The unit seems to work fine, but I can't seem to get the "line adjust" to work. The meter only moves a little, and not even remotely close to the line mark. It did the same thing BEFORE I changed the diodes and caps, btw. It does test tubes fine. It's NOT the meter. I have the schematic and it's so simple an idiot can follow it. Unfortunately I'm a moron, not an idiot. I checked the resistors, and pots in the line set circuit, and everything is within spec. I have found other eico's with the same problem on ebay, but they work fine in tube test. What the heck am I overlooking ??? Anyone here have some experience with these? I searched the net, but came up empty on this issue. Thanks. Marc |
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#2 |
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diyAudio Member
Join Date: Nov 2006
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Check the line adjust pot to make sure it is not open.
Sal Brisindi |
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#3 |
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diyAudio Member
Join Date: Jan 2006
Location: SAO PAULO - SP
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Hi Marc ( runco990 ) ,
According the book “ Tube Testers and Classic Electronic Test Gear “ by Alan Douglas , Sonoran Publishing , 2000 , follow the following REPAIR TIPS : EICO 666 “ If the line adjust doesn’t work , check the selenium rectifier and the internal calibration pot , near it , and the electrolytic capacitor . The “grid” pot is prone to burnout from testing shorted tubes – pop the back cover off and look at the fibre strip supporting the resistance element , near to the zero end . “ NOTE : Alan Douglas says : “ The 666 roll charts have an unusually high number of errors , or changes from one edition to the next . The charts are numbered up to 666-09 , and while errors were usually corrected in new editions , other typos appeared each time” So , be careful !!! I hope it helps the troubleshooting , Regards , Carlos |
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#4 |
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diyAudio Member
Join Date: Jan 2007
Location: Los Angeles
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I did change the SELENIUM (not silicon, silly me) diodes and the 2 capacitors. I'll dig into the pots next.
I read about the rollchart errors... scary. The tester did come complete with manual, schematic, and rollchart supplement. It also came with a 50 cent copy of Do-it yourself TV trouble-shooters guide. (1957) COOOL!! I'll check the pots, though the meter suggests they were OK. Marc |
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#5 |
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diyAudio Member
Join Date: Jan 2006
Location: SAO PAULO - SP
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Hi Marc ,
Do it . Pay attention to the pots , may be a cracked track , may be a bad contact sliding cursor , may be one ( or more ) loose terminal (s) , may be a “cold” soldering , etc . Test it COLD , and HOT ( you can use a hair drier to raise its temperature ) . Good luck !! And don’t forget ..... read the paper Do It Yourself TV Troubleshooter , from the beginning to the end , after all , it costs half dollar , and 1957 is my birth year . Best Regards , Carlos |
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#6 |
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diyAudio Member
Join Date: Jan 2007
Location: Los Angeles
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Gentlemen, it seems I do indeed need a replacement meter for my Eico 666.
No, I do not have the skill to re-wind a meter movement..... just in case someone suggests this. I know some of you blow your own tube glass, |
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#7 |
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diyAudio Member
Join Date: Jan 2006
Location: SAO PAULO - SP
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Hi Marc ,
The EICO model 666 , has a 200 uA ( 200 microampere ) X 1000 ohms , meter movement coil . With this precious data and living in L.A. ( a big , big city ), as you are , it is not hard to find ( I would say very easy to find ) an specialist in rewinding D’Arsonval coil meter movement . You need only to get informations about it , on specialized electronics workshops , or perhaps to try the “ yellow pages” . In Sao Paulo ( where I live ) , smaller than L.A. , we have three workshops of these specialized professionals . Usually they are old people with A LOT of experience and a DOUBLE LOT of patience . In my point of view , this is the better solution , because only the meter movement , is very , very hard to find , and if you could get one , perhaps it would be in bad shape than yours . Good luck , Carlos |
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#8 |
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diyAudio Member
Join Date: Jan 2007
Location: Los Angeles
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Interesting.... I'll look into that. However, at the prices everyone charges for ANYTHING in LA, it'll probably cost less to buy another Eico on ebay. But I'll check.
Marc |
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#9 |
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diyAudio Member
Join Date: Apr 2006
Location: Fremont, California
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Hi Marc,
You are not along, my Eico-666 has had broken meter for over a year. I hope you have better luck than me finding a replacement ....
__________________
- Fred - |
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#10 |
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diyAudio Member
Join Date: Dec 2004
Location: South Florida, USA
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Find someone to rewind it - or:
You could repurpose another meter to work in the 666, although this is rather tedious. I haven’t done this myself, but I observed a friend pull this off so well that you could hardly tell the fake from the original (not a 666 though). You find another meter of the right size that fits properly into the 666 space with a 200uA movement. You can use a more sensitive movement and “pad it down”, but hopefully that won’t be necessary. There are new meters available in a broad range of sizes, although you might find a surplus meter that fits if you’re lucky. You disassemble the old, broken 666 meter. Carefully remove the back plate with the scale markings printed on it. This is usually a thin aluminum plate with two screws holding it in place. After removing any dust, you place this back plate into a scanner, and run a high-resolution color scan, saving it as a bit-map or some other uncompressed file. Now disassemble the new meter. The new meter will either be blank (unlikely) or will have its original and now irrelevant markings. You are going to cover up this old scale with a new scale. You will print out a color print image of the 666 scale on photo paper or some other sturdy stock, maybe even a plastic sheet, and you will use an adhesive to glue the new scale onto the new meter’s back plate. If the stock is very stiff, you might even remove the back plate altogether and just insert the new scale. Be careful not to bend or to torque the pointer. Turn off ceiling fans as these often are enough to make the pointers move about. You may have to use a photo editor application to adjust the size and placement of the scales for your new meter, noting where full scale and zero scale are on the new meter versus the old. Also, you’ll want to clean up blemishes and make the color and contrast right. All lines need to converge on the bearing point of course. Maybe try some black and white trials runs first. It may also be possible to just use the old back plate with the new meter, with perhaps a bit of snipping. There is never much clearance between the pointer and the back plate, so you will probably have to remove the unused plate. If you're determined, you can can exorcise the 666.
__________________
Brian |
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