Thank you for making this really helpful video. 👍👍👍 I acquired an Eico 667 TT some years ago and was looking at it recently. I found it in a second hand store and paid $20 and change for it. The power cord is cut and twisted together, so I need to replace or repair the cord before I can do anything. I bought an owner's manual with a bunch of other tech documents to work on it in the future after I move out of my current house. Did you know that there is an Eico 615 Tube Adapter for testing the older tubes with the Eico 667? If you get one of those adapters or build one, you shouldn't have a need for the Eico 666 TT.
Thanks for the comments. I didn't know about the 615. Cool device, I'll have to keep an eye for one. However since I already have both testers I really don't need the adapter but it would be nice to have.
@@mguess Sure, you bet. I'm looking for the 615 adapter as well. A fellow used to build aftermarket adapters, but he doesn't appear to be doing it anymore. The 615 comes up on eBay every now and then, but people have put out instructions on the internet on how to build one yourself. If you could make a video on how to build one, it would be appreciated by many people (especially me) I'm sure. Anyway, it's just a thought.
12ax7's always fall into the "replace" range on my 667; even though their actually good- a 40 or higher reading. certainly it's needing fine servicing apart from cap replacement and calibration- resistor replacement with metal films and loose socket replacements. the 667 has certainly paid for itself in sorting out the bad tubes sold by ebay sellers claiming "strong" , "no leakage", "matched". there are 2 versions (or more) of the 667- with 2 different valued resistors on the calibration circuit. thanks for the video.
I'm seeing the same thing. Known good 12ax7 as tested on one of my Hickok testers will test bad (about 30) on the 667. I'll so some investigating. The Eico roll charts as infamous for errors.
I own a hickok 752 with adaptor can test all tubes. Very accurate after I calibrated it. Since it doesn't test emissions I also own a EMC tester which can test conductance but it's not a accurate way to measure it
Thanks for the comments. The 752 looks like a very nice tube tester. I have a few Hickoks also, two 600A's and a 6000. I'm not sure about the 752 but all my Hickok testers will test for emissions only when applicable, like testing diodes and rectifiers.
@mguess yes there great for testing both emissions and mutual conductance. I went with the 752 cause much faster to test 2 sided tubes (just have to push plate 2 button) and mutual conductance is on a fixed switch instead of using shunt. So results are repeatable. I would like to own a 600a for the emissions and maybe to compare conductance results but cost of them are way more then there worth
I've got a hand me down Eico 667, has some case rust so previous water damage, but the line adjust sets well, trouble is tubes don't light up, can't test anything. Also, the 3k pot for the Plate was stuck suddenly, and I took the knob off, tried to spray the pot from the top, and got it to turn with pliers, but now feels like pot does nothing, super easy turning. Opened machine, confirmed wiper is turning in pot, so not broken, but not getting any meaningful readings from the Plate pot lugs as I turn pot with machine on. Has the pot failed, this looks like the one that is easy to source and replace, but need to troubleshoot properly. TIA
You may want to start with a good cleaning of all the controls and switches with a contact cleaner like Deoxit. Most of these old tube testers have been sitting unused for decades so the controls are sticky and oxidized. The tubes not lighting up is a concern. Did you do the test that I demonstrated in the video about testing the tube filament transformer? With power off, you can test the plate pot by measuring the resistance between the wiper and end connection. You should see a smooth change in resistance as you turn the pot. I have the manual on the 667 which includes a schematic is you need it. Good luck and let me know how the results of your restoration.
HELP!!! Hi I have been using mine for years. I have a really clean unit I got from my father. I just tested a 5U4 Rectifier tube that had a light show and blew a HT fuse in a fender guitar amp. So I tested it in my 667. It would make the transformer hum loud and it def. did not like this tube! the fuse blew in my 667 and after replacing fuse, my meter needle will not move past 5% on line adjust. I decided to take it apart and give it a look over and a really good service cleaning. I cleaned all of the pots and rotary switches and checked all of the resistors. while checking the transformer tap voltages all of the voltages were close and then the 10uf 150 cap exploded under the trim pot on the filament rotary switch side of the unit. I replaced it with a new nichicon 10uf 160 volt and the needle still won't move past 5% on line adjust. That rectifier fried something but I can't tell what it fried. I see a tiny clear diode or something I have no idea what it is or how to measure it. but you mentioned diodes and I would love it if you could walk me through identifying and checking them. Thanks for the videos. subscribed.
Wow! It sounds like that 5U4 may have been shorted internally. I just checked a known good 5U4 on my Eico 667 and it does make the transformer hum. Did you notice a short on the interelement leakage test. The "blown" electrolytic capacitor could have taken out the diode in the tube tester. Do you have the schematic diagram of the 667? If not I can send it to you. There are 2 solid state diodes in the tube tester. One is a small signal diode (the clear one). The other is a rectifier type. It should be larger and covered in black plastic. Does your multimeter have a diode test function? If so I'd recommend checking those two diodes first. Let me know the results.
Hi Can you please recommend a good replacement for the rectifier diode (CR1) in the 667........I put in an overkill 1N5408 temporarily and my needle and everything started working again, I even calibrated it. I read somewhere the old one is a selenium diode, have no idea about it's specs other than (50 Ma) in the parts list.........Thanks for your help.
Yay! Glad to hear that the Eico is working again. I was a bit worried about the meter movement itself. Those are really hard to come by. Yes the 1N5408 is probably overkill but I wouldn't change it if it's working and calibrating properly. I was going to suggest a 1N914 which is a very cheap and common small signal switching diode. The parts list isn't very descriptive but I think the original diode was probably something similar to the 1N914. It's a silicon diode not selenium. Selenium diodes are the older technology used before the development of semiconductor devices. They are much larger and feature big square metal plates in their construction. I think the part that you used will work just fine and not cause any issues. Good luck and remember be careful with suspected shorted tubes, they are tube tester killers!
Wow. Is that happening while testing all tubes. If so you may want to check the values of the resistors and pots in the unit. You may want to use a contact cleaner on all the switches.
@@Tysman909 I have 2 Hickok 600A tube testers from the early 50's. When I was looking for a transconductance tester I found that I could buy 2 "not working for parts only" testers for about half the price of a single working and calibrated tube tester. So I purchased 2 Hickok 600A testers on eBay. I was able to restore and calibrate both tube testers.
@@markwhite3443 there good testers the only issues the 666 and 667 had where errors in roll chart. I own a Hickok 752 that I restored before that tester I owned a hickok 6000a which I sold to buy the 752
I have an EICO 667 without the roll chart. My book shows data settings for loctal tubes like 7A7 & 7B6, but can't find a socket that they fit. What am I doing wrong?
@@mguess They do fit that socket next to the merit switch but they are extremely loose like the pins are two small or the holes two large. Maybe it just feels that way I never did try it. Thanks for answering
@@radiotvrepair1059 just do a eBay search for "eico tube tester". You should see a few for save. Keep checking back and look for a good deal. I bought mine for under $100 in non-working condition.
Yes, I think the one you found is a Eico 667 tube tester which is what I have. Keep checking on eBay. You may find one for a better price, $250 is a little expensive.
@@markwhite3443 just look on ebay that says for parts or not working most of time in description it says powers on and needle moves but no further testing has been done. That means it's a working tester. Only thing would do to make more accurate is replace caps and out of spec resistors and then calibrate it
