|
Post by backwardsman on Aug 10, 2007 18:59:20 GMT -7
Well, I have had my sister on the look out for old tubes at garage sales and auctions, (she lives in another state). She scored about 1200 tubes from an old guy "who used to be in the business". I just received a few from her, e.g. RCA 12AX7A; Mullard ECC83; GE 12AX7A, and I'm wondering where I might find a good source of date codes. Of the ones I have received, I would guess they are from the 60's, but I want to learn how to ID dates for th different manufacturers.
Any great web sites out there or books?
I've experimented with NOS tubes in my Z, but mainly by using the advice from this forum. I thought it time I learned a bit more....
|
|
SG123
Full Member
Posts: 221
|
Post by SG123 on Aug 12, 2007 6:22:17 GMT -7
First of all, congratulations on your score ! I'm always looking - and probably have more than a lifetime supply already - but never stumbled onto the "big stash" yet. Many U.S. tubes had easily understood date codes up until the early 60s, then went to letter codes. Since tubes theoretically "never go bad" just sitting on the shelf, jobbers would have a lot of old stock lying about. Some say the change to letter codes was brought about by customers complaining about old or obsolete stock being installed in their radios and TV, but I don't believe it. [ If you weren't the kind to install the tubes yourself, and knew something about the technology, you probably didn't go inside the device to see if the tubes were "new stock" or not. ] Anyway, you can probably tell more about the era a tube was made by looking at the box art. Here's a website that shows a lot of tube boxes arranged by brand, with the older boxes to the left progressing to the later ones. www.geocities.com/rxtxtubes/pa01000.htmThere are also some sites that have explanations of the Euro Philips / Mullard etched codes - in great detail. I have also seen one that breaks down some of the letter codes - either RCA or Sylvania, as I recall. I'll try to track that down if you're interested. The question many folks will have is "why worry about exactly when the tube was made" ? Well, the other group of folks are curious and want to know - and some place more value on the older ones... Tube World also has some photos along with a lot of date-centric info. Hope that helps !
|
|
|
Post by backwardsman on Aug 12, 2007 8:58:01 GMT -7
Thanks. That was helpful. My plan is to grab the appropriate pre-amp & power tubes from my sister for "my own stockpile", and then we will probably sell the rest--my early research tells me that most of the tubes are common radio/tv type tubes. But of course, it's a bit of a catchall--some of the boxes contain different tubes then are on the box label. I'm sure it's typical of this type of purchase. My dad once ran a radio & tv repair shop in the 50's. Up through the 70's, we had a huge supply of old tubes stored in a basement room--until of course that fateful day when we "cleaned house" and they all went to the dump!!
I am trying to educate myself as to the different tube designations and traditional uses. But of course, a little knowledge is a dangerous thing........
|
|
|
Post by mudskipper on Aug 12, 2007 15:16:16 GMT -7
|
|