For sale is your choice of '50's vintage Philbrick Researches GAP/R operational amplifiers, left behind in the radio electronics inventory of my late father.  He was an active HAM radio operator for over 70 years, and was a radio and other electronics serviceman for much of his life.  He always kept a generous inventory of spare and replacement parts on hand, for speedy service calls for his customers, available for walk-in customers to his service shop, and handy for his own electronics projects.   All his components were stored in a dry, smoke-free environment. 

If you are reading this, I guarantee that you already know much more about these vintage collectible items than I do.  Much information, even specifications, is available on line.  There is a great website to check out at  http://www.philbrickarchive.org/, giving some of the history, including the very first commercial op amp, the K2-W. 

And here's the site for the whole Application Manual, referring to the different models:   http://www.philbrickarchive.org/1956_applications_manual_for_philbrick_octal_plugin_computing_applifiers_ocr.pdf   (Yes, the site does say "applifiers.")

I found these items, some with tubes, and some without, and a "collection" of loose tubes.  My dad put numbers on the tubes, for which I have no knowledge.  I will tell you the numbers taped on the tubes for the various models, if that is important to you.  I am guessing that the loose tubes may have come out of some of the items, and if you can tell by the numbers of the tube in the item, which of my spare tubes may have come out of the unit, let me know, and I'll include that one in your order.  (I hope I'm not getting too complicated.)

OCTAL BASE UNITS

K2-B  (no tubes)

K2-B  (one tube, RCA #4-43, marked T1-1020, and T2-1040)

K2-B1  (two tubes, Sylvania #039, no added markings)

K2-D  (no tubes)

K2-P #1  (tube G.E. #12AX7, marked ".05V", and Airpax Chopper #A-175)   This piece and a K2-P marked #2 were packed together, so if they operate in a pair, be aware that they were paired. 

K2-P #2  (tube RCA #-43 and Airpax Chopper #A-175)

K2-P  (brown) (no tubes)

K2-P  (brown) (one tube, Tung-Sol JTL-5751, no added markings)

K2-W  (first commercial model, 1952) (no tubes)

K2-X  (no tubes)

K2-X  (I labeled "A") (two tubes, GE #12AX7, ST 138-5, marked T1-1000 and T2-1020, and RCA 6AN8A, marked T-600 and P-7250)

K2-X  (I labeled "B") (two tubes, CBS LC, and GE #62-30, 188-5, 61-49 ...575(rest covered), marked T1-1080 and T2-1160)

8-TERMINAL AMPHENOL CONNECTOR BASES 

K2-PJ  (2 tube shields, no tubes)

K2-YJ  (2 tube shields, no tubes)

K2-YJ  (2 tube shields, two tubes, GE #12AX7 and Sylvania 12AXT7, no additional markings)

TUBES: 

These are the tubes you may pick from to complete your op amp:

GE #5751 marked:  [T1-1230, T2-1180], [T1-1120, T2-1120], [T1-1000, T2 1100], [T1-1230, T2-1230], [t1-1250, T2-1150]

RCA #4-43, or -43 marked:  [T1-1087, T2-1060],  [T1-1600, T2-1250], [T1-1200, T21170]

GE #12-AT7 marked:  [T1-5180, T2-3700],  [T1-2500, T2-3350]

GE #12-AX7 marked:  [T1-980, T2-1000],  [not marked]

GE #6211 marked:  [T1-2500, T2-2900]

 

Send me an email if you are interested, but this listing is too confusing.  I'll do my best to clarify it!!   Also email me ahead of your purchase, if you want me to include one of these tubes.   

I hope one or more of these op amps would be great in your vintage electronics or early computer collection!!   Notice that any that you purchase beyond the first one ships free of additional shipping charges!

Thanks for looking here!!

(GAP/R box, radio shelves)                            

(I have lots of other small electronics from this inventory, and if you would like other items, I will ship them in a combined shipping, and only charge shipping for the heaviest item, and all the other items you include will ship free.  Check out my other listings!!   Go ahead and buy the items, but DON'T PAY until I send you an invoice with the shipping reduced for you.)