H.H. Scott 312D

Discussion in 'Tuners' started by SEL100, May 15, 2017.

  1. SEL100

    SEL100 New Member

    Messages:
    3
    I have been a member of this forum for several years, but I have not been very active on it. So I am not aware if this topic has been discussed here before. I own two variations of the H.H. Scott 312D FM tuner. The earlier version uses conventional interstage transformers in the IF strip. This model dates from about 1968 and uses FETs in the front end and four of the typical uA703 opamps in the IF strip. It's a shame that this tuner wasn't more popular in its day (which makes them hard to find today) because it is a fabulously good performer with excellent sensitivity AND selectivity, especially since it if an early design with a single bandwidth IF. It is demonstrably better than ANY of the earlier (or later) Scott tuners - in my estimation it is the BEST tuner that Scott ever made. And it is absolutely competitive with any other analog tuners that I have used.

    Scott later made a change to this tuner and fitted it with a different IF strip that contains early crystal (or ceramic) filter blocks. This IF strip appears to use some different opamps. The first amp may be a 703 as it has six leads. But the other two amps are 8-pin packages and carry the Fairchild ID logo. But I can't read the type number on them. Part of the problem is that Scott never changed the model designation for this tuner. They should have noted the different IF with a model number something like 312D-2 or some such. The two versions look identical on the outside. So you can't tell the difference between these variations without opening them up and inspecting the IF strips. Does anybody have a schematic for this later version of the 312D? Or does anybody know what opamps were used in this later version? It's hard enough to find tech info on the earlier version (I do have the service manual for it), bui I have been unable to find ANY tech info on this later version.

    Greg Bogantz
     
  2. KentTeffeteller

    KentTeffeteller Gimpus Stereophilus!

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    Athens, TN
    I own the first version HH Scott 312D. I'd sure love a scan of that service manual on it, and I agree with you about the performance of this underrated classic FM tuner, it holds it's own with anybody's FM tuner ever built, even McIntosh's MR 78 and MR 80. My example is good for 1.6 uv sensitivity per Terry DeWick when he aligned it some years ago.
     
  3. jlovda

    jlovda Things I loved from the 60's and 70's Subscriber

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    I bought one new around 1968 (first version), selling a KLH Eighteen to get it. I sold it in 1970 to buy an MR73 ($549!). The Scott was a beautiful tuner but quite frankly I didn't think it was much better than the KLH. The designs were very similar except KLH smashed a 312D into a sardine can. I had the MR73 for almost 30 years. It was OK but I lived in Chicago most of the time and reception was not an issue.
     
  4. rmp

    rmp New Member

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    8
    Greg,

    Stout's stereomanuals.com has only the manual for the first version, but they refer to the second version as 312D-1. If you go to servicemanuals.net, the sample page (which is only the front end) is labeled D-312D-1 and dated 1968. It might be what you need.
     
  5. pdm4606

    pdm4606 Super Member

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    2,610
    Location:
    Las Cruces, NM
    I had a 312 for years when I lived in Chicago. When I moved out to St. Charles, Ill(60 miles) I traded it in for a Crown FM-1 tuner and have had it ever since.
    The 312 was noisy further out. The FM-1 was quiet all the time. Now living in New Mexico I can pick up Mexican stations easily. Even thought it needs a tune up it still works great.
     

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