Heathkit O-1 Oscilloscope

Discussion in '"Boat Anchor" & Classic Equipment' started by KM4HNF, Jul 9, 2018.

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  1. KM4HNF

    KM4HNF Ham Member QRZ Page

    Hello all,
    Need some info/advice on a purchase I made yesterday at an antique place in Saugatuck MI.
    As some may know, my interests lie in Heathkit equipment, and while at this store, I saw what looked like it could be a heathkit item almost buried on a bottom shelf. Turns out it is a Heathkit O-1 scope. Although an internet search revealed only 1-2 hits, I did find that this was the FIRST O-scope and the very first electronics kit that Heath every did. It sold originally for $39.95 in 1947 or 48. Little else could be found. I did a search on e-bay, and the only thing I found was an O-1 sold in 2010 for $599.00. Yes, you saw it, haha. I bought mine yesterday for $67.50!!!

    I cannot find a manual for download anywhere, but did find a schematic. The O-1 is in amazingly good condition. Faceplate is very nice. I opened it up and it is in what I would consider pretty pristine condition, and totally original, with possible exception of two orange Sprague caps that look like they went in yesterday. There are several large bathtub caps, as well as several e-caps, some of which a multi-value "can" type.

    What I'm wondering is if anyone has one, knows where to find/download a manual, and what I should do with it. I would love to get it working, and know that much depends on transformer and CRT condition. Needs cap updates, especially the bathtubs. But since it's so original, and who even knows if there is another one out there, Would I be foolish to change anything? I know there will be varying opinions, and that's a good thing. I have no problem with it possibly being worth LESS if I changed parts. I didn't buy it with the intent of making money off of it, although I was surprised at the e-bale sale price.

    I'll take some pics today and put them on here. ALL opinions and help will be GREATLY appreciated. You guys rock!!

  2. N2EY

    N2EY Premium Subscriber QRZ Page

    @W7UUU may have info.

    Eagerly awaiting the pictures!

    73 de jim, N2EY
  3. W7UUU

    W7UUU QRZ Lifetime Member #133 Volunteer Moderator Life Member Platinum Subscriber QRZ Page

    What an amazing find RJ!! Please post up photos.... the original very first Heathkit oscilloscope has no model number on it - it's just called " 5-inch Oscilloscope" in the July 1947 Radio News magazine ad. You will know if that's the one if the top of the face panel is all brown, and there is no model number. They made about 100 of them, and all sold that month! By November the face had been redesigned (not so much brown). It started to be called the O-1 about that time, with the model silk-screened. They had to give it a model number since the O-4 was slated to start shipping in December 1947. I do not believe there was ever an O-2 or O-3 - I could be wrong. I have never seen one (not to be confused with the OS-2 and OS-3 which came much later)

    The one I have is the "New for 1948" model that was first advertised in December 1948 Radio News. I found mine for $5 at a ham fest. I took it home, brought it up on a Variac, and it had a clean sharp trace! I did a cosmetic minor-restoration, new "chicken foot" knobs, and just made it look nice. It's so big and bulky I didn't have room for it in the operating position. I will leave it for some future owner to take the time to restore. I like that it's all original, does in fact work, would serve no useful purpose, so I have just let it be.

    It has the model number O-4 but is identical to the "New for 1948" ad. I suspect by the time mine shipped (early winter 1948) they had started giving products model numbers in the silk screening.

    There were no assembly manuals for any of the very early Heathkits. Just a schematic. By the time the O-4 came out, I believe they were providing a fold-out pictorial to work from. But the advanced manuals we all know and love from Heathkit didn't come along until after Howard Anthony's death in July 1954. By the late 50s and early 60s, the "manuals department" of Heath was a massive machine churning out some of the best assembly manuals ever. But the early products were "seat of your pants"

    It would be fun to recap so it's safe to turn on, and of course replace any out of spec parts (really ugly construction, at least in mine, and not much fun to work on). Then just have it play audio traces from your ham receiver or use it to display transmitter waveforms. It won't be much use at all as anything approaching a serious scope.

    I think they're so rare because folks quickly moved on to more accurate instruments and they all just got scrapped out.

    The CRT is not uncommon BTW. They made millions upon millions during WWII and can be found today as NOS. I forget the tube number but it should be visible. But the power transformer? Not likely to find a replacement. You'd have to cobble something together to supply all the voltages (which are not shown on the schematic - not on the one I have anyway) and there's no source to get them. Or use a transformer from an old scope that used the same CRT family.

    Cool find! Please do post up photos. I'll try to find the link to the one I have - I did a similar thread and there may be something there of value for you to read.

    Last edited: Jul 9, 2018
  4. W7UUU

    W7UUU QRZ Lifetime Member #133 Volunteer Moderator Life Member Platinum Subscriber QRZ Page

  5. KM4HNF

    KM4HNF Ham Member QRZ Page

    That's the post where I found YOU when I went to QRZ and did a search for the O-1 !!!
  6. KM4HNF

    KM4HNF Ham Member QRZ Page

    My Mistake Dave. Old age made me put down that mine is an O-1, and I just noticed that it is an O-3. Not as old as I thought, but pretty close.

    My cabinet is all the same color, looks like a grayish-green actually. It also has the Model O-3 on the front.
    I think I've been searching the internet for O-1 info by mistake. Maybe why I couldn't find much.

    Will try to post the pics I have in a couple minutes.

  7. KM4HNF

    KM4HNF Ham Member QRZ Page

    Trying pics, having difficulty

    Attached Files:

    W7UUU likes this.
  8. W7UUU

    W7UUU QRZ Lifetime Member #133 Volunteer Moderator Life Member Platinum Subscriber QRZ Page

    I would go so far as to say the O-3 is very likely as rare as the O-1 (or just maybe as uber rare as the "no model number" version of the O-1)!! I have never seen an O-2 or O-3 photograph. I assumed they just skipped past 2 and 3 and went straight to 4, which was a mega-seller

  9. W7UUU

    W7UUU QRZ Lifetime Member #133 Volunteer Moderator Life Member Platinum Subscriber QRZ Page

    Interesting mix of multi-era repairs it looks like! And nice to see that yours is just as much a wiring mess as mine! Without an actual assembly manual, builders just followed the schematic and stuff ended up where it ended up LOL!

    Are you planning a full-on restoration?

    Hint: don't put that transformer at any risk - replace all the electrolytics before you power up. If that transformer fails, you'll be seriously dead in the water with few easy options.

    N7ANN likes this.
  10. KM4HNF

    KM4HNF Ham Member QRZ Page

    thanks Dave.
    will do about the transformer.
    so you are saying that they didn't have a nice assembly manual like the later kits did? I didn't think of that. Guess that's why I didn't find a manual in my search. Where can i find the schematic, haven't been able to download one yet.

    As you noticed there is no green screen with grid marks and all that. Did yours come with one? Wonder if I can find one.

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