oscilloscopes, hmmm( in a good way)

Discussion in 'Amp Tech Center' started by 24 track, Sep 8, 2020.

  1. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    yesterday , I was given a Hitachi V302B dual trace 30mhz scope I am quite stoked

    it has been a long while since i had one , so I'm looking to refresher my memory cells on the use of these
    LOL

    HITACHI-V302B-OSCILLOSCOPE-with-MANUAL.jpg

    I was given a B&K 2120 20mhz dual trace as well , but there may be some issues with the sweep generator board bad caps etal.

    bkprec_2120_1.jpg

    do any of you techy types know of some good reading and or videos on the use of these , like I say its self explanitory ,but its also been about 35 years since I used one , (looking to get back on the bike , so to speak)
     
    tubegeek and Switchy like this.
  2. fidopunk

    fidopunk Tele-Holic Gold Supporter

    Posts:
    558
    Joined:
    Nov 23, 2008
    Location:
    Charleston, WV
    I own two scopes-- one solid state and one old tube driven one from the Navy. I wish I could get either to work.
     
    24 track likes this.
  3. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    I also have an old tube type from one of the TV stations here in town, it has a load of 12AX7's in it, I may part it out for components , totally out of my league to try to fix!
     
  4. tubegeek

    tubegeek Friend of Leo's

    Age:
    60
    Posts:
    3,681
    Joined:
    Jan 31, 2020
    Location:
    Brooklyn, NY

    https://www.tek.com/document/primer/setting-and-using-oscilloscope
     
    24 track likes this.
  5. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    tubegeek likes this.
  6. tubegeek

    tubegeek Friend of Leo's

    Age:
    60
    Posts:
    3,681
    Joined:
    Jan 31, 2020
    Location:
    Brooklyn, NY
    You're welcome.

    My karma needs all the help it can get.
     
    24 track likes this.
  7. Commodore 64

    Commodore 64 Friend of Leo's

    Age:
    44
    Posts:
    4,173
    Joined:
    Mar 1, 2010
    Location:
    Kent, OH
    I just twist knobs until it works. First time took a couple of hours, lol. Now, I just hope none of the knobs gets twisted too far out of whack.

    Seriously. But I'll take a look at it when I get home and let you know what kinda triggering/etc it uses.
     
    24 track likes this.
  8. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    I ran both traces last night to ensure every thing matched at the same settings I have an industrial realtime analyser and a test tone oscillator and will check things out for accuracy
    I love new toys
     
  9. kbold

    kbold Tele-Afflicted Silver Supporter

    Posts:
    1,547
    Joined:
    Jul 21, 2015
    Location:
    Australia
    Great CRO of that era. What's it not doing?
     
    24 track likes this.
  10. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    it only holds the traces as a dot and will not widen the trace more than a 1/2 inch tops , so probably an issue with the sweep gen board, maybe some old caps need replacing , there is another one for sale on Ebay but it looks like it has the same issue or I would have built one working one from the 2 units
    I love B&K stuff killer top of the line tech
     
  11. kbold

    kbold Tele-Afflicted Silver Supporter

    Posts:
    1,547
    Joined:
    Jul 21, 2015
    Location:
    Australia
    I had an old Tektronix CRO (a heavy beast with plug in modules).
    It developed a sweep fault (horiz or vert? can't remember) on one channel.
    Anyway ... the ease with repairing it was that the opposing channels run in parallel along the board: with transistor sockets!
    I only had to swap transistors along the chain to find the faulty transistor. Didn't even need a soldering iron.

    Not sure if many CRO's have transistor sockets (sockets could be used because the transistors were current driving).
    Worth a peek inside.
     
    24 track likes this.
  12. GuitarsBuicks

    GuitarsBuicks Tele-Meister

    Age:
    24
    Posts:
    215
    Joined:
    Jul 16, 2020
    Location:
    Somewhere between here and there

    Cool! I would love to get my hands on something like that.
     
    24 track likes this.
  13. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    I plan to get in there really soon , I have completed 3 amp repairs in the past 2 days and have 4 more on the block and an electric piano comming in next , after that I'm taking a break for a while , whew ! ( I know how to spend my weekends)

    today i repaired a rare Balder rack mount amp ( what a cool beast ) and still had time to check out the B&K
     
  14. tubegeek

    tubegeek Friend of Leo's

    Age:
    60
    Posts:
    3,681
    Joined:
    Jan 31, 2020
    Location:
    Brooklyn, NY
    Which sort of electric piano?

    I'm getting a Balder!

    No, that's not right....
    I'm getting balder!
     
    24 track likes this.
  15. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    I have been helping a friend with some amp repairs and he has given me a ton of parts and pieces. including the hitachi V302B , a 1977 acousic 407 bass/guitar amp with matching 8X10" cab and a Marshall 1922 2 X12 Cab loaded with celestions to match my Marshall JCM 800 combo. so its almost been like Christmas around here, lately
     
    Last edited: Sep 8, 2020
  16. BobbyZ

    BobbyZ Doctor of Teleocity

    Posts:
    12,887
    Joined:
    Jan 12, 2011
    Location:
    Snellman MN
    Gotta dig my scope out this winter and start using it. After over 20 years fixing amps, it's probably time to figure the darn things out.
    Uncle Doug has some videos on them, drink plenty of coffee. :)
     
    Telecastoff1 and 24 track like this.
  17. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    I think its a Yamaha 61 key I think it was dropped or something , but I'll soon find out , a sentimental instrument that belonged to a ladies deceased husband so I'll give it a go.
     
  18. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    great suggestion I'll check out his site for this!
     
    BobbyZ likes this.
  19. kbold

    kbold Tele-Afflicted Silver Supporter

    Posts:
    1,547
    Joined:
    Jul 21, 2015
    Location:
    Australia
    I've just waited over a month for delivery of 2 cap's to repair my own amp.
    Delivery times are not what they used to be (last year).
     
    24 track likes this.
  20. 24 track

    24 track Doctor of Teleocity Silver Supporter

    Posts:
    16,266
    Joined:
    Nov 6, 2014
    Location:
    kamloops bc
    sourcing parts and getting them is the worst part of these repairs, I had one that i ordered in feb last year arrived in june , and some times I have to but a quantity of parts just to get the one I need,
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.