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Need help installing to a 500-C on-off switch a CL-60 current limiter

Discussion in 'Fisher' started by thornev, Feb 11, 2018.

  1. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
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    Location:
    Atwater, ohio
    Not that desperate for one, not now, not ever going the crypto currency route. Anything that exists solely in cyberspace is totally vulnerable to hacking, hijacking, or going "poof, gone"! with a few keystrokes. I prefer transactions in trade, currency &/or precious metals (gold, silver, platinum, ammunition ).
    Those who are heavily invested in said currencies ( more than just bitcoin) risk losing their asses when everyone wakes up to the scam, like lakefront property in australian outback,for example.
    Your offer's appreciated, though!
     
    Last edited: Feb 13, 2018

     

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  2. thornev

    thornev Active Member

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    479
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    Mid Hudson Valley, NY
    I "grok". I immediately changed my bank password after purchasing bitcoin.
     
  3. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Grok? I have switch location options for my switch less unit, go have a look at pics in my thread "my other 500c I thought was dead". Probably going back in that end table, & I can put a switch in that thing to control a power strip for that & the eventual turntable to sit on top. You may find that thread of interest. Cheers, thorne!:music:
     
  4. thornev

    thornev Active Member

    Messages:
    479
    Location:
    Mid Hudson Valley, NY
    "Grok" is a term from the book "Stranger in a Strange Land". 60's counter-culture book. Think of it as a synonym for "understand".

    I'm pretty sure I've read that thread as I've read just about every thread in the last few months having anything to do with FM receivers. I remember an "end table" discussion but not the details.

    Thorne
     
  5. AlTinkster92

    AlTinkster92 AK Subscriber Subscriber

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    Wouldn't touch Bitcoin with a 10 ft pole......
     
  6. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    AHHHHHHHH! The price of Technology...................

    I am Groot?!!?!?
     

     

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  7. thornev

    thornev Active Member

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    479
    Location:
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    You got me on that one, Larry. "Groot"? Would that be the Marvel tree alien from the 60's?
     
  8. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Tonight's project, out with the oem Siemens bridge, in with a junk box terminal strip loaded with a 200v 4amp kbl02. Bias voltage up (down?) from -16.4 to -20. Lots closer to nirvana of -22v. Further remediation warranted, or call it good? Rectifier running cool, but that 15 ohm r142 could cook a hummingbird egg. Must be nirmal, due to heat mark on inside of chassis. Dammit, no pic upload, file's too large-WTF? I've sent much more complex files, no problem.
    I just don't get it...:dunno:
     
  9. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,791
    Location:
    Glen Burnie Md.
    Downsize your picture files in the camera or the phone to minimum size of 800x600. My Kodak Z650 takes a 1.7m pixel pic but the smallest size is 1280x800 or thereabouts. Load it to IRFANVIEW and reconfigure the pic to 800x600 with a maximum pixels per inch of 200. 96ppi would be better and almost guarantees entry to the board. The forum won't take BMP files. It will take jpg (or jpeg), png and gif's.

    -24v would be better, but -20 is nothing to sneeze at. If you have an IBAM or IBBA board, check to see if you can bias your tubes to 32 to 34ma. If so, no real problem. Yes that 15ohm R142 can boil MRE's if you give it 1/2 a chance. Drop a 10w 15ohm ohmite in there. It'll still dissipate the same amount of heat, but it will operate in the middle to low end of SOA vs. close to the high end of the envelope. Mouser # 588-40F15RE
    https://www.mouser.com/ProductDetai...EpiMZZMukHu%2bjC5l7Yb6dPji%2bpsmCMrljh1yuV6g=
     
    Last edited: Feb 14, 2018
  10. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Roger that, Larry. Will do. Tried once before, obviously a swing & a miss.
    No bias adjust capabilities on any of my tooby fishers yet. Going one mod at a time, starting with the first 500c I acquired, s/n 71772x,God knows how long ago ( when they came cheap). So far, with you guys' help, I've done grid resistors & caps, screen stability mod, rectumfrier r&r, all from parts on hand. Now time for parts buying, such a p.i.t.a., since no more brick/mortar shops. God, i miss the old days of catalogs! I could put an order together in no time by flipping pages & picking shiite out. Such a time-consuming way now, this on-line ordeal. Next is the 10 ohm cathode poppers, mpx electrolytic, inrush limiters, 20uF help for c91a on both of these, due to hummy phono/tape head stages. Rest of cans staying put for now, both 500c's sounding good otherwise.
    Was reading archives re:the noose, worthy of concern on these units?
     
  11. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    Noose. Not as much as on the 400, but still a worthwhile consideration. Just make a note to self........US or EURO Tubes for P.I. If you can find a bunch of Yellow inked Sylvania 12ax7's they do right good. I've got an 800c with all sylvie's in it and The Executive's 800c has all Tele's in it. Can't hear any difference from them. .
     

     

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  12. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
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    Location:
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    Getting ready for phase invert adjust. Once again, you guys are a godsend! I've been accumulating gear & tubes my whole life, compared to recently I was clueless, compared to now, with my discovery of this site. Wish I'd done so a lot sooner than I did!
    Both 500c's have the oem German 'the fisher' ecc83/13ax7's in their original positions, so am good to go. Are those telefunkers or something else? But, should a need arise, I've got a couple to pick from. This pile is all au,ax,at7's, couple 6201's, maybe a couple 5814's mixed in. Sorting via hickok 533a...
     

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  13. thornev

    thornev Active Member

    Messages:
    479
    Location:
    Mid Hudson Valley, NY
    I did the phase inverter adjustments yesterday, Catman. Relatively easy. The static reading on both tube pins was 51K. One side had to be upped from around 46K. The other side already was at 51K.
     
  14. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Just finished , both 500c's were dead nuts on the mark. Had to play with pots to watch what happened, then put back on the mark. I think I'll do the x-101-d amp next. The 400 can wait. Ya having fun yet?:D
     
  15. thornev

    thornev Active Member

    Messages:
    479
    Location:
    Mid Hudson Valley, NY
    It just occurred to me. Since I've removed the wire that connects all 4 power tubes which enabled them to all get the same voltage, now that the tubes are not connected, I assume they each get their own voltage. Does this mean it's more important now for me to "tune" the tubes so that they each put out the same amperage? And if so, which pins do I want to measure to ensure the currents are close to each other? Pins 5 and 6 at least, right?

    Thorne
     
  16. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
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    Yes & no. You cut out the bus / jumper between the output tubes, disconnect bias feed from pin 8 of v-8. Thats the orange wire from c91 section 'D', the pin marked with a half-moon. You then connect them to the bias source from c91a through a 100 ohm resistor via a jumper. Couple of ways to do it. I did my first one Dave's way. Use pin 1 on v-8, bring bias juice to here, then jumper to the other 3 tubes pin 1. It's not connected internally , so it's basically a dummy pin. How convenient for this mod! Then, your 100 ohm resistor goes from pin 1 to either pins 4,8 or the bus wire between the two. Essentially, the tubes get bias voltage through the resistor.
    Bias can't be adjusted individually until the IBM or IBBA mods are done.I posted pics & my hand-drawn diagrams along with the 'after' shot of mine in previous posts. If you can't find, I can pm them to you.
    You have to remove ground jumpers from cathode to ground & install the 10 ohm resistors in their place before you can measure individual current draws across them.
     
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  17. thornev

    thornev Active Member

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    479
    Location:
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    Thanks, Catman. You may have saved my day. I already have the the pin 5 to ground resistors, and I have several drawings of the IBBA and IBBM bias adjuster mods. Now to see if I can follow the rest of your response.

    Are you saying I disconnect the orange bias-providing wire from pin 8 of V8 and move it to pin 1 of V8 and then connect that pin 1 to all the other pin 1's?
     
    Last edited: Feb 14, 2018
  18. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Yep.
     
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  19. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    Here's my finished product & diagrams. I used orange wire I had in a junk wire stash for uniformity & traceability.
     

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  20. Catmanboo

    Catmanboo AK Subscriber Subscriber

    Messages:
    483
    Location:
    Atwater, ohio
    I had to scrape the hell out of those pins, they wouldn't tin. 51 years exposure in that environment produced a film that I could see as discoloration, & it was a p.i.t.a. had to do both sides of pins carefully, to avoid bustin'one off, as they're plated brass. I used a very small pocket knife.
    Where'd you order your parts from? I'm at that stage now, all my previous mods were supplied with my personal stash of bits & pieces.
     

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