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  1. S

    Obsolete Hewlett Packard Transistor

    Definitely on my to-do list. Thanks dorke.
  2. S

    Obsolete Hewlett Packard Transistor

    Thanks *steve*, made a note of it. I scrounged our salvage unit yard and came up with two of these HP 3437A's Non-functioning, but the 1853-0233's are good. I'll strip them for the parts I need to get this unit going. So I have the original OEM parts I require to do the job now. Thanks davenn...
  3. S

    Looking for new soldering station

    Here's the input of a Weller WT1012 with WSP80 user, who has recently upgraded to their WD1 with a WSP80 handle. 1) temperature accuracy is very good and there is a good variety of solder tips to choose from 2) they're darned expensive 3) when they stop working, you will play hell getting any...
  4. S

    Obsolete Hewlett Packard Transistor

    It's still on a back-burner right now, lemme take a look at it. Going by looking at the actual picture on the fold-out page, Figure 7-6 Rev A Pages 7-19 7-20. (I'm still on that rush job, so I don't have time right now to check the schematic vs the actual wiring.) And now looking at the...
  5. S

    New addition to the family :p:p

    Congrats doctor. You're a bonified life-saver.
  6. S

    Obsolete Hewlett Packard Transistor

    It's a long story, but can't post diagrams or pictures from this computer. I'll figure it out, was just trying to see if anybody heard of an equivalent for the 1853-0233. Pretty good analysis of the instrument's purpose. Think NASA and the old Voyagers. They were surprised to find one still...
  7. S

    Obsolete Hewlett Packard Transistor

    I'm on a 'more important' job right now, so I set this off to the side for a while. I have to dig deeper into the schematics to see what that 1853-0233 is for, later. The Q2 (TO-220) 1853-0233 emitter is tied to the base of Q1 (TO-3) 2N3791. The Q2 collector is tied to connector J2, pin 5, on...
  8. S

    Obsolete Hewlett Packard Transistor

    Yeah. Thanks. I know it's available as an original part. It won't make any sense to you (or me, or anybody else who actually repairs these things), but the owner has specific requirements as to component vendors. I should have mentioned that I know the original part can still be found. I just...
  9. S

    My old toy radio transceiver

    Either you and your brother handled them with kit-gloves, or they were made when quality still mattered. Nice find.
  10. S

    Obsolete Hewlett Packard Transistor

    I've got a blown HP 1853-0233 (proprietary) transistor in an HP 3437A. It's obsolete. Some guy told me he thinks a TIP42 is supposed to be the equivalent. With no 1853-0233 data sheet available, I consider that a crap shoot. Anybody know anything about a definitive 1853-0233 equivalent that's...
  11. S

    Marine Radio Transceiver repair.

    This won't be your only potential problem, but the transceivers of that era would blow the output transistor if you keyed the transmit mic with no antenna installed. So that's one thing to be aware of. Sounds like you have other problems as you have no(?) volume control for receiving. Sounds...
  12. S

    My old toy radio transceiver

    Were they made in China?
  13. S

    Finding components of a pcb(rfid reader)

    Did you try Googleing Texas Instruments TRF7960A? (I THINK you did(?)) Did you try checking the Texas Instruments website for contact information?
  14. S

    Connector identification

    As a last resort in cases like this, if I can't find a repair part, I start looking for someone selling a salvage or scrap unit (ebay or anyplace else I can find), and strip that unit for parts. The manufacturers have an annoying tendency to make a particular model for a short while, and then...
  15. S

    Connector identification

    I don't recognize it, and some manufacturers contract for custom connectors for their equipment. Have you tried contacting the equipment manufacturer to see if you can get one from them, or at least a recommendation from them for a repair/parts vendor?
  16. S

    Soldering back wires to an earbud PCB

    There are a lot of old posts in this forum explaining the best way to repair these things. I posted a few, the best explanation I remember came from KrisBlueNZ if you can find it. The temperature hasn't got anything to do with this. The problem is actual metal to metal contact.. I would...
  17. S

    I lost my solder point on board! What I do?

    While you're looking closely at your board, make sure that missing solder pad didn't wind-up against some other connection on the board, creating an unwanted short someplace.
  18. S

    Help. No idea what this is.

    The unit looked to me a lot like an old test and measurement standard. I just skimmed Google, and didn't see this exact unit, but saw articles that said Rubicon made a lot of resistance measurement standards like wheatstone bridges and such. If I had more time, I'd look some more. Try...
  19. S

    Joining NiCd batteries - conducting glue

    35 years ago there was a build-it-yourself circuit for 'zapping' dead Ni-Cads to rejuvenate them in Popular Electronics. I built one for a friend of mine and he was pretty happy with it. After all these years, thanks Audioguru for explaining what exactly that circuit was zapping. I didn't know...
  20. S

    TV HANNSPREE HG1143 main board 715G3805-M1C-000-005B schema / suggestions

    I did a quick Google search and found a lot of complaints about your model, most of which are made in China, and must be under contract to be made in other countries. I haven't seen access to a schematic, which is what you asked for in your original post. For whatever reason, it sure sounds...
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