Tag Archives: stickers

Electronics

Guess the cable length to win stickers!

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Part 1:

An HP 3312A function generator is connected to an Agilent DSO1014A oscilloscope via a length of coaxial cable.  The function generator is set to generate a square wave of frequency 1MHz.

Based on the screen capture below, what is the length of the coax cable?

Unterminated Cable
Agilent DSO1014A Screen Capture

The first person to post a comment with:

  • the correct answer within ±10% of the actual measured length
  • a general explanation of how you arrived at this number (show your work!)

gets some free stickers as a reward!

Hints:

    1. The coax is labeled RG58A/U.
    2. The input impedance of the DSO1014A is nominally 1MΩ + 18pF.
    3. In case it’s not obvious, the scope photo shows two curves.  The bottom curve is a zoomed in version of the top one, showing the rising edge only.  This means that the time per division for the bottom curve is different from the top curve.  Thankfully, Agilent shows the time/div at the bottom of each so you don’t have to guess!

      Part 2 (Extra Credit):

      The function generator claims to have an output impedance of 50Ω.  Is this true?  Can you make a rough estimate of what the actual output impedance is, based on the screen capture above?

      Note: Random guessing is not allowed.  Please show that you made some honest attempt to solve the problem, even if it is by unconventional means!

      Uncategorized

      Stickers are back!

      3 Comments

      Join the Resistance!

      By popular demand, stickers are back again!

      These high quality vinyl stickers measure 8.5×1.5″ and are rated for continuous use outdoors (non geek-speak: they can be used on the outside of your car window or as bumper stickers).  The large white text on a solid black background is readable from several feet away.

      These are great for sticking on your car, bicycle, motorcycle, lab notebook, laptop, computer, old-school CRT monitor, or your friends.

      You can order them by clicking on the “Buy Now” links below, which will take you directly to Paypal’s checkout system.

      Payment is accepted via Paypal and all major credit cards.  Shipping is via USPS First Class Mail.

       

      mightyohm_resistance_smallOne sticker, $1.00




       

      mightyohm_resistance_smallDiscount three-pack, buy two, get one free!





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      Stickers are here!

      6 Comments

      Stickers are here!

      Stickers are here, just in time for the holidays!

      Each sticker measures 8.5 x 1.5″ and is made of a high quality weatherproof vinyl, suitable for indoor or outdoor use.

      Want some stickers?  For a limited time, go to the contact form and enter “sticker request” in the subject field.  Include your mailing address and within two weeks you’ll have some free stickers as a thanks for being a reader of the site.

      The free stickers are gone!  Don’t worry, if you sent a request before today (01/03/09) you’ll still get your stickers.  I hope to have stickers available again soon.

      A big shout out to Contagious Graphics, who were cheaper and have lower minimum order quantities than most other sticker vendors I looked at.  If you need stickers, check them out – tell them I sent you!