Ham RADIO magazines for sale 1936-1941

Discussion in 'Amplitude Modulation' started by W7TFO, Aug 13, 2016.

ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: MessiPaoloni-1
ad: L-MFJ
ad: Left-2
  1. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    I am very fortunate in that I kept my eyes wide open for certain books.
    What surprised me was they sat on eBay for weeks sometimes until I said
    "Buy it now"!
    That Jasik Antenna Engineering book only cost me 9.00 dollars!
    This is only the top of the boxes left to unload! It's funny that Dennis
    and I have the same intense need and respect for the old volumes
    of printed work that tells the truth about what we love to do.
    You won't find any of this in today's so called ham radio engineering texts.
     
  2. K5UJ

    K5UJ Ham Member QRZ Page

    If you are going to get into tube circuits and equipment, pre-coax antenna systems, then the modern handbooks leave a lot to be desired. Horowitz "The Art of Electronics" is a great source but entirely or almost entirely geared towards solid state in its current form. E.E.s tell me the schools don't even cover tubes except briefly, as in "This is a vacuum tube. Okay, let us consider the mosfet." My copy of the Radiotron red book is so old and creaky I don't open it much for fear of it falling apart. There was a nice one in good shape at a hamfest I was at this summer but the seller wanted 50 bucks so I passed. My cheapness did me in.

    My reading is unstructured--almost every night before I turn in, I randomly pick up a tube manual or handbook and flip through it and start reading. Almost always learn something but my problem is retention. I stink at that. Memory isn't what it was when I was 20 years old.
     
    N6YW likes this.
  3. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    Here's a trick.
    At any hamfest, ask your average ham what a multi-vibrator is.
    What is it used for?
    And, whats the difference between a chopper and a vibrator.
    I'm willing to bet that more than 50% of today's Ham Radio enthusiast
    don't know and frankly don't care. That's okay but a shame non the less.

    I build tube circuits almost exclusively and have for the past 20 years.
    I am known for the guitar amps that I build and restore, thus the kind
    of books I buy generally were published before 1960.
    All of the math and circuit designs of the classic stuff is still very
    relevant today.That's where creative side lives.
     
  4. K4KYV

    K4KYV Subscriber QRZ Page

    Unfortunate collateral damage to scanning vintage books and magazines and putting them on line, is that they often must be ripped apart, page by page, in order to get a good scan, and what you have left is a pile of hundreds of loose pages. With the right kind of photographic equipment this might not be necessary with certain types of binding, but many of those volumes are put together in such a way that the edge of the pages near the binding won't lie flat enough to get a good image. Some of my bound editions of pre-WWII IRE Proceedings will hardly even lie flat enough to allow one to read the content, let alone scan it. Mine came from a library that hired a 3rd party to bind bundles of loose magazines into hard covers and they did a crappy job.

    Our local library had a huge collection of periodicals dating back to the early 1900s. They said they took up too much space, so sometime in the 1960s they decided to microfilm everything. After they had finished, they didn't even offer to sell the original paper editions; they just trashed them in the dumpster! Many of the microfilm images are so blurry that you can't read them, and now, the old films are deteriorating and the viewers don't work half the time. I haven't been back there for a long time; I don't know if anyone has taken on the project of converting the microfilm archives to digital, but some of the original microfilms were of such poor quality it probably wouldn't be worth the effort.
     
  5. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Perfectly natural with the obsolescence of technology and passage of time.

    Another example:

    Ask your average Boat Anchor enthusiast what a vapor quencher is. Or the difference between a vapor quencher and air quenching. ;)
     
  6. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    Touche'
    But then again, I really don't care that much about modern technology as do for vintage.
    So Mr. Monkey Man, what is a vapor quencher and why should I care?
     
  7. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Vapor quenching as well as blown air quenching, were methods of attempting to ensure sharp delineation of the spark in spark transmitters. This would help create the purest tone or 'note" of the signal.

    -Blown air quenching: Simple method using a fan to blow air across the spark gap. The rotary spark gap was a significant improvement on this, making the gap rotate through the air instead of vice versa [although the two methods could be combined.]

    -Vapor quenching: A non-conductive vapor was used that would reduce weak sparking at the start and end of the spark event. Various liquids are used, including pure alcohol. Some radios had a simple chamber enclosing the gap and hold a bit of liquid which evaporated and saturated the chamber atmosphere.

    Later more involved methods included a series of stacking brass cups with only small chambers with a bit of alcohol splashed in them as the actual spark gap(s). This was referred to as an "Alcohol Quenched Spark Gap". These required periodic cleaning to remove the soot that resulted during the initial sparking which consumed any oxygen in the chambers.

    Pretty interesting really.

    p.s.
    Magnetic Quenching: Another method of quenching used a strong magnetic field to limit the spark. Probably a lot less common than the other two methods.
     
    Last edited: Aug 16, 2016
    WZ5Q and N6YW like this.
  8. K4KYV

    K4KYV Subscriber QRZ Page

    The simplest method was a rotary spark gap. Wasn't it self-quenching?

    Spark technology nearly identical to that of early radio transmitters is still used by Tesla coil enthusiasts. They claim that a spark rig produces higher voltage and a more spectacular display than does a tube or transistorised oscillator, although spark transmitters are said to be very inefficient power converters compared to tubes and modern devices.
     
  9. K5UJ

    K5UJ Ham Member QRZ Page

    A common argument made by AM haters who want to ban it is that a precedent was set when spark was banned. But the argument is based on a false analogy. Spark is not a mode of modulation--it is a way of generating RF as is the continuous wave from either a machine or oscillator.
     
  10. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    Fascinating! I have only ever seen one spark transmitter in use, and that is of Gary Halverson K6GLH
    who has a complete working example in his basement. Quite the contraption.
     

Share This Page

ad: UR5CDX-1