Spark Gap BIG Spark Transmitter Telegraph Key Wireless Start Price USD 1.00 Current Price USD 200.00 Time Left - Bid Count 6 Buy It Now Price - Reserve Price - Start Time Sunday, November 16, 2008 End Time Sunday, November 23, 2008 Location Morgan Hill, CA See more about 'Spark Gap BIG Spark Transmitter Telegraph Key Wireless' Description Very Rare Adjustable High Power Multiple Spark Gap unit from Ships Wireless Transmitter Up for auction is a wonderful piece of wireless history. This huge spark gap unit was likely mounted on the front panel of a spark "Panel Transmitter" that may have been on a WW-I ship, or in a wireless office.  Many old photos show the big gap adjusting knobs like this protruding from their front panel. The multiple spark gap is basically several narrow spark gaps in series rather than one wide gap. These devices, sometimes called semi self quenching spark gaps, were used in the early 1900's just before the fully quenched unit began to appear.   There are a total of eight gaps with cooling fins that all adjust automatically when you turn the big 4 inch knob. By using multiple rather than one giant gap, you were able to handle more power and control the tone of the signal.  There is a rod (shown) which when inserted in a track on the rear, allows control over how many gaps are to be used. At one time someone slid the bar a little too hard and caused the only damage on the unit, which is a small repaired corner in the Bakelite (shown). The assembly is complete with all parts except is missing a small Bakelite cap over a bolt head (shown).  There are people who cast reproduction radio knobs who would likely be able to reproduce the little cap. The bakelite body of this unit is especially interesting.  Note the neat blood-red veining. I have been collecting spark items for many years and never run across a unit like this up for sale. It is unlikely that you will see another one.   International buyers take advantage of the very favorable currency exchange rate to pick up a priceless piece of wireless history. Use the drop-down arrow in the shipping section to select your country and postage estimate.   Place a Bid!