Category Archives: Technical Interest

The 3D Printing Store

This really is a case of “If you can sketch it, they can print it.”

Joe Weisenbach demonstrated as much at our monthly meeting today. At The 3D Printing Store, they can turn your rough sketches into solid reality. They can produce fabrication-ready drawings from your sketches, make your engineering drawings fabrication-ready, or simply print your fabrication-ready drawings for you. You pay by the hour for design and printer time.

It’s an inexpensive way to prototype, or to replace discontinued parts. Joe invites you to drop by and see for yourself what’s possible.

The 3d Printing Store opened in Denver, Colorado in November, 2012 and recently opened one here in Colorado Springs at 4250 Buckingham Dr, Ste 100, 80907. Call his cell phone at 351-2329 or call him at the shop at 262-2451.

Repeater Pairs

REPEATER PAIRS

Ever find yourself confused, even momentarily, about the frequencies your radio uses to work a particular repeater? Come on now, admit it, I have on occasion. So let’s review how repeater frequency pairs are specified and correlate them to your radio. This material relies heavily on the section headed Frequencies on the Wikipedia page http://en.wikipedia.org/wiki/Amateur_radio_repeater.

Download Repeater Pairs as PDF

Let’s get a clear picture in our minds of what is happening. The basic relationship to fix in our minds with regard to repeater pairs is:

  • (+) offset means the Repeater Receives on a frequency Above the one it Transmits on, think +RRAT as a mnemonic
  • (-) offset means the repeater receives on a frequency below the one it transmits on
  • Operator’s radio displays the frequency its receiver is tuned to
  • Offset amount — disregard the negative sign if there is one. Engineers refer to this as the absolute value or magnitude of the quantity between those vertical bars. The offset amount is the separation between the RECEIVE and the TRANSMIT frequencies.
  • Offset direction accounts for the sign, positive as pictured in the diagram here, negative if reversed

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