Skip to main content

The Month The Rockmite Ran Around Naked in the Woods

The gang and I were out camping for five weeks this summer. I'm finally getting a chance to take the time to write, and to look at old pictures, so you'll be hearing more about all of this, but a post on the GQRP group this morning asked about using radios without enclosures, driving me to this particular topical niche of our camping trip first. 

The GQRP poster mused about using either a plastic enclosure for a radio, or no enclosure at all. The 12 year-old here, Daize, and I had discussed mounting a radio on its battery a few times at the start of this year. As it happened, we had an extra Rockmite 20 laying around, so right before we went out for our camping trip, we moved the radio out of its case and onto its battery, this was mostly done to reduce voltage drop between the battery and the radio since the Rockmite is typically mounted at the antenna feedpoint when we're out and about. Here's the rockmite about to be launched with the antenna:


and here it is up with the antenna:


One of my biggest concerns with this setup was rain. However! Where there's a will, there's a way, and here's the rockmite with a rain enclosure assembled from a Donettes bag



The radio wasn't any noisier receive-wise in or out of a metal case. Of course rockmites are known for having wide-open frontends, so I'm not sure that's a super-valid data point.

As for tx and rx performance, at a SOTA summit, W7N/WP-147 8340 the Rockmite reached Japan on 20 m.

 

and here's the map on Google Earth








Labels:

Comments

Post a Comment

Please leave your comments on this topic:

Popular posts from this blog

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:
Post a Comment
Read more

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain
10 comments
Read more

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1.  While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero.  This is typically explained in the following way.  While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare.  That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2].  Cabrera was utilizing a loop type of magnetic monopole detector.  Its operation is in concept very sim
Post a Comment
Read more