Sunday, January 31, 2010

Centre-line tuned loop

After the daugther got a new bike (long time ago) and we recently had to move the old bike has to go to the recycle center.

Well i thought the front wheel would make a nice loop antenna.

In my search for possible options of came across:

1) "regular" top tuned and a coupling loop / gamma match.
2) G3LHZ's centre-line tuned loop with a twisted gamma match.

The first one takes that the rim is cut to fit the tuning capacitor. The second one looks better at first glance, since no cutting of the rim is needed.

Further more Mike's writes that the voltage over the tuning capacitor is lower due to this form of loops needs a higher capacitance.

In the document in CARC post, Mike talks about a 1,7m in diameter loop and 3300pf for using it on 160m. I wonder what I can get out of a 0.54m in diameter loop using centre-line tuned method?

Saturday, January 30, 2010

Talking about energy in food

As some might know my wife / xyl is from Texas.

Due to this fact we have many conversations over measurements.

One of the latest was about the energy in food items. In USA they are measured in Calories and here in Denmark the Nutrition labels states them in kj and kcal.

After many talks forth and back I found this web site:
Energy Converter

On there i found out that:
1 kilocalorie (IT) = 1 calorie (nutritional)

Where as:
1 kilocalorie (IT) = 1000 calorie (IT)

Notice that there are different "versions" of calories, a scientific and a nutritional.

Lesson learned .. second thought .. I got to think of f.ex. Oz. are used in both solid and fluid versions!

Friday, January 15, 2010

IPhone + GoodReader + cadaver

After trying one PDF reader I went on to try another one. This time:
GoodReader it was a wooping 6 DKK ~ 0.99 USD.
First impression was very good. There is a simple web interface for uploading files to the IPhone via wifi. It is simple, but good, it gets the job done.

Though it is trivial to upload a file at a time.

So I just installed the port cadaver a cli WebDAV client. Since I have used ftp clients in CLI (Command Line Interpretor) mode before it was quite simple to use to upload multiple files in one go.

This makes it very easy to organize the files.

Now I have most of the pdf's I use right in my left hand (8

Monday, January 11, 2010

Spring cleaning. (in the middle of the winter)

Just moved.

So as things are put into place they are being evaluated, to be placed on shelf etc or long time storage (The local recycle place).

I have alot of PCB's with just one or two components on that i might could use some other time.

So this evning some time was spent on desoldering some of these components to be able to discard the rest of the PCB.

A 150W gutter soldering irong works, though not for relays and things that size.

What I mainly has harvested has been switches, high voltage caps 3.5 mm female jacks.

Also got a couple of shelfs put together for a place for some of my instruments.

The main idea .. more room for usable "stuff" and get rid of the rest.

.. easy said .. hard to do ..

Thursday, January 7, 2010

Sprat-on-CD + IPhone + Aji Reader PDF + local webserver = Sprats on IPhone

I received my copy of "Sprat-on-CD" yesterday.

First thought was how to read them when away from my computer.

Second made a backup copy to an USB flash stick.

I do not own an ereader, though i do own an IPhone 3G .. think think ..
Into Appstore i went for a PDF reader that could download/fetch PDF documents from a web server.
I chose the Aji Reader PDF, mainly due it is free (8

Due to i'm running FreeBSD on my computers i had to setup a webservice, i chose cherrypy and compased a small index function.

Basicly any webserver that can produce an index and server the files can be used.

Go to "Fetch" enter the address on the webserver.

145 taps later I now have Sprat issues 1 to 140 on my IPhone to read when ever I like.

What I have learned about the Aji Reader PDF is as follows:
1) When restarting the app it starts where one last read in a PDF.
2) Zoom to prefered view, then tap once about in the middle of the screen, then tap on the unlocked lock, it will now show up af locked, this means that one can only scroll up/down even when the finger scrolling is now straight up or down. To undo do the same as when locking.

This app could also be used for datasheet and so on.