Tuesday, July 18, 2017

CHANGE OF BLOG ADDRESS

Greetings, All!


I am now posting on a new blog. The URL is:


Please adjust your links accordingly.

I will be migrating some of my posts on this blog to the new blog as I have time.

Why The Change?

A few reasons:

  • Someday, Google might say that they are abandoning Blogspot. Too much risk of losing it all due to corporate profit motives. Worrisome! 
  • Google's backup does not backup images - only text and format. Worrisome! 
  • If the Internet goes Crappo then all I've written is lost or no long accessible. Worrisome! 
  • Other reasons exist but I am too lazy to list them.
In any case, the new blog is hosted on my own server here at Hacienda de la Robinwood.


TNX
73,
Jim W7YV

Wednesday, May 17, 2017

10 GHz Microwave (3cm) Beacons on websdr.org

One of the projects on my Never Ending Project List is to build a 10 GHz Microwave Station (3 cm band). A logical first step, I think, is to build a 3 cm beacon. There is a great deal of information on that topic. In particular, KA7OEI has done lots of work and published his findings. (TNX CLINT).

Thinking about that led me to the discovery that the site websdr.org has nearly a dozen SDRs that listen to the 3 cm band. So, I thought I would make a list here and share it.

SDRs Listening To The 3 cm Band


http://websdr.suws.org.uk/  One beacon found sending FSCW (Frequency-Shifted CW) and an unidentified digital mode having four discrete frequencies.

http://maxiplaya.dyndns.org:8901/ Nice CW beacon on 10368929.65 sending chirpy code.

http://ea1rj.cloudns.cc:8888/ No beacons detected.

http://erc-websdr.esa.int/ No beacons detected.

http://websdr.fvzr.ch:8901/ Beacon at 10368086.74 sending unidentified digital mode. No CW heard.

http://microwavesdr.hopto.org:8901/ Quite pleasant chirpy beacon sending FSCW easily copied. This is the choo choo that is saying, "I think I can, I think I can." Located in Dresden, Germany.

http://sdr.dii.univpm.it:8901/ No beacons detected.

http://188.210.92.22:8901/ One beacon found sending FSCW and and unidentified digital mode having four discrete frequencies. Located in Belgium.

http://websdr.afu.eah-jena.de:8901/ No beacons detected, however, there are quite a few markers indicating the frequencies of beacons.


Wednesday, May 10, 2017

New Toy - General Radio Model 1650a Impedance Bridge

Woo Hoo! A new toy joins the shack's boat anchor collection. I used this device when I worked at Edo Western many years ago. See this page for a complete description.


Friday, April 14, 2017

Listening to Whistlers

I have an interest in building an ELF receiver that can hear whistlers. Here is a YouTube video of what they sound like:


And, here is a link explaining what they are: https://en.wikipedia.org/wiki/Whistler_(radio)

One problem is that, to hear the signals in the range of 0 Hz to 20 KHz, it is best to get well away from the urban environment with all the 60 Hz power line noise. So, I thought one could place the receiver on a mountain top. It could be powered with solar cells and beam the data back on a telemetry link (UHF) to a receiver here in the valley. From there, the data could be made available as a feed to the MESH network sites.

More later....

Thursday, March 30, 2017

RF Baluns and 20M Vertical Antenna Photos


Here are some links to photos of various projects:

Baluns



070318_Balun








Balun 070701









Balun 070709









070711 Balun









Balun 070712






Balun 070717












Balun 070718





Balun 070724














20M Vertical Antenna











  1. https://picasaweb.google.com/jim.w7yv/Vertical20M