Apr 082014
 

While fiddling with Tor in the last days I was wondering if I can compile the latest source code myself for a Win32 environment. The Tor FAQ gives a hint. Unfortunately the mentioned document is no longer available. It was withdrawn for a revision and a new one is not yet available. Google found a mirror and I took this as a starter. I found the document not complete and useful for the actual source code versions so I wrote an update during my build process (download below). The document is based on the source code versions available in April 2014. The whole build process was performed on a Windows 7 32bit OS running in VirtualBox. Note, the missing Tor specification documents for the package builder are not included in the source code. There is a ticket about this, obviously not yet fixed. The build process was changed for the following thinks:

a) Making of Tor uses the –disable-gcc-hardening flag to  remove the requirement for libssp-0.dll.

b) In openssl the flag -DOPENSSL_NO_RDRAND disables the default Intel RDRAND RNG because it considered insecure.

c) Uses -DOPENSSL_NO_HEARTBEATS to prevent usage of the memory leakage bug discovered on 7th April 2014.

d) Openssl and Tor building with static libraries only, so no extra DLLs are required.

Here is a screen video from the build process:

Apr 072014
 

Demolition of a 212m radio tower from 1952.
Unfortunately I missed the fall. Detonation came without warning horn after 13min of circling and according to Murphy’s law the camera was not pointing at the tower this moment. Next I got were only smoking ruins.

Apr 042014
 

Here is just another way to make a helical antenna. Cheap and easy.  Aluminum sheet reflector, cardboard tube and self-adhesive copper tape. Designed and tuned for 1240MHz this helical has 8 turns on a 85mm diameter tube.

Cardboard helical 2 Cardboard helical 1Cardboard helical 3

Update:

Added some eye-candy after flight testing. Performance is excellent. No difference to the wire wound helical I built earlier..

Tape wound helical 4

Mar 252014
 

In December 2013 Linear Technology announced a new chip – LT8490. This chip includes a 80V Buck-Boost Lead Acid & Lithium Battery Charging Controller that actively finds true Maximum Power Point in solar applications.

No yet available, that chip looks very promising. It operates with input voltages down to 6V and can boost that to charge batteries with higher voltage. I made already a schematic and board design from the preliminary datasheet that charges a 3S LiPo from a solar panel with up to 5A. A small board size allows usage in model gliders with large wing span to charge the battery in flight.

LT8490_preview2

LT8490_preview1

As soon as this chip is available from distributors the design will be online.