I've found this very interesting project by Beric Dunn, K6BEZ, about an HF Antenna Analyser for under $50

The project is based on a PIC and a dirt cheap DDS module

Check it out at :

https://sites.google.com/site/k6bezprojects/antenna-analyser

hanks to Marc, ON3LAW, I've visited a very interesting Astronomy event and had the chance to look through some nice and large telescopes.

Being a Radio Amateur of course I was curious if anybody was doing any observations based on radio waves 
( ... Or using radio-waves of lower frequency that light :-)   )

• Read more about Radio Astronomy

Recently I've been looking what projects are available to get QRV on the 4 meter band.

Although various project exist, only a few are in kit-form.

This one however is and for apx. 50 Euro (60 US) you can buy the PCB board.
Also a ready-build version is available.

You can find it at:

• Read more about Getting on 70 MHz

For those who like to experiment at higher frequencies this new product of Roberto Zech, DG0VE might interest you.

• Read more about New 10 GHz SSB/FM/ATV transvertor

I found this very interesting article on the website of G3YNH, David W Knight.

It gives an in-depth explanation on how Gas Discharge Tubes work.
One particular tube that is based on gas discharge is the Thytatron.

• Read more about Interesting article about Gas Discharge tubes