Sunday, December 30, 2012

A 1:1 Balun

Whilst the cobweb is being dismantled and serviced I've put up a 20 meter inverted V dipole, just so I can use the OHR100A which is set for 20M. The dipole is completed with a 1:1 Balun.  

The ugly balun is very simple to build and does the job of removing any stray rf off the outside of the coax and away from the shack. 
It only took me a morning to make and it's from various bits and pieces I had lying around, an odd length of guttering pipe, some spare coax with an SO239 attached at the bottom of the pipe. The two wires from the dipole attach directly at the top of the balun via a choc block.

It's a bit rough and ready but as long as it does the job I'm not too bothered as it will be up 30ft and no one is going to look at the cosmetics!

The cobweb has as previously mentioned been dismantled and is now lying in the shed with the connection box drying off. Once its dry I will add some more silicone and drill some draining holes in the bottom of the box. 

The replacement fibre glass poles arrived but on closer inspection were just too thin to be used to hold the twin speaker cable, so I've found another supplier and re-ordered. 

The wooden poles are actually in not too bad a condition but I would prefer fibre glass to add strength and to make the antenna lighter. The new poles must be near to an inch in width to fit the metal sleeves and will be hollow therefore lighter.

No comments:

Post a Comment