Wednesday, September 30, 2015

1/2 wave vertical experiment

The 1/2 wave vertical. Also known as fuchs antenna or more populair a endfed. I still had an old 27MHz GPA somewhere lying down in the garden en wanted to do a simple experiment. I've been experimenting with a simple endfed design before but that was more trail and error design. I wanted to do something that's reproducable. And this description from Henry (HPSD antenna's) is a very good reproducable design. Of course you can also use a piece of electrical wire instead of a old GPA.

You can find a description to built yourself here: 


It is in Dutch, but photo's speak all languages...

I was not easy to find a 2,5cm tube to create the coil. I finally found a capacitor that was big enough ;-)



Still had a old electricity box and exactly 25cm coax that is needed. Next time a take a coax that has more length. I think I need more capacity.



Difficult to see, and not clear in the description is the wire that is soldered on the second winding from the bottom of the coil the the center pin of the PL connector.

Due to the low height I think the impedance is a bit high. SWR is nice. lowest 1.2:1. From channel 1 to 40 it is lower as 1,7:1. Good enough. I used 13 Mtr ecoflex 10 low loss coax in this test.


A fast test with my only CB radio left did show good receive from stations around.


It was a nice and fast experiment and it worked out of the box. A really simple and reproducable design to make a nice antenna out of nothing actually. It could be as simple as a tranceiver, a piece of wire and coax cable, in fact that's al you need to get on the air,

73

Saturday, January 3, 2015

Goodbye good old Midland

I decided to sell one of my good old CB radios. The Midland Alan 58E. I've had a couple of 40 channel legal CB's in the past but this one was definitely the top. Sharp receive and good audio, always without a glitch.Used it mainly for packetradio in the past. I sold it to a young guy in the neighbourhood and helped him to make a antenna inside his shack from copperwire. Excellent! And very special to see that young people can still be interested in CB. I still got a spare 58E now which is in use at the job place. We had a idea to equip some trucks with CBs a couple of years ago to say hello once and a while. But till now we never installed one.