Yet another antenna experiment

So i changed QTH and now i have space to put up antennas. BTW, in the move i lost my Falcon Outback 2000 “mobile dummyload” which served me so well in my last QTH. Anyway, my first idea was to put the 11m mobile antenna up again, but since all the bands from 20 to 10m are closed now i have to put up something bigger.

In a way the end-fed antennas call to my attention. What to do? Buy one like the HiEndFed 3 band antenna? At the end it’s just a 9:1 unun and a string of antenna wire. So build one? I’ve built so many antennas in the past and nothing ever really worked.

Anyway, so i took the model for the unun of M0UKD’s website and tried to build that one using the toroid Mark PA5MW sent me a long time ago.

9to1

I strung a 14m long piece of wire to it and in my test setup i got great results! I had an SWR under 2:1 over the whole band with dips at 1.8, 3.5, 7.2 and 14.3MHz, just where i wanted them to be. But now that i fixed the coax, tightened the wire to go straight, changed the direction of the radiator about 90 degrees my SWR looks like this:Screen Shot 2016-08-15 at 08.39.31

So i don’t know what really happened? Maybe it’s the direction of the radiator, maybe the way the coax is laid out, maybe the fact that the antenna is a few meters higher from the ground but SWR has gone up and most importantly, my dips have gone. It’s not a really big issue because my ATU can match it anyway, but match or no match, a bad antenna is a bad antenna.

I haven’t grounded the antenna yet. I will try this today and see if that helps getting the SWR down. Ground is far away, so i have to figure out how to do this.

WhatsApp Image 2016-08-14 at 20.40.49WhatsApp Image 2016-08-14 at 20.40.55

 

 

 

 

UPDATE!

I just got this to help me with the project. Awaiting delivery…

Long time no update. A lot has happened.

My last post was in January this year. It’s August now. Lots of things have changed around here.

First of all i changed QTH. I now live in a place where i can mount a larger antenna IF I WANTED TO. In fact, if i wanted to get back into some serious radio i WILL have to build a new antenna because my previous antenna got lost in the move. But do i want to? This i will explain later.

Then i changed job. Where before i was working from home and never left the house, read: lots of time for radio, now i have to travel every week. So when i am at home i want to be with the family, work on the garden, the pool, the BBQ and not lock myself up in my office again to do some radio.

Then, and that’s the most important at the moment, the sun has gone really quiet lately. I know the cycle is going down, but i didn’t expect it to go down this dramatically. This was a very short and very unpredictable sun cycle. So to spend money on a tower and an antenna when there is hardly anything to listen to, no. That’s not the plan.

Let’s see. For the moment i just let my SDR create some daily heatmaps and maybe at some point, when the winter comes and conditions pick up again, i will decide to build or buy something.

UPDATE!

A second heatmap server has been installed. This time i used a leftover Raspberry Pi and a RTL-SDR adapter. This one is going to cover everything from 24MHz to 1.7GHz. At least, that’s what i understand the RTL adapter can handle.