When is an Ugly Balun just dead weight? Check out my facts and figures for Choke Baluns.
How to make high quality local contacts within a 500 mile radius.
Fan dipoles are the easiest multi-band antenna you may wish to have a go at.
You can buy an expensive switch box to accomplish phased array system. But to test out the theory if you’d like to go down this route, you could try a simple vertical yagi?
Check out my film and decide for yourself.
There are benefits to both. Height above ground will kill a vertical. But do you have the height?
Some people aren’t quite sure how easy it is to build a mono-band quarter wave. They are cheap and extremely easy to build.
Check out the video.
Surprise surprise. I was astonished that a cobweb isn’t as bad as I thought it was, certainly in software modelling.
Check it out.
A G5RV is really a doublet, using the feedline to transform (automagically) some pretty nasty impedances to a suitable impedance for coax.
I explain this here:
An inverted L is just like a vertical apart from the fact that instead of going straight up (like a tuned quarter-wave), it turns 90 degrees somewhere.
I discuss this in this video:
I cover this in my youtube video. CHeck it out.
Here’s the spreadsheet:
EXCEL: <quarter wave vertical calculator> link
In this video, I show you why you shouldn’t worry about height for your wire dipoles and loops.
Unless you can achieve leaps of a quarter-wave in size, just go with the flow (or put up a DX Commander All-Band-Vertical!
Anyone who has mucked about with verticals will no doubt have worked out that a full-sized quarter-wave for the 40m band, more or less tunes up for 15m band.
It wasn’t until my entry in IOTA Contest this year that I convinced myself that they are not a cloudburner (as many people suggest) but compare favorably with a quarter-wave, even producing more gain by 2 dB at 10 degrees above the horizon.
OK, so 2 dB isn’t a huge gain, but hey – it’s free. Take it when you can!
Don’t forget, you can do the same for 10m band too by making an element 6.83m long and folding it back a further 1.11m (for 28.5 MHz). So you’ll need nearly 8m of wire. Don’t forget, that’s insulated wire!
I’ve recently “made” a 4-element Yagi in software for my YouTube channel which should give a great match to 50 ohms.
If you’re into MMANA software modeling, here’s the file:
NOTE: This is a ZIP file because my Content Management System doesn’t like files ending in MMA. By all means have your Virus Scanner check this Zip file. There is only one file inside this ZIP. Just the MMANA file.
Here’s a really simple way of double checking how to much to trim your antenna elements.
You only need to type in the numbers in the Cyan boxes.
Just type in where it is resonant right now – then type in where you would like it to be resonant and the spreadsheet will auto-calculate the trimming.
Film: How to use the SWR Adjustment calculator.
Regulars will know about the DX Commanders very cool results which are now filtering through in real world successful contest scenarios.
My own issue is that I needed just one antenna that would deliver an all-band solution, certainly for the contest bands of 40m, 20m, 15m and 10m – but I also needed 80m in the mix too.
My holiday home has a very compact small garden so the option of putting up a dipole for 80m is out the question, but modelling suggested than exchanging the 30m element for an inverted L for 80m should work.
The 80m element therefore starts vertical, like all DX Commander elements and turns a sharp corner at 6.9m above ground and droops down for around 13m or so, hanging over a bush at around 3m off the ground. Probably not perfect but perfectly adequate to score 44 QSOs inside an hour on the Saturday eve of the IOTA contest. That score includes 16 different IOTA multipliers, certainly a wide spread around Europe.