Terminated Flag/ Loop V Multi Turn Loop

As my antennas are indoors in my attic, I have been doing a lot of experiments with the space I have avaliable. First I tried the multi turn loop and as I have a little width and height, I made one 7 feet long and 5.9 feet high which consisted of 6 turns of 2.2 mm wire connected to a variable capacitor. I have a single turn pick up loop fed with a 31/10 turn balun. It has a figure of 8 radiation pattern and as my main interest on MW is transatlantic dx while the multi turn loop does pull in the signals I did suffer from European splatter, which made some of the transatlantic dx difficult to receive.


I looked at various designs on the web but most seemed to need a good ground like the ewe and ka9 etc. Then I saw the flag and pennant antennas which are basically terminated loops giving a good back null and "seemingly" good forward gain. So down came one of the multi turn loops but I left the pick up loop in place and changed the balun to a 48/11 turn over lapping balun and fed it with a short run of 50 ohm coax on the corner of the loop where I wanted maximum pickup. On the opposite corner I did place a 1000 ohm terminating resistor which hopefully would give me the back rejection I would need. The first test was on the 2/10/2008 at 0600 UTC with WWKB 1520 khz Buffalo, NY. I started with the multi turn loop which did receive WWKB, but with quite a bit of splatter. I then switched to the flag/loop and I must add you have to use a low noise pre amp with the indoor flag/loop. I use the Palstar AA30 and my first words were WOW! Hardly any splatter at all and WWKB in the clear. Just to be sure I switched back and forth between the flag/loop and multi turn loop and I was amazed at the lack of European and other splatter/noise on the flag/loop. The other multi turn loop was taken down and now I have one north west and one west and yes even at that small difference in deg the difference is amazing.


I have installed a switch in the north west flag/ loop at the 1000 ohm resistor which makes it in/out of use and when out of use it "seems" to have the normal figure of 8 pattern. I borrowed Ken Baird's MFJ1026 phasing unit, and with the north west loop open I phased both loops on 1035 khz where my local power house West Wound Radio is. When I normally phase antennas I usually get North Sound 2 which is to the north east but I was surprised to get a good lobe south and receive Radio Kismat in London. The terminated flag/loop is very easy to make and don't be put off by its size. It will bring in dx for you as I have been receiving USA/Canada and Caribbean most mornings as conditions allow. The other advantage the flag/loop has over the multi turn loop is that apart from peaking the pre amp which is at your receiver, once you make the flag/loop and put it in the direction that you want, you don't have to touch it. Unlike the multi turn loop, which you are constantly tuning the capacitor every time you move frequency. The following links are the videos of the difference between the multi turn loop and flag/loop and phasing the two flag/loops

http://www.youtube.com/watch?v=q2SP2Qi5J9M

http://www.youtube.com/watch?v=Kociy23DBuk

As I said the multi turn loop is a good antenna but it does have its disadvantages over the flag/loop, but it does perform well. The following link is how the multi turn loop compares to Ken's 500 meter terminated beverage, and as you will see there wasn't really much in it. (in this example !)

http://www.youtube.com/watch?v=eKoxMwKphq8

Have fun...... 73"s

David Hamilton, Scotland. (October 2008)