13c/m LOOP YAGI MADE FROM KEY RINGS
The Picture on the left is of a loop yagi made from just key rings from the local DIY store in CLEVEDON and each ring makes two elements and you only have two sizes to get. You also require brass nuts and bolts.
I soldered the rings onto a brass bolt then that was nut and bolted to the main boom. For weather protection and birds breaking off these elements I placed the whole ant up a square section of drain pipe and sealed the ends. The driven element was a bolt drilled down the center and some small solid coax soldered to it and opened up at the top each way to feed the driven element. Note the large ring as shown in pictures on the right can be seen on the lower left picture. The back reflector can also be seen. This was a Zoomed shot taken by Ross G0WJR up on Dundry Hill out testing one very hot Feb day last year. The rings cost 14p and the large one was 28p...The rest SMA etc came from the junk box but it did get me going on 13c/m and later in the year worked over 50 miles with it with Ross G0WJR on the Mendips.....G3RFL
NEW IDEA
Now after using a glue gun a lot since we moved house and DIY I will try next a new cheaper and easier way by using a plastic trunking and gluing the rings onto that will actually be more solid and easier and I don't need to drill the boom or solder the rings onto brass bolts that are expensive. Also it will be quicker.
DIMENSIONS
RP=0mm,RL=44,DE=58,D1=73,D2=85,D3=110,D4=136,D5=153,D6=186,D7=237,D8=287,D9=338,D10=388,D11=439,D12=489,D13=540
D14=590,D15=641,D16=691,D17=742,D18=792,D19=843,D20=893,D21=944,D22=994,D23=1,045,D24=1,095 ETC.
All Dimensions are relative to the Reflector Plate (RP). The Reflector Plate is Rpw 80mm and Rph 65mm
Dia of RL=45.5mm,Dia of DE=41.4,Dia of D1 to D12=38.5,Dia of D13 to D20=37.2,Dia of D20 to D30=36mm.ETC
GAIN about 20dBi
