Support QRP CoA Everywhere

Wednesday, 30 March 2016

M1KTA builds a 7el Yagi for all that DX

I'll upload a photo... just put fishing touches to a nice 7el Yagi.... so I can work that DX. OK should say 5el + driven and reflector I suppose.

Inspired by W1REX in case others note the pedigree.

It is a dummy load :-) with a bit of fun added in. Measures 49.83 ohms. 5W max.

The beam is 6 1W resistors in series to make up the load, the rest of the beam is thick insulated copper wire. Hacked a length off a reel that does conduit mains feeds.

The tin, sprayed with paint was what remains after lunch yesterday, shared with the cat... finest tuna. The tower and the lid are off cuts of FR4.

An RF probe circuit exists below and if you feed in RF you can measure the voltage on two leads i have poking out of the lid to one side of the tower. I MIGHT for fun include an IM3914 and bar graph LED.

Will never be without a decent antenna at that next dummy load operating session.

Yes I had thought it might be fun to actually make this for 23cm/1296MHz so it worked for real, feed it with RG316, to measured copper tubing.... maybe next time, will be a tad larger though!

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