Double loaded end fed.

G0DZB

Member #84
Award Moderator
Imagine a full size dipole (for any band).
Now shorten it with a loading coil somewhere along each leg.
Now convert it to end fed by shorting out the feed point and using a matching unit to drive the high impedance at the end.

By my reckoning you should still get the high current section in the middle between the two loading coils. I wonder if this would be a practical way to build shortened verticals for the lower bands that do not require large earth systems to be efficient ?

I think I tried something similar to build a portable vertical for 17m many years ago, but on 17m the loading coils on a 7m long fishing rod were quite small ISTR. On 40m or 80m the coils are going to be much bigger to get to a electrical half wave long on a 10m rod.
 

M0TCF

Member #142
New member
Pete, have a look at the link in the thread I posted entitled 'Out and about (HF) on my tod' (its in Mobile Matters). I've just built a mono band 20m end fed dipole system that uses a toroid and a coax tuning stub. It worked great last night, even when the band was a bit flat. The designer has gone on to develop the antenna as a multi band using traps - which I don't really like - so my idea is to try another direction using switched multiple coils/toroids! I might try a loading coil for 40m as a 20m long fishing pole is a bit wayward to handle, not to mention the price!
 

M0LMK

Member #2
Full Member
Staff member
That design sounds interesting Peter. I wonder if someone can model it in EZNEC?
 

M0TCF

Member #142
New member
Peter,

No problems, as long as you remember to use my correct name as well; Lin is short for Linden (cos I'm a fella) and its an 'i' not a 'y' if you look. Thank you very much....
 
Top