Trap antenna again.
I start to create a new trap antenna for HA7AJ Attila. The requirement is to work on CW segment 3.5MHz, 7MHz, 10MHz, 14MHz, 18MHz. Maximum power is 400W.
I decided to work with coax traps with RG58 on 5cm PVC pipe to handle the power.
The plan is the following:
and here is the implementation before poliester resin coat:
After some fine tuning it is seems good on my analyser:
Then next is the 14MHz plan
The last trap working on 18MHz
After final tuning it is resonnant on designed frequency:
After a problem with resin coat I must redesign and rebuild the coax traps. The new design based on RG179U cable because it was on my desk. But the process is pretty same. At the moment there is no resin coat applied only hot melt glue fixing the coax winding.
Then an ugly balun created into the feed point.
SO it is installed on my tower and tuning process continue with antenna wire cut.
It looks pretty on my tower 😉
So after final tuning it is resonant on all required ham-band.
Usual test on WSPR only one night: