[TowerTalk] Probelms with Modeling a LPDA

[William Turini]

During the holiday break I took the opportunity to clean and assemble my KLM
10-30 LPDA. Once I had it all assembled, the tower up and folks scheduled to
help me mount it on the tower, it snowed!  So I postponed mounting the
antenna on the tower and decided to make good use of the downtime by
modeling it in NEC-Win Plus. 

 

Hopefully I've made some horrible mistake in the input data, because I
wouldn't want to put up an antenna with the results I obtained. The SWR
looks reasonable from my past experience with the antenna, but the gain
graph looks like a dipole, i.e. no F/B ratio.  

 

I've compared my input to other LPDA designs and can't see where I went
wrong. But then again, this is my first attempt.

 

Is there anyone more experienced than I who would be willing to correspond
off-line about this?

 

Thanks

 

Bill   KA4GAV

 

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Bill Turini                                     (425) 787-4477

IT & Facilities Manager

Cypress Semiconductor - Washington Design Center