Normal view
-
Q R P e r
- W2AEWβs Trapped EFHW Antenna Tutorial: Building a Smaller, More Versatile Solution for Portable Operations
Fritzel MFB-13 on the roof!
I just put up a Fritzel MFB-13, it was generously donated to me by PD9RD. The MFB-13 is a folded back rotary dipole for 10m/15m/20m. The width is only around 2 x 2.1 meters (so total length around 4.2 meters). Itβs got a βdoubleβ (10m/15m) trap in both elements, while the element length is not even a quarter wave for 10m itβs a compromise on all bands but Iβm hoping the directional effect and the height will compensate for that.
![](../themes/icons/grey.gif)
The SWR is very acceptable on all bands. Lowest SWR is a bit low on 10m and 15m but way below better than 1:1.5 on the entire band. Iβve tuned the end rods for 20m to have the lowest SWR in the middle of the band and despite of the two traps acting as loading coild on 20m the SWR is better than 1:2 on the entire band and seems to work fine on 14 MHz as well.
I havenβt put it on a rotator yet, itβs now pointing in NE / SW direction and Iβve let WSPR with 1W band hopping 20/15/10 since yesterday afternoon and, results are not bad at all:
![](../themes/icons/grey.gif)
Maybe this afternoon I will turn it in N/S direction to see if the picture looks very different.
73 Pleun