Topband: Short receiving verticals question

[Eric Tichansky]

ON4UN describes a method of "over swamping" the base of the topless 
verticals used in his four-square receive array to acheive wider 
bandwidth.  On 80M, he switches in additional series resistance to 
arrive at a total feedpoint resistance of 300 ohm, then steps down to 75 
ohm using a split winding 4:1 (2T:1T ratio) transformer (also helps 
mitigate common-mode).  This effectively increases operating bandwidth. 
See section 1.28 "The Mini Receiving Four Square at ON4UN" in Chapter 7 
/ Receiving Antennas, Fifth Edition.

I am doing some experiments with a 630M BSEF (8-circle) and have a test 
element currently using the same concept (though it is top loaded).  
1.2:1 bandwidth was originally a mere 5 kHz.  With the additional 
swamping resitance and step-down, it is now around 20 kHz.

73 Eric NO3M