Monday, September 07, 2009

Progress on the New Four Square..........

The 75m Four Square is now finished


Just finished the new 4 square
the last part was to run the coax from the phasing box to the shack that measures dumped power
It was the most rewarding part as the good news is the system has at least 91 % efficiency
of transmit power out to the vertical
iow less than 9 % is dumped power back to the dummy load
because of inefficient coupling of the phased verticals !

I understand anything less than 10% dumped power is good.
at 3.640mhz the system is even more efficient (96%) less than 4% dumped power

It transmits apparently really well
but I think we will still be using beverages or the K9AY loop for receive and i have some work to do on those to improve our signal to noise ratios (I have been reading and studying the methods for this) Mainly decoupling the feedline from the rcv antenna system
and use of a second ground system away from the feed point


No comments: