Topband: 2 Queations

Michael Tope W4EF at
Fri Mar 3 01:41:31 EST 2006

----- Original Message ----- 
From: "Jim & Carolyn Kingsbury" <kingsburys at>
To: <Topband at>
Sent: Thursday, March 02, 2006 11:32 AM
Subject: Topband: 2 Queations

> Has anyone measured or tried the tv cable splitters on the low frequencies
> (1.8 thru 10 Mhz)?  I wonder if they will work to combine 2 RG-6 phasing
> lines from pennant or flag antennas to a feed line to the shack.  The one 
> I
> looked at said for 5 to1000 Mhz but I'm not sure if that rules out 1.8 Mhz
> or not.

Performance is generally not too good below 5 MHz, Jim. To
squeeze 7 1/2 octaves of bandwidth out of the magic-T splitter
you have compromise the low-end performance a little to squeeze
and get good performance at 1 GHz. The CATV splitters I used
to measure were barely making spec at 5 MHz. Isolation and
VSWR at 2.5 MHz would probably not be much better than just
using a T-connector. Also, power handling of CATV splitters will
be very low. The dump resistor in the hybrid is typically no more
than a 1/8 watt rating, and the ferrite binocular core used for the
transformer is usually no bigger than 1/2 a pencil eraser.

73, Mike W4EF.........................

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