[Premium-Rx] HF antenna splitter

[Martin Cook]

Hi guys,

 

I followed the recent thread concerning HF antenna splitters with interest
as

after a recent house move I am running my NRD515 and an ancient Kenwood 

R2000 from a Hy-Gain 18AVT/WB amateur bands trap vertical and was getting

tired of plug swapping!

 

A little web browsing came up with a couple of interesting sites:

 

http://www.dxing.info/equipment/rolling_your_own_bryant.dx

 

and other links contained within that page, and

 

http://www.qrp.pops.net/swl-ant-split.asp.

 

In the end I decided on the original circuit in the "Rolling your own"
document,

except I used an FT50-43 toroid for no reason other than I had some!

Same windings, 12 turns equally spaced around the circumference and 8 turns
bifilar interleaved.

Three BNC sockets and an Eddystone diecast box and the job was done.

 

Performance - well I no longer have access to the test gear previously
available

since retirement but comparative analysis (ie I tried it and it works!)
shows that

compared to straight through on various frequencies from Broadcast band up
the 19metre

HF broadcast I seem to have lost about a half of an S-point when the signal
is peaking at about S7

on both receivers. I can see no significant change in either receiver when
the other changes

frequencies except when the NRD515 is switched to below 600kHz, where the
R2000 loses an S point on 

15.240MHz - Radio Australia. It seems to make very little difference to one
port if the other is loaded

with 22 or 100 ohms. All in all, I would say this is a success!

 

Pictures available on Photobucket:

 

http://i304.photobucket.com/albums/nn180/majoco21/splitter1.jpg

 

http://i304.photobucket.com/albums/nn180/majoco21/splitter2.jpg

 

The toroid is hot glued to a tap washer!

 

Best regards - Marty Cook ZL2MC