Topband: Preferred Choke Baluns

[Tod - ID]

Charles:

I make 160 meter RF Chokes [Choke Baluns] by running six turns of coax
through 5 cores of Fair Rite type 31 [2.4 in diameter cores]. Five turns and
six cores will also work.


Tod, K0TO



-----Original Message-----
From: topband-bounces at contesting.com [mailto:topband-bounces at contesting.com]
On Behalf Of Charles Moizeau
Sent: Friday, March 04, 2011 9:52 AM
To: Topband
Subject: Topband: Preferred Choke Baluns


I'd be grateful to learn the preferences of users of these devices.

My set-up is 50-Ohm, 0.405" diameter (Wireman X-4XL) coaxial cable,
underground, but within electrical pvc conduit.  This attaches through a
PL-259 to a DX Engineering radial attachment plate.  The antenna is an
inverted L with its base fed just through a variable capacitor (set for my
antenna at ~ 255 pF) .

I have given thought to chopping the PL-259, stringing a bunch of Palomar's
ferrite beads on the coax and then re-attaching the PL-259.  

However, an alternative would be to insert a manufactured or home-brewed
balun, toroidal or solenoidal, between the radial attachment plate's SO-239
connector and the variable capacitor.

Physical space is not a problem because I've discovered that the DXE radial
attachment plate will fit nicely into a 12" x  12" x  6" heavy-duty gray pvc
electrical box ($33 at Lowes).  I plan to revise the existing and quite
messy above-ground set-up so that the radials will be inserted into the box
through tight-fitting and caulked notched holes in the four top edges, just
below where its cover will fasten, with their solder lugs attached to the
plate 180 degrees opposite from the conventional configuration.  In this way
the whole business can be buttoned up tightly and buried, with just the
antenna's attachment point and the capacitor's adjustment shaft sticking up.
Perhaps this plan will be inspirational to others.

I'd prefer to see any choke balun recommendations posted to this list rather
than sent directly, so as to share the "wealth". 

Tnx es 73,

Charles, W2SH         
 		 	   		  
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