[ARC5] Receiver baluns

[Geoff]

FT80-43 using real isolated transformer windings, baluns are useless for 
blocking common mode. Binocular cores would be better but all I have on hand 
is the BN73-202 which is only good to about 10 MHz and I use those on the 
Beverages.

When I tried those silly little TV baluns I mostly heard neighborhood TV's 
and other noise makers. Expensive TX baluns or the overpriced receiving 
stuff from DXE is no better for that but at least they are all efficient.
I used a HQ-129X, FB7-XA, SX-28, HRO-50 and a SX-73 (civilian R-274) for 
testing. Transformers are attached to all the vintage receivers on the 
operating benches including the R-388 and R-390A.

Any of the usual transformer calculators on the internet work fine as long 
as you know some basic info. This is a good one for most anything as it also 
covers binocular cores.  TV baluns generally use them and are in the 61 mix 
category but Asian components so not directly comparable with Fair-Rite 
products.
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=19733

Carl


----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: "Geoff" <geoffrey at jeremy.mv.com>; "ARC-5 List" <arc5 at mailman.qth.net>
Sent: Tuesday, January 14, 2014 6:36 PM
Subject: Re: [ARC5] Receiver baluns


> On 14 Jan 2014 at 18:19, Geoff wrote:
>
>> I wind my own and the improvement is pronounced.
>
> What do you use for cores?
>
> Ken W7EKB
>
>
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