[ARC5] A simple receiver improvement

[Geoff]

The ferrite in TV baluns is so small and of low permeability that it becomes 
invisible at low HF/MF. Any improvement is often imaginary or simply due to 
capacitive coupling removing the low impedance coax load off the antenna 
coils.

I wind my own and the improvement is pronounced. HF receivers with an 
antenna trimmer often need only a 100-200pf cap in series with the coax 
center conductor.

Carl



----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: <kgordon2006 at frontier.com>; "John Hutchins" <jphutch60bj at gmail.com>
Cc: "ARC-5 List" <arc5 at mailman.qth.net>
Sent: Tuesday, January 14, 2014 1:27 PM
Subject: Re: [ARC5] A simple receiver improvement


Although definitely not an "exact" match, television baluns can work wonders 
in matching the usual 50-ohm coaxial cable antennas to older receivers.

Modern baluns make it down to at least 5 MHz and usually will work on 
80-meters, 160-meters, and even lower frequencies. The "olde tyme" baluns 
often didn't make it much below 50 MHz but, because of various signaling on 
cable television, television baluns now make it down to at least 5 MHz.

Parts Express has a suitable balun for $0.79 in single quantities, $0.65 
each in the 10 to 49 quantity, and $0.58 each in quantities of 50, or more.

http://www.parts-express.com/75-to-300-ohm-matching-transformer--180-010


I have been promoting use of television baluns for well over a decade even 
in an article in Electric Radio. The text of that article can be found at:

http://k9sth.com/uploads/TV_baluns.pdf


Glen, K9STH


Website:  http://k9sth.com



On Tuesday, January 14, 2014 11:58 AM, Kenneth G. Gordon 
<kgordon2006 at frontier.com> wrote:

On 14 Jan 2014 at 6:58, John Hutchins wrote:

> Ken -
>   You talking a cheap TV-FM type 75:300   trasformer?
> Hutch

Yes. I am amazed that it really does any good at 3.5 MHz, but it does.

BTW, this is NOT my idea: I have read of some others trying this with other
old HF receivers, and having good results.

Ken W7EKB
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html


-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4259 / Virus Database: 3658/7001 - Release Date: 01/14/14