[TowerTalk] What am I missing....balun

[W4AAW@aol.com]

Some years ago I noticed an advert in QST by the purveyor of a soundcard interface that claimed it could allow FSK RTTY through your soundcard!  Of course this was AFSK and clearly, the advert took advantage of newer, less experienced hams.

I called Steve Ford, WB8IMY, the Managing Editor of QST who immediately grasped the scam.  The ads were never again seen in QST.  The League is still on watch for false advertising.  I am not sure there is similar attention in any Canadian publication but none of my VE friends like wool pulled over his eyes.  

I hope this gets reported.

Mike W4AAW

Sent from my Verizon 4G LTE Smartphone

----- Reply message -----
From: "Jim Thomson" <jim.thom at telus.net>
To: <towertalk at contesting.com>
Subject: [TowerTalk] What am I missing....balun
Date: Fri, Feb 17, 2017 2:51 AM

Date: Fri, 17 Feb 2017 01:16:01 -0500
From: "Bert Almemo" <balmemo at sympatico.ca>
To: <john at kk9a.com>, <towertalk at contesting.com>
Subject: Re: [TowerTalk] What am I missing....balun

...and this device (choke) would give you over 30 dB attenuation from 1 to
30 MHz!! I'm definetely missing something!! How can this kind of advertising
be allowed? I'm no expert but I've made a few chokes and never managed to
accomplish this kind of choking impedance with a couple of turns of coax
through a few toroids. Can someone explain please! Thanks

Bert, VE3NR

##  Its  30 db or more of  return loss.  IE:  swr is flat across the spectrum.
The marker freq is set to 26.980 mhz.  I suspect its optimized for the
11m  QRO crowd.  It might  just be  type 43 and not type 31 cores used, dunno. 
33.13 db return loss  =   1.045 : 1 swr

##  add all the turns you want, and you still wont be able to get it to work
from 1.8 to 30 mhz. 

## Interesting to note his  10 kw cw, 20 kw pep 1.8 to 30 mhz version
uses  4 turns of 393 coax through  4 x type 31 cores.  RS is 3.2 k
from  13-28 mhz.    His 3.5-60 mhz version uses  4 turns through
just 3 cores.  On both these 2 version, the cores are all type 31.

##  I saw what some of the 11m ops use for their version of a  bead  balun.
They used 20-40 type 31 or type 43   2.4 inch OD torroid cores  slid over  .875 heliax. 
To get the .875 inch heliax or  LMR-1200DB  to work on a yagi, they mount the yagi
way up the mast, with a 3 turn loop around the mast, large diam loop, like 3-4 ft 
across, and below the yagi.   The 1.4 inch ID cores are only .5 inch thick, so they gotta
use a lot of them.  Ceases to amaze me what folks come up with.

Jim  VE7RF


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