Just a side note, but I wouldn't
be so quick to advertise that I sell
components to those who violate
Federal Law.
73, Dick, W1KSZ
On Fri, Feb 17, 2017 at 11:12 AM, Jim Thomson <jim.thom@telus.net> wrote:
> Date: Fri, 17 Feb 2017 07:41:09 -0700
> From: Chris <EZRhino@fastmovers.biz>
> To: "towertalk@contesting.com reflector" <TOWERTALK@contesting.com>
> Subject: Re: [TowerTalk] What am I missing....balun
>
> Is there any chance this is an April Fool's joke?
>
> Chris
>
>
> On Feb 17, 2017, at 6:40 AM, ve4xt@mymts.net wrote:
>
> > I've been trying to divine a defence for this box, but can't.
> >
> > If I read K9YC's choke cookbook correctly, there's no way this could
> achieve the level of broadband choking claimed. Moreover, not only is there
> no need to enclose such a device in so expensive an enclosure, it would
> compromise power handling. And if you did, how do you mount it at the only
> place it does any good?
> >
> > When it appears the best-performing choke in Jim's cookbook is nothing
> more than a frequency-specific number of turns of coax through, at most,
> $50 in ferrite cores, with no bulky enclosure, I just can't see why anyone
> would pay $900 for this.
> >
> > Also, if the photo is akin to an "exemplar" piece of furniture, and the
> box is built to custom specifications, then the quoted specifications are
> meaningless anyway.
> >
> > BTW, isn't the attenuation noted (called return loss) the only way any
> choke actually chokes?
> >
> > I think Array Solutions has some 'splainin to do!
> >
> > Then again, PT Barnum has never been proved wrong.
> >
> > 73, kelly, ve4xt
> >
>
> #### jay at array solutions posted a note on the AMP reflector on tower
> talk. The unit is optimized for the 11m folks like I thought. Hence
> the 26.980 mhz marker on the screen. Kelly, return loss is just another
> way of expressing SWR .
> The higher the return loss, the lower the swr. You sweep the unit and
> note the return loss. IE: what is the swr with the unit terminated with a
> 50 ohm dummy load. You would expect it to be dead flat or close to it,
> on the freqs of interest.
> Same deal with LP and HP filters, or say an amplifier on bypass mode.
> At the telco I worked at, we used return loss measurements exclusively,
> and nothing was expressed in swr ratios.
>
> ### That is RG-393 coax.. Double silver plated braids and silver
> plated stranded center conductor. Teflon dielectric and FEP-9 outer
> jacket. That stuff runs aprx $7.00 per foot these days. For 20-6m,
> type 43 is typ used . If you look at the K9YC cookbook, he states either
> 31 or 43 used on 20-6m. The price tag of the unit was not what I was on
> about, but the stated 1.8 to 60 mhz freq range on their site.
>
> ## The fancy test gear is what measures the actual choke Z and RS of the
> choke. Knowing that, then you can calculate the attenuation in db of any
> shield current. I think you are confusing shield current attenuation in
> db...with return loss attenuation, which is also in db.
>
> Jim VE7RF
>
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