[TowerTalk] More from the M2 antennas quality control file

[Lizeth Norman]

John,
I wish it did. Believe me when I tell you that all angles were
covered. When I say "pair" I mean the like sized elements in V and H,
. Did pay attention to the details. As you say, this is tricky, with
many places for error.

Feel free to check out the pics. They show all 21 pair (same size
mistake on both!) of elements and their actual sizes versus what they
should be.

No mistakes (on my end) about it.

Norm n3ykf

On Mon, Apr 13, 2015 at 2:48 PM, John Lemay
<john at carltonhouse.eclipse.co.uk> wrote:
> The vertical elements are all shifted along the boom relative to the
> horizontal ones. Therefore a vertical and horizontal element which are
> adjacent to one another are not necessarily a "pair" and will be different
> lengths (or in some cases the same - to really confuse the issue).
>
> Does this help to explain the anomaly you are seeing ? Do study the
> dimension sheet very carefully before cutting anything - it's so awkward
> sticking all that swarf back on again !
>
> John G4ZTR
>
>
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of
> Lizeth Norman
> Sent: 13 April 2015 19:19
> To: TexasRF at aol.com
> Cc: towertalk
> Subject: Re: [TowerTalk] More from the M2 antennas quality control file
>
> Gerald,
> The element lengths do not correspond to the callouts on the
> instructions. That's 28 of 42 elements. More than a 50% screw up rate.
>
> So how does one know what element goes where in that case? Perhaps you
> can enlighten me. Crystal ball? ESP? Pig entrails? Call a psychic?
>
> This is a super big deal!!!
>
> If you think that's cool for $700, buy away!
>
> Using the tools in my garage, with the skillset my uncle taught me, I
> can do better. Coming from a manufacturer that "prides" themselves on
> "quality" and has a real factory, this is worse than abysmal.
>
> I was paying attention in engineering class when the prof discussed
> six sigma. If they've let one get out of the corral, there's more
> where that came from.
>
> Say, Don't you sell these? If I were you, I'd be very, very, careful.
> They don't have any warranty other than their "Quality". I've proven
> that to be nonsense.
>
> Math class taught me that to prove something false, I had to do it only
> once.
>
> Feel free to follow the original link to flickr page.
>
> Norm n3ykf
>
>
> On Mon, Apr 13, 2015 at 2:03 PM,  <TexasRF at aol.com> wrote:
>> Norm, this may be out in left field but I have been there before. Some
>> vhf/uhf yagis don't have the longest element as the reflector; the d.e. is
>> actually the longest element. Could this be the case with your antenna?
>>
>> Also, an error of 1/16" at 440MHz is only about 1/2 of a percent. The
> error
>> is not present on all of the elements so the effect will be very minor
>> differences of some of the lobes as seen on a computer generated pattern
>> plot. These lobes are already well suppressed so minor changes are
> basically
>> irrelevant. They may even be improved.
>>
>> You mentioned the elements are longer than expected. If you are truly
>> concerned you could trim them with a file or better yet a belt sander.If
> you
>> do that, the chamfered ends should be restored as that also has an effect
> on
>> the electrical length.
>>
>> This sounds like a non-problem.
>>
>> 73,
>> Gerald K5GW
>>
>>
>>
>>
>>
>>
>> In a message dated 4/13/2015 11:50:17 A.M. Central Daylight Time,
>> normanlizeth at gmail.com writes:
>>
>> Patrick,
>> There is no possibility of being wrong measuring these. Used an
>> adjustable (tongue) square to get a correct length measurement.
>>
>> .com/mailman/listinfo/towertalk
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