Pitch Antenna Linearity

Posted: 12/29/2005 12:12:37 PM
dulcimoo

From: COWafornia

Joined: 3/23/2005

Has anyone modified their Etherwave™ to have the pitch response more linear? If so – how?
Posted: 12/7/2006 11:39:56 PM
buddy_craigg

From: Kansas City MO USA

Joined: 11/26/2006

i bet the poster has died from old age, but after i put my etherwave back together tonight, i can not get to zero beat unless my hand is about 3 inches from the antenna.

it worked fine last week.
really the only thing i've done is varnish the upper half of the case.
Posted: 12/8/2006 12:49:42 AM
TomFarrell

From: Undisclosed location without Dick Cheney

Joined: 2/21/2005

Take the upper half of the case off and see if it works right afterward. If it does, then replace the top. If it then fails again, the problem is the varnish. If removing the case doesn't resolve it, the problem is something else. If removing the case resolves it but putting the case back on doesn't break it again, then you probably have something loose and jiggled it back into place when you opened the case.
Posted: 12/8/2006 12:56:54 AM
buddy_craigg

From: Kansas City MO USA

Joined: 11/26/2006

Hi tom,
I often write step by step trouble shooting procedures for cars, so I will cover my steps like I am a 4 year old, just so there isn’t any misunderstandings

Due to me having my inventory coming up I do not have any free time during business hours to call MOOG about this problem, so I am hoping someone here has already gone through it.

The last time I had my etherwave on it work as I would hope it would.

Since then I have
Removed the top part of the case and put one layer of varnish on it (ONLY the skyward facing part).

Removed the 90º fitting (because it was slightly off towards the right)

Cut threads in the case bottom right side with a pipe plug tap hoping it would be more straight up and down.
Reinstalled the 90º fitting but now it's leaning to the left.

I ground off the bottom 3/8” of the Pitch antenna so the ferrule becomes a ball at the end of the antenna.

I still cant get the antenna to be perpendicular to the case so I enlarge the hole of the compression nut.

The antenna looks some what straight so I quit for the night.

I have a “tiny” amount of time before I have to do real work, and since the etherwave worked correctly the last time i had the power on, I attach the microphone stand mount and 3 screws on to the bottom of the lower half of the case. The “T” nuts were already installed and planted firmly.

I put the top cover back on, put the 4 machine screws back in and now I don’t have any pitch control.

It’s a high pitch when I should be a zero beat and becomes a lower pitch as I get closer to the antenna.

When I’m about 2 inches away from the pitch antenna I get zero beat.
If I go any closer than that I’ve got about 2 inches of low to high pitch playing range.

Having the top cover off has very little effect.

So what did I do to my etherwave?

i should have just bought a black one...
Posted: 12/8/2006 8:38:42 AM
DiggyDog

From: Jax, FL

Joined: 2/14/2005

Buddy, this happens with the pre-assembled ones as well.

Maybe someone here can dig up the thread where we went over this kind of thing.

Is it possible you messed with the tuning adjustments?

Probably not on purpose but maybe accidentally when you were messing arond with the other stuff?

Posted: 12/8/2006 10:59:47 AM
vonbuck

From: new haven ct.

Joined: 7/8/2005

just like my friend who was helping restore, well did most of the work, on my 57 Rocket 88. He kept trying to fix things that didn'treally need it and just made more work for himself.
It sounds like you just need to retune the L4 or whatever it is.
It's in the manuel.

Wish I still had that car, but if I did I couldn't afford to drive it.

Andy
Posted: 12/8/2006 11:36:46 AM
buddy_craigg

From: Kansas City MO USA

Joined: 11/26/2006

mark keppinger has pointed out (in a very polite way) that i did something quite naive.

I reduced the mass of the pitch antenna, lowering the capacitance, therefore raising the frequency of the pitch oscillator.

that was just D-U-M.

i'll try adding some metal back to the 90' fitting tonight and report back.

cross your fingers ya'll.
Posted: 12/8/2006 7:23:14 PM
buddy_craigg

From: Kansas City MO USA

Joined: 11/26/2006

all is right in the world.

Marks suggestion was correct and now i just need to experement with how much metal to add back to the system.

i might be able to drop it off at Kevin's saturday after all (i'm going to be in his town for a bellydance recital)

(and no, before any of you wise guys ask, i wont be in it)
Posted: 12/9/2006 4:18:13 AM
GordonC

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

But will Kevin?

Re: the pitch antenna - that sounds like an opportunity to further personalise your etherwave. Had any thoughts as to what shape your extra metal might be?

Posted: 12/9/2006 1:46:35 PM
buddy_craigg

From: Kansas City MO USA

Joined: 11/26/2006

well... right now it's a pair of GM keys stuck in the top.

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