That 239.4/42 = 5.7. That's a non-integer ratio and no way for PEC to treat that... it will have to be eliminated
mechanically if possible, or different gears used to get it to be an integer fraction of 239.4 sec, but that sounds
Sorry Michael Herman, but I'm afraid you are using the wrong worm period. The worm period is about 319.1 seconds, over which a 42.55-second frequency repeats 7.5 times. This is not correctable using PEC over a single worm cycle, but it is correctable over two worm cycles as the frequency repeats 15.0 times. The worm gear contributes about 3.7 arc-seconds peak-peak, and the 15x fundamental contributes about 2.8 arc-seconds peak-peak.
Best regards,
-Ray Gralak
Author of APCC (Astro-Physics Command Center):
Author of PEMPro:
Author of Astro-Physics V2 ASCOM Driver:
Author of PulseGuide:
Author of Sigma:
-----Original Message-----
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Sunday, November 26, 2017 10:43 AM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Help with DEC backlash/jumpy guiding
I am certain you are right... if you can identify which gear is the culprit, that should be also sent to the EQMOD
group who made up PECprep to add to their G11 list.
How does that 42 sec peak compare in size to the Worm peak at 239.4 sec. Is it anywhere near as high as
that one?
(Or better for me: send me [mherman346@...] your raw PHD2 log file and I can run it in my
PECprep.exe program to see its FFT.)
That 239.4/42 = 5.7. That's a non-integer ratio and no way for PEC to treat that... it will have to be eliminated
mechanically if possible, or different gears used to get it to be an integer fraction of 239.4 sec, but that sounds
to me like a design problem...
Best,
Michael
On Sun, Nov 26, 2017 at 10:24 AM, bvalente@... [Losmandy_users]
<Losmandy_users@...> wrote:
Michael
I would be happy to show you the 42 sec interval. i have a G11GT, and I think the tucked in motors
introduce new gearing ratios (probably true for G11G as well).
This has also been confirmed by Ray with PemPro
B
--
Michael Herman
mobile: 408 421-1239
email: mherman346@...
