I have a Meade fork mounted 16inch RCX400. I run it on AutostarSuite ver 5.5 with a computer running Windows XP home edition, service pack 2. The scope firmware is 2.2g. I am connecting to the scope with the RCX400 driver selected in the PEMPro program. When I turn on the Meade handbox display and turn PEC on, the counter in the handbox and in the PEMPro program display run at different speeds, with the PEMPro program display running slower. This is true no matter what worm period I enter. I have tried 180 teeth , 60 teeth ( which gives a worm period 3X as long as 180 teeth since Meade uses a 3 cycle period) as well as choices much higher and lower than these. The program wants to reset the tooth selection to 117 teeth. All run slower in the PEMPro program than in the handbox. Also, the Sync PE command button on the Meade handbox display works only if the two counters are relatively close to each other already. Any suggestions to help? Thanks, John Bishop

Hi John,

Is this a MaxMount or an RCX400? I recall that hte 16" Meade mounts have a different worm tooth count.

-Ray

John,

Never mind, you said "fork mount" so it can't be the MaxMount. I tried searching for the tooth count for the 16" RCX400 fork but kept getting references to trhe MaxMount. What does your manual say? Try using 360/3 = 120.

-ray

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CCDWare, Ltd. CCDWare Support Community Forums CCDWare Products PEMPro Sync failure between Meade handbox and PEMPro RA PEC counters

Thanks Ray - I will try 120 teeth. Believe it or not the manual has no mention of the number of teeth. John Bishop

John,

I think it must be a well kept secret because I could not find a reference to th etooth count either. I do know the worm wheel is twice the diameter (11") so it makes sense that the tooth count would be doubled.

-Ray

I spoke to Meade customer support today and they told me the 16" fork mounted RCX400 has a RA gear with 200 teeth , so the next chance I get at my remote site I will try 200 teeth and also 66.6666667 teeth to allow for the 3 cycle algorithm of Meade. John Bishop

John,

OK, once you confirm that then I'll update my documentation and put an option into the Mount Wizard to support it.

Thanks,

-Ray

I also have this problem .. but I have a RCX400 12". The worm does not seem to stay in phase over a 24 munite cycle. I have also seen that when the 24 minutes is up and the data repeats itself, the peaks and troughs do not overlap correctly, with there being a positive phase shift (by up to 30 seconds over 24 minutes) before seeing the same pattern repeated (see enclosed image test2.jpg)

I have also noted that the trace is shifted up or down on the second cycle, which depends on the value I choose for custom tracking rate (I use a modified ROM in the autostar giving me fine control over this). However, I seem to find right now that varying the tracking rate to be faster or slower than sidereal does not alter the fact that I get this positive phase shift.

I am using Arjay's RCX400 driver (ascom) which in PEMPRO v2 sets the worm period as 1436.07

Any ideas?

Dom Storey
Riseley, Berkhire UK

Dom,

Could you please use a watch or stopwatch (but not your PC) and time how long it takes for the Meade's hand controller goes through 600 counts?

It's normal for the cycles to drift between cycles. That can be caused by refraction, flexure, polar alignment errors, slightly inaccurate tracking rate, etc.

Thanks,

-Ray

Gday Ray

Just looking at the latest RCX firmware ( 2.2i ).
If its a std Fork mounted 16" RCX,
then the ratio and toothcount appear to be identical to the 16" LX200GPS
Ie 350 teeth

Andrew Johansen Melbourne Australia

Hi Andrew,

Thanks for the input! Did you see that someone from Meade said the tooth count is 200 for the 16"? Do you think that is inaccurate based on what you can "see" in the firmware?

-Ray

Gday Ray

200 "teeth" is totally wrong.
I suspect they may have got number of PEC bins per rev mixed up with total toothcount.
The code is very simple in PEC training
Ie, If 16" use 350 else use 180

Andrew

Thanks for the info. I tried 200 teeth as well as 200 divided by three ( 67 teeth, the program will not allow a non-integer number), as well as teeth counts from 20 to 2000, no matter what setting the PEMPro pec segment counter always ran slower than the Meade Handbox and Handbox display counters. In fact, changing the teeth count did not seem to make the PEMPro counter change its rate at all. Perhaps I am not setting it correctly. I am setting the worm period in the PEC tab, then the set up tab, then click the calculator, enter teeth number, then OK. If this is not the correct manner, let me know. By the way, I believe the mechanical aspects of the 16" RCX fork mount and the 16" LX200GPS fork mount are the same, although obviously the electronics are different. This should mean they have the same tooth count ? 350. Any additional suggestions on getting the PEC counters to sync the rate better would be appreciated. Thanks, John B.

John,

You can't enter a non-integer number of teeth in the worm period calculator. You can however enter any decimal number into the worm period setting.

With that said have you done what I asked above? That is time how many seconds it takes for 600 counts to pass? This would help confirm that 350 teeth is correct.

-Ray

John,

You should try changing the mount type in PEMPro to "Meade LX200R 16". It will work ok even though your mount is an RCX400. The tooth count is 350 for this mount type.

-Ray