Just Sharing This My Channel Master 1.8 project.

i'll be fitting Rimants arms this weekend, and fitting the CBAND LNB for my first dip in the CBAND experience.
 
how many more inches do i have left to go further west ...this is a 24" jack - gone from 54e to its position as photographed at 45w...its used 19 inches
do you think i can reach 58w ? or will the end of the arm fall out and cause a big kerfuffle.

also to remove this plate or not? and go with either yellow or blue position?
 

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Manikm909 said:
how many more inches do i have left to go further west ...this is a 24" jack - gone from 54e to its position as photographed at 45w...its used 19 inches
do you think i can reach 58w ? or will the end of the arm fall out and cause a big kerfuffle.
Click to expand...


You should be OK for another four inches.
You might need to adjust the black flywheel cam that limits West extension if it stops before you get a full extension.

Whether or not another four inches will get you from 45W to 58W depends on the geometry of the polar mount planar triangle.

Just fit the 36" one, end of story...
There is plenty out West in C-Band for Poop slurpers.
 
@Manikm909 I wonder what you have where yellow arrow is pointed? Perhaps there should be a spacer like that pointed by the red arrow.
 

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Manikm909 said:
also to remove this plate or not? and go with either yellow or blue position?
Click to expand...

That could be dependent on which is the most easterly satellite (max. retracted) that you want to receive, and which is the most westerly satellite (max. extended)?

And blue or yellow position: maybe dependent on the triangle side lengths that you want?

Greetz,
A33
 
Manikm909 said:
how many more inches do i have left to go further west ...this is a 24" jack - gone from 54e to its position as photographed at 45w...its used 19 inches
do you think i can reach 58w ? or will the end of the arm fall out and cause a big kerfuffle.

also to remove this plate or not? and go with either yellow or blue position?
Click to expand...

Just Sharing This - My Channel Master 1.8 project.

before my new actuator arrives (which i am new to by the way, never used jacks before) i would like your advice on best position to place it. i seem to have an EXTRA plate, shown here in pic2 - i dont think this is part of original CM polar mount. first question: what do you think its for...
www.satellites.co.uk www.satellites.co.uk
 
i found a very robust CBAND LNB holder up the garage tonight.
:)
 

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omg your right!!! i fitted the prime focus style one, oh well, job for the morning - thought something didnt look right!

no, i cant get to 55w - ERR2 - i will fit the 36" in the morning - @Channel Hopper will be very pleased.
 
scopus said:
What sort of cable are you using for the pulse circuit? I use a seperate cable that is screened for the pulse circuit, I dont have any problem. Its possible that your pulses are being corrupted by interference from the motor cable. As Moonbase says really an RC2000 is the way to go..
Click to expand...
That's the reason why, elsewhere in this or another thread, I commented that "old style" multicore cable for H-H mounts or actuators was generally screened - but, to be more precise, the 2 cores for the sensing circuit were screened together, whereas the +/- 36V motor/actuator cores were not, and the sensor circuit screening was usually grounded to the Rx chassis at one end and to the motor/actuator casing at the other to create an "end-to-end" screened circuit.

BTW: I still have a few metres of that type of cable in the garage from when I took the Jaeger H-H mount down a few years ago.
 
In the RC2000's user manual, Research Concept suggests to connect the ground wire only to the controller pin but not to the motor ground. It must be leaved opened at the motor side. So, only one cap of the cable must be connected. Doing this, the cable is shielded but possible ground loops are avoided.
 
7mdish said:
In the RC2000's user manual, Research Concept suggests to connect the ground wire only to the controller pin but not to the motor ground. It must be leaved opened at the motor side. So, only one cap of the cable must be connected. Doing this, the cable is shielded but possible ground loops are avoided.
Click to expand...
OH DEAR, OH DEAR, "the old, old wives' tale" of leaving one end of the shield of a shielded cable unconnected to avoid ground loops!!!!:rolleyes:

Having worked for quite a long time in the industrial and defence sectors in EMC control (as well as electrical/electronic safety control!), I can tell you that doing this this is VERY much depricated because it leaves the sensing circuits in the motor/actuator "floating" and likely to pick up/radiate any interference that's around - including that on the motor cable cores!

As an example of something very similar, in my last job, I was given a long sensor probe to get EMC certified (for CE Marking purposes) but the first time I tested it in a screened the bloody thing spewed RF right across the spectrum and I had to abort the testing very quickly.

Investication uncovered that the cable was in 3 sections:
- 2 lengths of heavily screened cable, one of which connected to the probe
- a short intermediate section consisting of a plastic box and small circuit board, the ground connections to which were virtually non-existent, and absolutely no use for EM control because that also meant the probe cable screen and probe were effectively ungrounded for for EMC purposes.

Long story cut short: replaced the plastic box by a metal one with proper 360 deg metal cable glands at either end to ensure the circuit board was screened and that the screen was contiguous throughout the length of the probe cable, and also improved the continuity of the cable connections to the exterior control box and the probe.

Result: the modified probe sailed through the relevant industrial level RF emissions, immunity and surge tests pretty much first time. (and that did my status as a pretty new contractor absolutely no harm at all - I finally stayed there for nearly 3 yrs and fixed quite a few other EMC issues along the way :)!).

Thus, grounding the shield at BOTH the RX and motor/actuator ends ensures that any such interference doesn't get onto the sensing cores due to the "skin effect" phenomena which restricts it to the outer skin of the shield, and then to the chassis of the Rx and thus to the outer skin of a Faraday cage - thus the interference doesn't get into the internally located sensing circuits at either end.
 
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Really thank you jeallen01 for your extensive explanation. Very clear.
So, as I must really install my new setup soon (hoping soon, I'm waiting for delivery of my new 2.4m dish), it seems that I must connect both side of the shield in motor cable.
My setup provides RC2000 controller with two actuators (for elevation correction, too), so a double motor cable must be used.
Please note that non-connection to the motor side is specified more than one time and in uppercase letters in the RC2000 user manual......
But your explanation seems totally reversing this choice.
Thank you again.
 
Manikm909 said:
how many more inches do i have left to go further west ...this is a 24" jack - gone from 54e to its position as photographed at 45w...its used 19 inches
do you think i can reach 58w ? or will the end of the arm fall out and cause a big kerfuffle.

also to remove this plate or not? and go with either yellow or blue position?
Click to expand...
Having looked at the first picture, if you are replacing the actuator for the recommended size to get to the far west, stick it on the other side of the polarmount since you will be further on the west side than east.
 
7mdish said:
Really thank you jeallen01 for your extensive explanation. Very clear.
So, as I must really install my new setup soon (hoping soon, I'm waiting for delivery of my new 2.4m dish), it seems that I must connect both side of the shield in motor cable.
My setup provides RC2000 controller with two actuators (for elevation correction, too), so a double motor cable must be used.
Please note that non-connection to the motor side is specified more than one time and in uppercase letters in the RC2000 user manual......
But your explanation seems totally reversing this choice.
Thank you again.
Click to expand...
That sort of "advice" prompts the thought that the controller manufacturer didn't have a very good grasp of good EMC design and construction methodologies and knew that the unit has a somewhat "fragile" EMC performance, but didn't know how-to/want-to-try to fix it, and thus wanted to hand over responsibilty any EMC-related problems to the installer/end-customer!:rolleyes:
 
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