New Lnb changer

[RimaNTSS]

Assembled another table-top changer. Was thinking to lead cable inside lower feedarm, but 10mm holes are too small to let coax through them. Wish to make this changer really universal, I mean to fit any offset dish.

 

[RimaNTSS]

Made additional slot in the cogwheel, now Fibo motor turns in 2 times better accuracy, means each click turns axis about 0,9*.

 

[RimaNTSS]

Who knows (maybe @Trust1 ) if there were 3 slots made in the cogwheel, perhaps accuracy will be increased even 3 times?!

 

[John]

Who knows (maybe @Trust1 ) if there were 3 slots made in the cogwheel, perhaps accuracy will be increased even 3 times?!

Forgive me for asking Rimantss, i am not familiar with how the timing pulses are achieved with that kind of motor and i'm interested to learn more. Does by increasing the slots / decreasing the amount of metal to create three metal obstructions actually increase the pulse count ?.

 

[RimaNTSS]

@John there is optical sensor in that motor, so it counts 2 times per turn of cogwheel Instead of one originally). So, turning of axis can be stopped more frequently, in this case - 2 times more often. Perhaps my explanation is not perfect, but additional slot adds precision of positioning. In case if positioner can not cope with so fast changing of pulses, it could be the way to fix this by lowering of voltage from 36V to 24V or even 12V.

 

[John]

@John there is optical sensor in that motor, so it counts 2 times per turn of cogwheel Instead of one originally). So, turning of axis can be stopped more frequently, in this case - 2 times more often. Perhaps my explanation is not perfect, but additional slot adds precision of positioning. In case if positioner can not cope with so fast changing of pulses, it could be the way to fix this by lowering of voltage from 36V to 24V or even 12V.

.... thanks for that, re: pulse counts, my 36volt jack on the 1.8 does not have a high pulse count ..... my Jaeger 1224 that i use on my 1.2 has some thing like 11 pulses per 1deg which made it nice for nudging the dish for max signal. The 36volt jack's accuracy is just about fine for Cband and Ku nudging but when it comes to Ka signals it's just not accurate enough and you can easily miss the peak of the signal due to over-shooting. I will have to look into increasing the pulse count on it when i get time. ;)

 

[RimaNTSS]

Agree with you @John , firstly when we have think we got time we always have another priorities... Secondly, in case of polar-mount, precision of its turning for Ka-band can be critical (Ive never used K-band, so can not say it from personal experience). Thirdly, it is not known how precision of LNB changer will influence reception, I men whether 0?9* precision is enough for Ka-band?

 

[Trust]

View attachment 90828 @ John , to use that fibo motor for usals (with the electronic of a SG2100) it has to make 37 pulses for one degree arc .
More holes in that gear provide more ( optical ) pulses , so i made 7 holes in that gear .
The SG2100 electronic is designed to work with high speed counting , i'm not shure a regular positioner or V-box can handle those short pulses from a 5 mm hole

 

[John]

Agree with you @John , firstly when we have think we got time we always have another priorities... Secondly, in case of polar-mount, precision of its turning for Ka-band can be critical (Ive never used K-band, so can not say it from personal experience). Thirdly, it is not known how precision of LNB changer will influence reception, I men whether 0?9* precision is enough for Ka-band?

Your right about changer accuracy, especially for Ka band signals. My changer is loaded with C, Ku & Ka lnb's , i always have my analyser in circuit when changing bands. Changing from C to Ku is ok and you can see the signals without too much problem. Change bands to Ka and there's nothing there ..... i have to use the assistance from the analyser by nudging E-W or up/down on the elevation jack to see the signals again. Were only talking about the slightest movement to regain the signals, it's that precise. it must be a nightmare on even larger dishes with even narrower beamwidths.
Edit: I perhaps should also say that accurate arc tracking is a must, mine is not 100% so adds to my problems

 

[John]

View attachment 90828 @ John , to use that fibo motor for usals (with the electronic of a SG2100) it has to make 37 pulses for one degree arc .
More holes in that gear provide more ( optical ) pulses , so i made 7 holes in that gear .
The SG2100 electronic is designed to work with high speed counting , i'm not shure a regular positioner or V-box can handle those short pulses from a 5 mm hole

View attachment 90826 View attachment 90827View attachment 90829

Ahh, thank you. I understand a bit better now.

 

[scopus]

Your right about changer accuracy, especially for Ka band signals. My changer is loaded with C, Ku & Ka lnb's , i always have my analyser in circuit when changing bands. Changing from C to Ku is ok and you can see the signals without too much problem. Change bands to Ka and there's nothing there ..... i have to use the assistance from the analyser by nudging E-W or up/down on the elevation jack to see the signals again. Were only talking about the slightest movement to regain the signals, it's that precise. it must be a nightmare on even larger dishes with even narrower beamwidths.
Edit: I perhaps should also say that accurate arc tracking is a must, mine is not 100% so adds to my problems

From my experience so far with the Trust designed LNB changer, I have not had a problem with it landing on ka, always been spot on, even after changing from C to ku back to Ka, even the my superjack heavy duty jobbie for moving the dish has not given me a problem using a Moteck V box.
Probably that Titanium controller you are using John, loads on the forums about pulse counts being inaccurate, although I know you have done a mod.
I recently changed my V box to the Moteck after problems with counts on the Superjack one I was using, the Motek for me is always spot on, runs a damn sight cooler than the Superjack too!

 

[John]

From my experience so far with the Trust designed LNB changer, I have not had a problem with it landing on ka, always been spot on, even after changing from C to ku back to Ka, even the my superjack heavy duty jobbie for moving the dish has not given me a problem using a Moteck V box.
Probably that Titanium controller you are using John, loads on the forums about pulse counts being inaccurate, although I know you have done a mod.
I recently changed my V box to the Moteck after problems with counts on the Superjack one I was using, the Motek for me is always spot on, runs a damn sight cooler than the Superjack too!

was the one i gave you a Motek ?

 

[scopus]

was the one i gave you a Motek ?

Yep, badged as Technomate but it's really a Moteck.

 

[John]

Yep, badged as Technomate but it's really a Moteck.

.... did you manage to get a remote for it ?

 

[scopus]

.... did you manage to get a remote for it ?

I did indeed John.

 

[Archive-8]

So is the technomate positioner worth a shot? As my allsat positioner keeps miss counting. And as a result I have to allways move the dish manually with the L+R button.

And I have a similar problem to @John in finding the ka signals.

 

[RimaNTSS]

I have a question: why remote for positioner is needed? I have several remotes laying around, never used them and did not feel the need.

 

[RimaNTSS]

If somebody needs this remote, let me know. You pay shipping.

 

[scopus]

If somebody needs this remote, let me know. You pay shipping.

I'll have that Rimnants, how much for the postage?

 

[scopus]

I have a question: why remote for positioner is needed? I have several remotes laying around, never used them and did not feel the need.

I just find it easier to nudge the dish etc.. with the remote rather than using the receiver menu, just my personal choice.