Advice Needed Looking for DiSEqC motor for a 1.5m dish

W

Wolfclaw

Member
My Satellite Setup
Ham radio operator (SA0FAR) with a VHF/UHF setup for communication with ham radio satellites. One omnidirectional antenna setup (Az and El) with a UHF cross-yagi antenna and a VHF cross-yagi antenna. Using SDR radios for communication - SDRplay and GPredict.
My Location
Sweden
I'm planning to set up a 1.5 meter dish that needs to be controlled by a DiSEqC motor. However, all such motor on the market seem to have 1.2 meter and maximum diameter of the dish. Is that a real contraint, and why?
I'd be happy for any guidance on DiSEqC motors for larger dishes.
 
Been there and have given up.

1) In Europe, with a 120cm dish you get all relevant satellites in the KU band.
2) Those satellites or transponders you cannot receive, will require a dish of 180cm or more.
3) There is no point in having an intermediate dish of 140-150cm, which is why they are so difficult to buy. I tried to buy one and failed: no stock. Also, these are normally used over a 120cm dish for better weather reserves.
4) DiSEqC-1.2 motors are cheap and convenient. But they are only designed for dishes up to 10kg AND up to 120cm. You should not use a bigger dish, even if it weights less than 10kg, because the area will be huge and in windy days will exercise too much load over the motor.
 
Thanks, very wise words. I'll will pass on the offer I had to purchase a 150 cm dish and instead look for a 100-120 cm one.
 
I was about to purchase an aluminum offset dish 1415mm x 1300mm (a "140cm" dish). The weight is 7.390g (funny how precise they specify it, but I think it is just a less informed person who likes to use 4 digits...).

Anyway, I thought 7.4kg + LNB and eventually the support arm weight would be well under 10kg, so OK for my Motek SG2100A motor...

I was smart enough to ask ChatGPT to help with the math. The response is clear and amazing by itself:

Question:
1777282875750.webp

Reply:
1777282861671.webp
 
vma said:
I was about to purchase an aluminum offset dish 1415mm x 1300mm (a "140cm" dish)
Click to expand...
Do not miss this offer! Most likely, the person measured the dish, including rims. This in no way 140cm dish, but.... ready... this is 120cm dish. Take it without hesitation. But also check it's shape, make sure it is not warped.
 
I was speaking of a brand new dish:

1777299276940.webp

The manufacturer is not too far away from me and they do sell these antennas.

However I did not consider the price too attractive and meanwhile got elucidated on why it was a bad idea to begin with.

There is another manufacturer of antennas, well known I guess (Famaval) but they require a volume order >100 units to produce the dishes, as they don't keep stock.

This is why it is so difficult to buy them: because there is practically no demand for this size, no sat shop will order >100 units and as such you can't buy them anywhere.

Regards,
Vitor
 
Wolfclaw said:
Thanks, very wise words. I'll will pass on the offer I had to purchase a 150 cm dish and instead look for a 100-120 cm one.
Click to expand...
If it was an IRTE dish (prime focus) you could probably get away with a simple counterbalance weight on the reflector after drilling out the steel backplate. What stops most people from trying is the windloading that occurs every now and then.

For an offset reflector you have slightly less shear for the same area however there are additional loads that may not be workable on a DISEqC motor (even original Motecks) so get your angles correct and build in the exact opposite weight behind the mount.

Then test and report back.
 
vma said:
I was about to purchase an aluminum offset dish 1415mm x 1300mm (a "140cm" dish). The weight is 7.390g (funny how precise they specify it, but I think it is just a less informed person who likes to use 4 digits...).
Click to expand...
A dish that light (only 7 g) risks being blown away if you sneeze.... :->
 
Channel Hopper said:
If it was an IRTE dish (prime focus) you could probably get away with a simple counterbalance weight on the reflector after drilling out the steel backplate. What stops most people from trying is the windloading that occurs every now and then.

For an offset reflector you have slightly less shear for the same area however there are additional loads that may not be workable on a DISEqC motor (even original Motecks) so get your angles correct and build in the exact opposite weight behind the mount.

Then test and report back.
Click to expand...
I have an IRTE dish and it's been alright, even with the windy English weather we had a couple of weeks ago. I've drilled on the back plate to use it with a channel master polar mount and I'm not happy with the performance. I'm in the process of building a polar mount based on this:
.
 
The polarmount (original IRTE) lend itself well to adaption to a DiSEqC style gearbox, where the dish sits close to the pivot point. I can't see the advantage of using something from another manufacturer, with the weight of the combined mount/reflector is further forward.
 
If you need a motor for such a large dish use an actuataor. Or motor brands like Digipover Super jack,, Technomate or Cahors former Visiosat if you can stil find one- My Moteck 2500 bit it is allegedly only built f built for antenas up to 120 cm size
 
@Beli1910 has a Gibertini 1.5m dish on a DiSEqC motor, albeit with extra reinforcement:

Beli1910

Advice Needed Post in thread 'Adaptation of the GTP-1800AM 36V HH motor to Gibertini 150 cm'

Strange that the motor could not withstand the weight of the gibertini 150. It is not that heavy. The motor appears to be of poor quality. I have had the same antenna for more than 2 years without any problems - the antenna is powered by a Diqec Amiko motor. The prototype construction of the Diqec motor is indeed made and the antenna is balanced.

20230910-185426.jpg

20230910-185407.jpg
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ozumo said:
@Beli1910 has a Gibertini 1.5m dish on a DiSEqC motor, albeit with extra reinforcement:

Beli1910

Advice Needed Post in thread 'Adaptation of the GTP-1800AM 36V HH motor to Gibertini 150 cm'

Strange that the motor could not withstand the weight of the gibertini 150. It is not that heavy. The motor appears to be of poor quality. I have had the same antenna for more than 2 years without any problems - the antenna is powered by a Diqec Amiko motor. The prototype construction of the Diqec motor is indeed made and the antenna is balanced.

20230910-185426.jpg

20230910-185407.jpg
  • Like
Click to expand...
No counterweight either, so parhaps a correctly balanced 1.5m offset reflector (low down/sheltered) could be considered.
 
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