Topics

Rotator question

John Lemay
 

'Evening all

What rotator do you use at home for the microwave bands ?

I have a Yaesu G-1000 here. It's man enough for my couple of dishes (2m and
1m) and a small yagi, but it has a backlash of about 1 degree. That's not a
lot of help when my 3cms dish has a 3dB beam-width of around 2 degrees !

Whatever I get, if I do change, will have to fit a standard Versatower head
unit.

Most makers don't specify the backlash, but I'm expecting those rotators
which use a worm gear off the motor will be better ?

A cue for tales of rotator woe perhaps ........

TIA

John G4ZTR

ian hope (2E0IJH)
 

Guessing somethink like a SPID might be better John, I know the G400/G600's we use contesting have terrible backlash.
 
Ian
2E0IJH

 
 
Sent: Tuesday, December 10, 2019 at 7:16 PM
From: "John Lemay" <john@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Rotator question
'Evening all

What rotator do you use at home for the microwave bands ?

I have a Yaesu G-1000 here. It's man enough for my couple of dishes (2m and
1m) and a small yagi, but it has a backlash of about 1 degree. That's not a
lot of help when my 3cms dish has a 3dB beam-width of around 2 degrees !

Whatever I get, if I do change, will have to fit a standard Versatower head
unit.

Most makers don't specify the backlash, but I'm expecting those rotators
which use a worm gear off the motor will be better ?

A cue for tales of rotator woe perhaps ........

TIA

John G4ZTR




 

PAUL NICKALLS
 

Hi John,

I am working on a rotator with a 100:1 worm gear driven by a stepper motor.  Not sure of the backlash at present but I intend to use it for Yagis on the tower so there is no low backlash demand.  I hope to use a similar system on a big microwave dish (2.4m) so will need good accuracy but as it will be moon tracking in one direction only the requirement for low backlash may not be too severe.

For an off the shelf soultuion you could look at:-

http://www.prosistel.net/
click on the union flag.

or
https://smart.antenna.it/
Not sure what would fit in a standard head unit but mine is like the GE 2500 NS and the gearbox has been modded to fit.

73
Paul G8AQA

On 10/12/2019 19:16, John Lemay wrote:
'Evening all

What rotator do you use at home for the microwave bands ?

I have a Yaesu G-1000 here. It's man enough for my couple of dishes (2m and
1m) and a small yagi, but it has a backlash of about 1 degree. That's not a
lot of help when my 3cms dish has a 3dB beam-width of around 2 degrees !

Whatever I get, if I do change, will have to fit a standard Versatower head
unit.

Most makers don't specify the backlash, but I'm expecting those rotators
which use a worm gear off the motor will be better ?

A cue for tales of rotator woe perhaps ........

TIA

John G4ZTR




Nick Peckett G4KUX
 

Hi John,

 

I use a ProSisTel PST61 and have had it for around 10Years now. As you may know I live in a very exposed site on the eastern edge of the Pennines and have a large antenna array and have over the years that I’ve lived here have destroyed several of what were considered “Large” rotators. The PST61 has withstood all that the Pennine winds have tried to do to it and I’ve had no mechanical failures with it. It easily resolves to 1deg with my 80Cm dish on 10Ghz and I’ve used it successfully for several years now. The only problem with it is the pot used to feed back the azimuth readout which becomes noisy on a regular basis and needs replacement. Mine currently needs this done for the third time and I intend making some modifications this time which are supposed to alleviate the problem..........We will see! You may find that the PST61 may be too large for the Versatower headunit, mine’s home built and somewhat larger, so you might have to consider the smaller PST2051 to fit.

 

Good Luck and 73s

 

Nick G4KUX

 

Sent from Mail for Windows 10

 

From: John Lemay
Sent: 10 December 2019 19:17
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Rotator question

 

'Evening all

 

What rotator do you use at home for the microwave bands ?

 

I have a Yaesu G-1000 here. It's man enough for my couple of dishes (2m and

1m) and a small yagi, but it has a backlash of about 1 degree. That's not a

lot of help when my 3cms dish has a 3dB beam-width of around 2 degrees !

 

Whatever I get, if I do change, will have to fit a standard Versatower head

unit.

 

Most makers don't specify the backlash, but I'm expecting those rotators

which use a worm gear off the motor will be better ?

 

A cue for tales of rotator woe perhaps ........

 

TIA

 

John G4ZTR

 

 

 

 

 

Chris Bartram G4DGU
 

Hello John,

I used a Prosistel 2051 to turn some big-ish HB yagis when I lived on an exposed site in NW Carmarthenshire. I wish I hadn't sold it! Like Nick, I did have problems with the direct drive of the readout pot resulting in its eventual destruction. It just needs a flexible shaft coupler eg.  a length of reinforced neoprene tube, to take-up the end float which did the damage. Nowadays I'd replace the pot with an absolute encoder and modify the control box accordingly.

73

Chris

G4DGU

John Quarmby
 

I have been using a Prosistel 2051 for nearly 10 years now and its proved its worth. It fitted the existing Altron head unit with no problem.  Like others I'm on about my third indicator pot and am considering changing to an absolute encoder and rebuilding the controller to suit, but that's not a simple task. I believe Prosistel do now make a version with a shaft encoder with 0.1 degree resolution. The PstRotatorAz software package from YO3DMU works well too.

73

John G3XDY

On 10/12/2019 23:05, Chris Bartram G4DGU wrote:
Hello John,

I used a Prosistel 2051 to turn some big-ish HB yagis when I lived on an exposed site in NW Carmarthenshire. I wish I hadn't sold it! Like Nick, I did have problems with the direct drive of the readout pot resulting in its eventual destruction. It just needs a flexible shaft coupler eg.  a length of reinforced neoprene tube, to take-up the end float which did the damage. Nowadays I'd replace the pot with an absolute encoder and modify the control box accordingly.

73

Chris

G4DGU



Chris Bartram G4DGU
 

Hello John ('XDY, this time!)

Fitting a shaft encoder into a '2051 shouldn't be a big problem. I've played with magnetic encoders while (too slowly ...) developing a new EME dish mount but I'm certain there would be no problem mechanically, with that rotator, providing the end-float problem was considered.

I'm very happy - so far! - with the OE9PMJ az-el controller, but I'm sure that for a simple azimuth controller an Arduino based approach would be pretty simple to implement.

73

Chris G4DGU

I have been using a Prosistel 2051 for nearly 10 years now and its proved its worth. It fitted the existing Altron head unit with no problem.  Like others I'm on about my third indicator pot and am considering changing to an absolute encoder and rebuilding the controller to suit, but that's not a simple task. I believe Prosistel do now make a version with a shaft encoder with 0.1 degree resolution. The PstRotatorAz software package from YO3DMU works well too.

Dominique Dehays
 

Hi John ,

I use 3  antenna rotators here . All are SPID RAK.There is one on my VHF system , one on my 432/1296/2320 system and a third one on my 10Ghz system (120cm dish).

Mechanic is perfect , but I threw away the original control box as it is useless. I have build controlers designed by F1TE and get no pb at all with accuracy.

Now there are Spid options called " HR". One can buy a kit and add it on his RAK  to get better accuracy , or buy a HR rotator. I find this solution very expensive , and not so cleaver , as they are still using incremental encoders , better to build your own controler.

73

Dom/F6DRO

John Quarmby
 

I agree the mech end of it should be fairly straightforward, its rebuilding the controller thats the more involved task, as I'm by no means a software person. If I can find a suitable app (Arduino?) already available that would help a lot - it needs 0.1 degree resolution display, software settable end stops and offset, motor speed control for start-stop, and RS232 or USB interfacing for PC control.

73

John G3XDY

On 11/12/2019 00:44, Chris Bartram G4DGU wrote:
Hello John ('XDY, this time!)

Fitting a shaft encoder into a '2051 shouldn't be a big problem. I've played with magnetic encoders while (too slowly ...) developing a new EME dish mount but I'm certain there would be no problem mechanically, with that rotator, providing the end-float problem was considered.

I'm very happy - so far! - with the OE9PMJ az-el controller, but I'm sure that for a simple azimuth controller an Arduino based approach would be pretty simple to implement.

73

Chris G4DGU

I have been using a Prosistel 2051 for nearly 10 years now and its proved its worth. It fitted the existing Altron head unit with no problem.  Like others I'm on about my third indicator pot and am considering changing to an absolute encoder and rebuilding the controller to suit, but that's not a simple task. I believe Prosistel do now make a version with a shaft encoder with 0.1 degree resolution. The PstRotatorAz software package from YO3DMU works well too.

David Redman
 

Look at the K3NG rotator controller

Lots of encoder options
I use AEAT 6012 12 bit absolute encoders with homebrew shaft mounts but other options are available
Az drive is homebrew , El drive heavy duty jackscrew.
Both encoders mounted on the rotating axis.
This is with an Arduino Mega 2560 and tracks my 3m dish to 0.1 degree positioning.
Park and stop limits fully define in software

I am not a software person and this was my first venture into Arduino but I got their with help from Doug G4DZU

If anybody wants further info then please contact me directly.


Dave
G4IDR


On Wed, 11 Dec 2019, 09:45 John Quarmby via Groups.Io, <g3xdy=btinternet.com@groups.io> wrote:
I agree the mech end of it should be fairly straightforward, its
rebuilding the controller thats the more involved task, as I'm by no
means a software person. If I can find a suitable app (Arduino?) already
available that would help a lot - it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.

73

John G3XDY

On 11/12/2019 00:44, Chris Bartram G4DGU wrote:
> Hello John ('XDY, this time!)
>
> Fitting a shaft encoder into a '2051 shouldn't be a big problem. I've
> played with magnetic encoders while (too slowly ...) developing a new
> EME dish mount but I'm certain there would be no problem mechanically,
> with that rotator, providing the end-float problem was considered.
>
> I'm very happy - so far! - with the OE9PMJ az-el controller, but I'm
> sure that for a simple azimuth controller an Arduino based approach
> would be pretty simple to implement.
>
> 73
>
> Chris G4DGU
>
>> I have been using a Prosistel 2051 for nearly 10 years now and its
>> proved its worth. It fitted the existing Altron head unit with no
>> problem.  Like others I'm on about my third indicator pot and am
>> considering changing to an absolute encoder and rebuilding the
>> controller to suit, but that's not a simple task. I believe Prosistel
>> do now make a version with a shaft encoder with 0.1 degree
>> resolution. The PstRotatorAz software package from YO3DMU works well
>> too.
>>
>
>
>



militaryoperator
 

 it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.
-------------------------



Naw, you need a bike.  Tyre off wheel, wheel over pole, big sprocket on a mount, bit of wood etc then a couple of bike chains and away you go. 

What did we ever do before rotators? 

Ben

Conrad, PA5Y
 

If you want precision and extremely good value for money you should look at Slewing drives from China, they are 10 times stronger than ANY ham rotator, easy to fit and have very low backlash. The 3 inch ones are fine for a 3m dish in a windstorm and cost about 400 USD. You can get AZ or AZ/EL, they have pulse outputs and integrated motors and gearboxes. I have ordered a 7 inch AZ/EL drive for my 4.5m dish which I will build in the Spring.

Two companies that I or friends have had dealings with are Sunslew Ltd and Coresun drive which is a new company set up by former sunslew employees.



Prosistel PST61 is strong, I have one on my 2m EME array but I have to say that the Create RC5B3 and ERC-M combination is much smoother. I have had that rotator for a very long time and it has had some big antennas on it over the years. It is as good as it has always been and I am still using the original pot. The PST61 needs care to prevent pot failure due to water damage but touch wood I seem to have found a method that prevents this. I have a SPID-RAK but I have not used it yet. I am expecting problems. Looks like another chat with Dom F6DRO is on the cards. I hope to use this with a 2m dish for 23/13 when I find another high enough mast to get the thing above the tree line.

73

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of militaryoperator via Groups.Io <Military1944@...>
Sent: 11 December 2019 11:22
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
 it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.
-------------------------



Naw, you need a bike.  Tyre off wheel, wheel over pole, big sprocket on a mount, bit of wood etc then a couple of bike chains and away you go. 

What did we ever do before rotators? 

Ben

Don Hawbaker
 

The link to the web site is not very helpful.  Exactly which model is suitable for an EME dish?  It’s not at all clear how you mount one of these things to a pole.  How big, how small?  You say $400 but I see no price list anywhere.  Shipping costs from China?  You said pulse interface.  I cannot use a pulse interface and I don’t trust them.  There are few controllers that will handle pulse.  What other interfaces are there?  Are you using just one side of a quadrature incremental output?  Is there a way to mount other position encoders?

These things are not going to be used until better sources and more information are available.

73s


On Dec 11, 2019 at 5:58 AM, <PA5Y Conrad> wrote:

If you want precision and extremely good value for money you should look at Slewing drives from China, they are 10 times stronger than ANY ham rotator, easy to fit and have very low backlash. The 3 inch ones are fine for a 3m dish in a windstorm and cost about 400 USD. You can get AZ or AZ/EL, they have pulse outputs and integrated motors and gearboxes. I have ordered a 7 inch AZ/EL drive for my 4.5m dish which I will build in the Spring.

Two companies that I or friends have had dealings with are Sunslew Ltd and Coresun drive which is a new company set up by former sunslew employees.



Prosistel PST61 is strong, I have one on my 2m EME array but I have to say that the Create RC5B3 and ERC-M combination is much smoother. I have had that rotator for a very long time and it has had some big antennas on it over the years. It is as good as it has always been and I am still using the original pot. The PST61 needs care to prevent pot failure due to water damage but touch wood I seem to have found a method that prevents this. I have a SPID-RAK but I have not used it yet. I am expecting problems. Looks like another chat with Dom F6DRO is on the cards. I hope to use this with a 2m dish for 23/13 when I find another high enough mast to get the thing above the tree line.

73

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of militaryoperator via Groups.Io <Military1944@...>
Sent: 11 December 2019 11:22
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
 it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.
-------------------------



Naw, you need a bike.  Tyre off wheel, wheel over pole, big sprocket on a mount, bit of wood etc then a couple of bike chains and away you go. 

What did we ever do before rotators? 

Ben

John Quarmby
 

Thanks Dave

Doug has also sent some useful links so I will take a look see. It looks like it will fit the bill well for what I need.

73

John G3XDY

On 11/12/2019 09:54, David Redman wrote:
Look at the K3NG rotator controller

Lots of encoder options
I use AEAT 6012 12 bit absolute encoders with homebrew shaft mounts but other options are available
Az drive is homebrew , El drive heavy duty jackscrew.
Both encoders mounted on the rotating axis.
This is with an Arduino Mega 2560 and tracks my 3m dish to 0.1 degree positioning.
Park and stop limits fully define in software

I am not a software person and this was my first venture into Arduino but I got their with help from Doug G4DZU

If anybody wants further info then please contact me directly.


Dave
G4IDR


On Wed, 11 Dec 2019, 09:45 John Quarmby via Groups.Io, <g3xdy=btinternet.com@groups.io> wrote:
I agree the mech end of it should be fairly straightforward, its
rebuilding the controller thats the more involved task, as I'm by no
means a software person. If I can find a suitable app (Arduino?) already
available that would help a lot - it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.

73

John G3XDY

On 11/12/2019 00:44, Chris Bartram G4DGU wrote:
> Hello John ('XDY, this time!)
>
> Fitting a shaft encoder into a '2051 shouldn't be a big problem. I've
> played with magnetic encoders while (too slowly ...) developing a new
> EME dish mount but I'm certain there would be no problem mechanically,
> with that rotator, providing the end-float problem was considered.
>
> I'm very happy - so far! - with the OE9PMJ az-el controller, but I'm
> sure that for a simple azimuth controller an Arduino based approach
> would be pretty simple to implement.
>
> 73
>
> Chris G4DGU
>
>> I have been using a Prosistel 2051 for nearly 10 years now and its
>> proved its worth. It fitted the existing Altron head unit with no
>> problem.  Like others I'm on about my third indicator pot and am
>> considering changing to an absolute encoder and rebuilding the
>> controller to suit, but that's not a simple task. I believe Prosistel
>> do now make a version with a shaft encoder with 0.1 degree
>> resolution. The PstRotatorAz software package from YO3DMU works well
>> too.
>>
>
>
>



Clive Elliott GW4MBS
 

As far as a mast rotator & indicator goes I used to have a 60ft Hilomast for my flyswatter. For general direction setting I had a belt driven Desyn sensor that gave a display in the shack on a 5" diam compass display. This only gave 5 deg readings, for fine tuning I used a large circular protractor that I cut the middle from & positioned over the mast diameter, with a rigid pointer I could set the heading to a degree as I had fitted a spur controller at the mast base.

Originally I turned the mast with a Selsyn motor linked to an identical unit in the shack. It was quite robust & I was told it was for controlling elevation for an AA gun on a battleship. The difficulty with that was braking & locking the mast, the intriguing thing was the wind blowing the mast transmitted an identical force to the partner Selsyn in the shack.

The best solution was when I fitted an aircraft propeller pitch motor to the base of the mast. This large heavily geared DC motor was extremely strong & could rotated very slowly if need be & reversed by swapping the polarity. I tried to find a picture online but could only find American ones, which were smaller & rather strangely said to be non-reversible.

Attached the Mk1 flyswatter 40 years ago before the reflector elevation motor & sensor was fitted.
 
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m/4m/2m/70cm/23cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!

Neil Smith G4DBN
 

Best approach is to email the manufacturer directly, this sort of kit isn't a consumer product which you can buy off a website.  They are very common and well-known across industry, but are usually furiously expensive. The new application for the tiny ones (< 8 inches) is turning solar panel arrays, and the high volume of production means the prices have fallen. The larger ones are used for cranes and in machining systems for example. They combine a precision ground bearing ring with (usually) a worm drive.


The usual approach is to fit them to a ring flange at the top of a support pole, and fix the other side to a machined flange on a 90 degree trussed elbow, then fit another to a machined flange on the vertical face of the elbow, and the other face to a flange attached to the dish/counterweight/saddle.  Nice easy fabrication/welding/machining job. There are some videos on Youtube about using them for EME systems.


A magnetic absolute encoder chip like an AS5048A can then be used (on a compliant mount) for 14-bit rotational feedback.  OK, it aneeds a bit of precision machining to make the mount, but for £15 or so for a complete PCB, chip with SPI or I2C interface and a diametrical magnet, they are excellent value. https://www.mouser.co.uk/datasheet/2/588/AS5048-EK-AB_Operation-Manual_Rev.1.3-775916.pdf


Neil G4DBN


On 11/12/2019 11:15, Don Hawbaker wrote:
The link to the web site is not very helpful.  Exactly which model is suitable for an EME dish?  It’s not at all clear how you mount one of these things to a pole.  How big, how small?  You say $400 but I see no price list anywhere.  Shipping costs from China?  You said pulse interface.  I cannot use a pulse interface and I don’t trust them.  There are few controllers that will handle pulse.  What other interfaces are there?  Are you using just one side of a quadrature incremental output?  Is there a way to mount other position encoders?

These things are not going to be used until better sources and more information are available.

73s


On Dec 11, 2019 at 5:58 AM, <PA5Y Conrad> wrote:

If you want precision and extremely good value for money you should look at Slewing drives from China, they are 10 times stronger than ANY ham rotator, easy to fit and have very low backlash. The 3 inch ones are fine for a 3m dish in a windstorm and cost about 400 USD. You can get AZ or AZ/EL, they have pulse outputs and integrated motors and gearboxes. I have ordered a 7 inch AZ/EL drive for my 4.5m dish which I will build in the Spring.

Two companies that I or friends have had dealings with are Sunslew Ltd and Coresun drive which is a new company set up by former sunslew employees.



Prosistel PST61 is strong, I have one on my 2m EME array but I have to say that the Create RC5B3 and ERC-M combination is much smoother. I have had that rotator for a very long time and it has had some big antennas on it over the years. It is as good as it has always been and I am still using the original pot. The PST61 needs care to prevent pot failure due to water damage but touch wood I seem to have found a method that prevents this. I have a SPID-RAK but I have not used it yet. I am expecting problems. Looks like another chat with Dom F6DRO is on the cards. I hope to use this with a 2m dish for 23/13 when I find another high enough mast to get the thing above the tree line.

73

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of militaryoperator via Groups.Io <Military1944@...>
Sent: 11 December 2019 11:22
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
 it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.
-------------------------



Naw, you need a bike.  Tyre off wheel, wheel over pole, big sprocket on a mount, bit of wood etc then a couple of bike chains and away you go. 

What did we ever do before rotators? 

Ben

-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>

Conrad, PA5Y
 

Well Don, these are questions that you can ask the manufacturer. Tell them what you would like to do. Say I have a 3m dish and the wind speed I would like to operate is 120km/h or whatever. There are MANY eme stations using these drives, they are MILES better than any amateur rotator. You do not have to use the pulse outputs you can fashion any system that you want and very easily. The 3 inch single axis model is here:


Dual axis is here:


You will have to specify the final rotational speed for your application and they will provide a suitable motor and planetary gearbox. They could not be easier to mount as you can see from the drawings.  I was trying to be helpful but I am not designing a system for someone. If you want strong and reliable then this is the easiest and cheapest way to do it and it is proven, The prices are available quickly by enquiry but here is a quote for airshipping for a DUAL AXIS drive suitable for a 3.7m dish for EME. 

If you ship by sea the shipping price is 1/3 of air freight approximately.

 3" Dual Axis Slewing Drive SVH3-62B-RC-24H7735-REV.A Ratio:62:1 ,Right Handed Mounting USD498.20 1
 24VDC Motor With Hall Sensor 
1 pcs Air Express to your door USD327.60

The single axis models are of course cheaper.

They are extremely well made and perform as specified.

Here is a photo from W2HRO of a 3 inch dual axis mounted, it is not exactly the same but very similar.


73

Conrad PA5Y



From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Don Hawbaker via Groups.Io <donhawbaker@...>
Sent: 11 December 2019 12:15
To: Ukmicrowaves <ukmicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
The link to the web site is not very helpful.  Exactly which model is suitable for an EME dish?  It’s not at all clear how you mount one of these things to a pole.  How big, how small?  You say $400 but I see no price list anywhere.  Shipping costs from China?  You said pulse interface.  I cannot use a pulse interface and I don’t trust them.  There are few controllers that will handle pulse.  What other interfaces are there?  Are you using just one side of a quadrature incremental output?  Is there a way to mount other position encoders?

These things are not going to be used until better sources and more information are available.

73s


On Dec 11, 2019 at 5:58 AM, <PA5Y Conrad> wrote:

If you want precision and extremely good value for money you should look at Slewing drives from China, they are 10 times stronger than ANY ham rotator, easy to fit and have very low backlash. The 3 inch ones are fine for a 3m dish in a windstorm and cost about 400 USD. You can get AZ or AZ/EL, they have pulse outputs and integrated motors and gearboxes. I have ordered a 7 inch AZ/EL drive for my 4.5m dish which I will build in the Spring.

Two companies that I or friends have had dealings with are Sunslew Ltd and Coresun drive which is a new company set up by former sunslew employees.



Prosistel PST61 is strong, I have one on my 2m EME array but I have to say that the Create RC5B3 and ERC-M combination is much smoother. I have had that rotator for a very long time and it has had some big antennas on it over the years. It is as good as it has always been and I am still using the original pot. The PST61 needs care to prevent pot failure due to water damage but touch wood I seem to have found a method that prevents this. I have a SPID-RAK but I have not used it yet. I am expecting problems. Looks like another chat with Dom F6DRO is on the cards. I hope to use this with a 2m dish for 23/13 when I find another high enough mast to get the thing above the tree line.

73

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of militaryoperator via Groups.Io <Military1944@...>
Sent: 11 December 2019 11:22
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
 it needs 0.1 degree resolution
display, software settable end stops and offset, motor speed control for
start-stop, and RS232 or USB interfacing for PC control.
-------------------------



Naw, you need a bike.  Tyre off wheel, wheel over pole, big sprocket on a mount, bit of wood etc then a couple of bike chains and away you go. 

What did we ever do before rotators? 

Ben

David Law
 

I use a 3" dual axis slew made by SunSlew. They are excellent for eme but for most other applications they would be very slow taking about 10 mins per rev (a guess I never measured it) .The pulsed output works well with the Arduino k3ng rotator controller which I got going despite never using Arduino before with help from Dave G4IDR. I reckon realistically 0.2 degree resolution with k3ng.

73 David G0LBK

Conrad, PA5Y
 

Hello Dave.

If you want a faster rotation speed then you can change the motor planetary gear ratio, this results in a reduction in output torque but it is very high by design and actually with a higher motor current (stronger motor)  this can be negated to some extent. The 'standard' ones are indeed 10 min for 360 deg but I have info for 0.5 rpm with a 30% reduction in output torque. It think that 0.3 to 0.5 rpm is just about right for contests with large narrow beamwidth antennas. Faster than that is putting stress on the support structure and you will overshoot often. 

You need to give the manufacturer information as to what you want as they have a lot of variants to offer.

73

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of David Law via Groups.Io <law1274@...>
Sent: 11 December 2019 15:52
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Rotator question
 
I use a 3" dual axis slew made by SunSlew. They are excellent for eme but for most other applications they would be very slow taking about 10 mins per rev (a guess I never measured it) .The pulsed output works well with the Arduino k3ng rotator controller which I got going despite never using Arduino before with help from Dave G4IDR. I reckon realistically 0.2 degree resolution with k3ng.

73 David G0LBK

Steve G4HTZ
 

I have a 4 year old spid rau ....I don’t know if they cured the problem of it generating hash and general noise on 6m 4m and 2m as the rotator is turned ...apparently they all done it ...but unable to confirm that ...but mine certainly does .....no noise noticeable from rotator on 23cms or 10ghz !!!
Steve G4htz

On 10 Dec 2019, at 19:17, John Lemay <john@...> wrote:

'Evening all

What rotator do you use at home for the microwave bands ?

I have a Yaesu G-1000 here. It's man enough for my couple of dishes (2m and
1m) and a small yagi, but it has a backlash of about 1 degree. That's not a
lot of help when my 3cms dish has a 3dB beam-width of around 2 degrees !

Whatever I get, if I do change, will have to fit a standard Versatower head
unit.

Most makers don't specify the backlash, but I'm expecting those rotators
which use a worm gear off the motor will be better ?

A cue for tales of rotator woe perhaps ........

TIA

John G4ZTR




--
*Steve G4HTZ
* *JO01JN*