C-band Servo Polarity Mod

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
@John How do you fix servo motor in the bracket? Is it just stuck inside? Is not that little bit overkill with strength of the bracket for the motor? If you have exact drawing of needed bracket, I could try to make one out of 2mm INOX.


The close proximity of the camera makes it look bigger than it really is ........ just knocked it up out of available bits and bobs out of the scrap bin.
The motor is a snug fit but has also got a very thin layer of silicone around it, when it is fitted to the lnb cradle spindle coupling and tested for functionality i will determine if it needs any further refinement then. Would look nice in INOX tho
 

Attachments

  • C-band servo + bracket ....reduced...jpg
    C-band servo + bracket ....reduced...jpg
    608.1 KB · Views: 49

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
This is the start of the coupling device between servo motor and lnb cradle spindle
76581-6556899c96516332feff41bbe61fbabb.jpg

Cheap and simple to make.
 

Attachments

  • SERVO COUPLING... reduced....jpg
    SERVO COUPLING... reduced....jpg
    934.4 KB · Views: 45

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
.... select the right size and modify to suit
76582-ce477e0aa4dec6ed9dc2603a6a0dad8a.jpg
76583-c339d7e63f64c3f4e28fb45ad88f1d38.jpg
76584-231114ad8ddc4091f47814d5af986fb1.jpg


Heat shrink and couple together for temp test later
76585-cc1177c393d53ceae7b240ad04b41aaf.jpg
 

Attachments

  • SERVO COVER.. reduced.....jpg
    SERVO COVER.. reduced.....jpg
    522 KB · Views: 51
  • SERVO COUPLING... reduced......jpg
    SERVO COUPLING... reduced......jpg
    444.9 KB · Views: 43
  • SERVO COUPLING... reduced.......jpg
    SERVO COUPLING... reduced.......jpg
    281.4 KB · Views: 46
  • SERVO COUPLING... reduced.........jpg
    SERVO COUPLING... reduced.........jpg
    547.1 KB · Views: 49

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
... Bench testing done and seems to be ok. Final securing of servo motor bracket needed, fit weather shield over motor and bearing assembly and fit onto dish when it gets a bit more bearable working outside.

Test video's here ...
and here ....
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
EEkkkk first vid link duff, will check it out ...

try this ...
 
Last edited:

nelson_b

Contributor
Joined
Jul 27, 2008
Messages
1,962
Reaction score
2,026
Points
113
Age
73
My Satellite Setup
Strong 4375 driving a 2.4 m Channel Master dual focus offset + Invcom Quad C120 K/U l.n.b. + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 - Octagon SX88+Optima - GT Media V7 - HD receivers. + other dishes currently in use - Antique 3.0 m Prodelin P.F. - Channel Master 1.8 m offset - Channel Master. 1.2 m.
My Location
North West Yorkshire - near Lancashire & Cumbria borders.
o.k. @John
as promised some pics of the recently purchased AV-Comm ... and some details
203 mm length
71 mm external diameter - both ends
63 mm internal diameter front
60 mm internal diameter rear
38 mm from front to start of 1st step
25 mm from end of last step to reduction in rear section
30 mm length of reduced rear section

front.jpg rear.jpg side.jpg
 
Last edited:

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
o.k. @John
as promised some pics of the recently purchased AV-Comm ... and some details
203 mm length
71 mm external diameter - both ends
63 mm internal diameter front
60 mm internal diameter rear
38 mm from front to start of 1st step
25 mm from end of last step to reduction in rear section
30 mm length of reduced rear section

View attachment 90960 View attachment 90961 View attachment 90962



Thanks for that Nelson, it looks a well made item and more beefier wall thickness than my two types..... wether it's just the camera close proximity ??. Mine are in the freezing workshop at the moment but i will do some comparison measurements tomorrow for sure.
 

nelson_b

Contributor
Joined
Jul 27, 2008
Messages
1,962
Reaction score
2,026
Points
113
Age
73
My Satellite Setup
Strong 4375 driving a 2.4 m Channel Master dual focus offset + Invcom Quad C120 K/U l.n.b. + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 - Octagon SX88+Optima - GT Media V7 - HD receivers. + other dishes currently in use - Antique 3.0 m Prodelin P.F. - Channel Master 1.8 m offset - Channel Master. 1.2 m.
My Location
North West Yorkshire - near Lancashire & Cumbria borders.
Thanks for that Nelson, it looks a well made item and more beefier wall thickness than my two types..... wether it's just the camera close proximity ??. Mine are in the freezing workshop at the moment but i will do some comparison measurements tomorrow for sure.


could be the camera - close up shot - its a bit uneven in its thickness but between 3.5 mm and 4 mm at the front and 5 mm to 5.5 mm at the back .. a chunky thing for sure .. :)
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
could be the camera - close up shot - its a bit uneven in its thickness but between 3.5 mm and 4 mm at the front and 5 mm to 5.5 mm at the back .. a chunky thing for sure .. :)


very chunky indeed, can't remember mine being 5mm or so at the back end. Nice and thick material though if you ever needed to machine any of the surfaces to suit personal modding requirements
 

Captain Jack

Burnt out human
Joined
Oct 21, 2006
Messages
11,797
Reaction score
7,980
Points
113
My Satellite Setup
See signature
My Location
North Somerset
So would the offset feedhorn fit straight on? And how would the lnb attach on the other end?
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
So would the offset feedhorn fit straight on? And how would the lnb attach on the other end?


.... just about to go out into the workshop to measure my poloriser barrels for Nelson CJ so a quick answer first .... Look at post 33 pics, if you are going to use it as a static L/R circ only installation with a lnbf of your choice , then join all three together. Some machining of the outer / inner dimensions of the individual units might be required to establish this, as i had to do.
OR; .... as in same post, image 2629, insert the pol tube where the black mounting clip is shown so you have this final combination ..... Conical scalar > Poloriser tube > single C-band feed > C-band lnb.
The machining of parts will probably apply here as well. The scalar and poloriser tube remain in a fixed static position and only the single feed/lnb are either manually or motorised rotated in the end of the poloriser barrel to give you the L / R or H/V choice. Hope this helps .... off to the freezing workshop now
 

nelson_b

Contributor
Joined
Jul 27, 2008
Messages
1,962
Reaction score
2,026
Points
113
Age
73
My Satellite Setup
Strong 4375 driving a 2.4 m Channel Master dual focus offset + Invcom Quad C120 K/U l.n.b. + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 - Octagon SX88+Optima - GT Media V7 - HD receivers. + other dishes currently in use - Antique 3.0 m Prodelin P.F. - Channel Master 1.8 m offset - Channel Master. 1.2 m.
My Location
North West Yorkshire - near Lancashire & Cumbria borders.
So would the offset feedhorn fit straight on? And how would the lnb attach on the other end?

No - C.J. - not a straight fit ... but managed to remove enough metal from the feed to get it on there (just).
for temporary testing i used a empty can to sleeve / join the l.n.b.f. to the AV-Comm. -- poor weather stopped me though ... to be continued at some point ....
feed 1.jpg feed 2.jpg feed 3.jpg
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
o.k. @John
as promised some pics of the recently purchased AV-Comm ... and some details
203 mm length
71 mm external diameter - both ends
63 mm internal diameter front
60 mm internal diameter rear
38 mm from front to start of 1st step
25 mm from end of last step to reduction in rear section
30 mm length of reduced rear section

View attachment 90960 View attachment 90961 View attachment 90962


@ Nelson, the two types of barrel iv'e got are the 'AV-Comm' and the 'National ADL'.
The AV-Comm has exactly the same dimensions to yours apart from internal diameter rear which is 60mm on yours, mine is 63mm, as the front.

The 'National ADL' is 35mm from front to start of first step.
The overall length of the AV-Comm is the same, 203mm. The National ADL is 163mm.
 

otokoc

Member
Joined
Feb 8, 2009
Messages
40
Reaction score
52
Points
18
Age
43
My Satellite Setup
DM920HD
prodelin1244
My Location
Balikesir,Turkey
this my avcomm with testing esx241,bsc421,c1wpll and zinwell. i have best gain avcomm and zinwell lnb
 

Attachments

  • 41.jpg
    41.jpg
    492.2 KB · Views: 52
  • 43.jpg
    43.jpg
    341.7 KB · Views: 51
  • 44.jpg
    44.jpg
    263.1 KB · Views: 51
  • 45.jpg
    45.jpg
    349.4 KB · Views: 53
  • 46.jpg
    46.jpg
    341.7 KB · Views: 53
  • 49.jpg
    49.jpg
    538 KB · Views: 53
  • 63.jpg
    63.jpg
    236.4 KB · Views: 56

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
this my avcomm with testing esx241,bsc421,c1wpll and zinwell. i have best gain avcomm and zinwell lnb


thanks for the information otokoc, very interesting. Glad to see that others have to have their units machined. :D:D
 

nelson_b

Contributor
Joined
Jul 27, 2008
Messages
1,962
Reaction score
2,026
Points
113
Age
73
My Satellite Setup
Strong 4375 driving a 2.4 m Channel Master dual focus offset + Invcom Quad C120 K/U l.n.b. + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 - Octagon SX88+Optima - GT Media V7 - HD receivers. + other dishes currently in use - Antique 3.0 m Prodelin P.F. - Channel Master 1.8 m offset - Channel Master. 1.2 m.
My Location
North West Yorkshire - near Lancashire & Cumbria borders.
@ Nelson, the two types of barrel iv'e got are the 'AV-Comm' and the 'National ADL'.
The AV-Comm has exactly the same dimensions to yours apart from internal diameter rear which is 60mm on yours, mine is 63mm, as the front.

The 'National ADL' is 35mm from front to start of first step.
The overall length of the AV-Comm is the same, 203mm. The National ADL is 163mm.

Thanks- John- for the details ...
i wonder why the rear diameter should be reduced to 60 mm ? ... cant see any advantages :(
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
Thanks- John- for the details ...
i wonder why the rear diameter should be reduced to 60 mm ? ... cant see any advantages :(



I'm not a 100% sure but it might be to do with frequency range ??? don't really know. The barrels on different lnbf's are also slightly tapered , well mine are :D
 

Captain Jack

Burnt out human
Joined
Oct 21, 2006
Messages
11,797
Reaction score
7,980
Points
113
My Satellite Setup
See signature
My Location
North Somerset
I find it annoying that you would spend £200 on the barrel and the having to machine it down to fit industry standard equipment sizes....
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
I find it annoying that you would spend £200 on the barrel and the having to machine it down to fit industry standard equipment sizes....


Too true, i recon it wouldn't be too much of a job to home brew one of those
 

John

Enthusiast.
Joined
Jan 1, 2000
Messages
3,726
Reaction score
5,528
Points
113
Location
North Nottinghamshire.
My Satellite Setup
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
My Location
North Nottinghamshire.
Well .....
been doing a bit of evaluation between the old Cband Chaparral servo / new motorised project / single feed+scalar ring choice.
Briefly, the new motorised polarity servo unit + Primesat lnb for H/V ...LHC/RHC gives around 2dB better signal performance over the old unit. The use of just a single feed + Norsat pll lnb + conical scalar used on either H or V has a slightly better performance, 1/2 a dB or so, as you would expect. Here's a surprise ..... change the conical scalar on the single feed to a Cone scalar and got at least 1/2 db increase ... only small increases but every bit helps when trying to squeeze the last drop out of a 1.8 CM system.
Note: Everything in the pics are in prototype mode, a tidy up of all brackets, nuts & bolts, cables, earthing etc to be done in warmer weather. :-)
 

Attachments

  • C-band servo... reduced...jpg
    C-band servo... reduced...jpg
    654.1 KB · Views: 65
  • Cband scalar comparison....reduced..jpg
    Cband scalar comparison....reduced..jpg
    603.9 KB · Views: 63
  • C-band servo..... reduced...jpg
    C-band servo..... reduced...jpg
    706.7 KB · Views: 65
Last edited:
Top