The C-band Tin-Dish challenge

B

blademedia

Member
Messages
1,942
My Satellite Setup
Sky
My Location
UK
The early Patriots were awkward in the extreme to align, mainly down to the weight being too far forward, and the Prodelin 3.4 and 3.7m have a 70 degree arc only, with a preference of east or west motor setup only.
They track the arc and get the job done, must admit you cant beat custom build, seems a shame for such a nice dish that s-bands owns to be sat in a shed due to no mount, options are thin on the ground for getting one, 6/7 grand new are maybe a bargain @ 6 hundred, at the end of the day its s-bands choice :)
 
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Messages
27,664
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK South
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Messages
27,664
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK South
They track the arc and get the job done, must admit you cant beat custom build, seems a shame for such a nice dish that s-bands owns to be sat in a shed due to no mount, options are thin on the ground for getting one, 6/7 grand new are maybe a bargain @ 6 hundred, at the end of the day its s-bands choice :)
I looked at the auction link and really, there is no information to suggest what is for sale will do the job.

I have parts of an Ajak and Patiot here if they are of any use, but unless my memory is playing tricks, the later IRTE polar mount was used on all designs from 1.2 through to their 3m solid dishes, and there are plenty of them out there.

Nothing will really replace a EL/AZ and king post though, except a fluid gimbal type incorporating zero backlash.

 
Last edited:
B

blademedia

Member
Messages
1,942
My Satellite Setup
Sky
My Location
UK
I looked at the auction link and really, there is no information to suggest what is for sale will do the job.

I have parts of an Ajak and Patiot here if they are of any use, but unless my memory is playing tricks, the later IRTE polar mount was used on all designs from 1.2 through to their 3m solid dishes, and there are plenty of them out there.

Nothing will really replace a EL/AZ and king post though, except a fluid gimbal type incorporating zero backlash.
@s-band This might be of interest to you, reading elsewhere this
Code:
http://www.ebay.co.uk/itm/Satellite-Dish-professional-3-6-metres-/291941979677?hash=item43f919161d:g:CYAAAOSw8vZXMOUk
comes with a mount doesn't say what type but its a tracking mount, even if you don't use the dish it comes with still a cheap mount
Someone on another forum made enquiry, that's a nice offer hope you have something to help :)
 
Last edited:
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Messages
27,664
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK South
They track the arc and get the job done, must admit you cant beat custom build, seems a shame for such a nice dish that s-bands owns to be sat in a shed due to no mount, options are thin on the ground for getting one, 6/7 grand new are maybe a bargain @ 6 hundred, at the end of the day its s-bands choice :)
Ah, but they dont, the - early - Patriot was notorious for distorting the upper bearing retention bracket out of true position, meaning the focal point would change depending on whether you arrived at the satellite from the east, or west. Including an elevation motor is a fix but no professional system should have this flaw in the first place. A good weight distribution also removes the need for heavy counterweights, and the take up points built into the design.

The further the two bearings are the better of course , and some designs have used a similar arangement to car suspension, or use taper bearings which have an infinitely better resistance to wear over ball races.
 
B

blademedia

Member
Messages
1,942
My Satellite Setup
Sky
My Location
UK
Ah, but they dont, the - early - Patriot was notorious for distorting the upper bearing

A good weight distribution also removes the need for heavy counterweights, and the take up points built into the design.
Yes that was due to it being unbalanced as you mentioned, still tracked the arc ok but you needed to change the bearings often,

I cant agree more, my mount is being made with counter balance built in, before I drill the hole to hold it on the king post, I will attache the dish to mount, place it at 52.0406° find its balance mark and drill, that way I have a perfectly balanced mount,
 
B

blademedia

Member
Messages
1,942
My Satellite Setup
Sky
My Location
UK
Made me laugh that comment, think he was taking the :-peepee:)
 
S

s-band

Specialist Contributor
Messages
812
My Satellite Setup
1.5m IRTE PF, Octagon OSLO external Ref., TBS6983,
Various L, S, C, X & Ka bits. 1.2m S/X/Ku/Ka Prodelin on Az-El
My Location
SE UK
I moved the scalar about 15mm back by fixing the tripod legs to the front of it. To find Paksat 1R again, I set the elevation and pointed the dish in vaguely the right direction. 40E is very obvious so once that was found, I nudged the dish a bit and found the beacons easily this time. I don't know why I missed them before, I might have set the wrong polarisation.
paksat_1r_3702.9h.gif paksat_1r_4196.5h.gif
I peaked the dish on 4196.5H. I then scanned using Crazyscan
38e_cs.JPG
Then I used EBSPro on 3818 to peak the feed and scalar positions and then re-peaked the dish and got this scan result:
38E_peaked_on_3918.JPG
Some extra TPs compared to the first scan but some missing. 3984 was a dB or so lower as well so I re-peaked for SNR on EBS on 3984 and got:
38E_peaked_on_3984.JPG
3818 now gone but I could lock it manually. I was using 1MHz scan steps with 4MHz width. I couldn't lock anything on horizontal although I could see them on the spectrum.

I was quite surprised to get 3728V in view of the bit rate. Here's a capture of Geo News which seems to be a slide show with voice over:
geo_news_3728V_38E.JPG

Since we've talked about it, here's AJK-TV on 3984V
AJK-TV_3984v.JPG

As CH said, there appears to be some frequency dependence associated with fine tweaks of dish and feed alignment hence losing 3818 when 4184 was peaked. So, the tin dish didn't do too badly in the end.


2.4_34.jpg
 
Last edited:
John

John

Enthusiast.
Messages
2,264
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 moved the scalar about 15mm back by fixing the tripod legs to the front of it. To find Paksat 1R again, I set the elevation and pointed the dish in vaguely the right direction. 40E is very obvious so once that was found, I nudged the dish a bit and found the beacons easily this time. I don't know why I missed them before, I might have set the wrong polarisation.
View attachment 101081 View attachment 101082
I peaked the dish on 4196.5H. I then scanned using Crazyscan
View attachment 101084
Then I used EBSPro on 3818 to peak the feed and scalar positions and then re-peaked the dish and got this scan result:
View attachment 101085
Some extra TPs compared to the first scan but some missing. 3984 was a dB or so lower as well so I re-peaked for SNR on EBS on 3984 and got:
View attachment 101086
3818 now gone but I could lock it manually. I was using 1MHz scan steps with 4MHz width. I couldn't lock anything on horizontal although I could see them on the spectrum.

I was quite surprised to get 3728V in view of the bit rate. Here's a capture of Geo News which seems to be a slide show with voice over:
View attachment 101087

Since we've talked about it, here's AJK-TV on 4184V
View attachment 101088

As CH said, there appears to be some frequency dependence associated with fine tweaks of dish and feed alignment hence losing 3818 when 4184 was peaked. So, the tin dish didn't do too badly in the end.


View attachment 101089


Result ..... better figures than off my 1.8 CM at a fraction of the cost. Those beacons look well up now G.
Do you fancy doing the 2" wide sticky back Alu tape over the petal joint's and grab yourself a knats more sig possibly
 
Channel Hopper

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Messages
27,664
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK South
Result ..... better figures than off my 1.8 CM at a fraction of the cost. Those beacons look well up now G.
Do you fancy doing the 2" wide sticky back Alu tape over the petal joint's and grab yourself a knats more sig possibly
The gap between petals is well under the wavelength of reception, however it might be worth doing a 'shakedown' with the dish on its maximum elevation, (undoing the bolts between the reflectors sufficiently and shaking repeatedly until all the surfaces are within a mm , then retightening)

Realigning the feed so it is centred to the dish reflector -boresighting- after this should make the dish sing in tune (unlike Adele) at C-Band.
 
John

John

Enthusiast.
Messages
2,264
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 moved the scalar about 15mm back by fixing the tripod legs to the front of it. To find Paksat 1R again, I set the elevation and pointed the dish in vaguely the right direction. 40E is very obvious so once that was found, I nudged the dish a bit and found the beacons easily this time. I don't know why I missed them before, I might have set the wrong polarisation.
View attachment 101081 View attachment 101082
I peaked the dish on 4196.5H. I then scanned using Crazyscan
View attachment 101084
Then I used EBSPro on 3818 to peak the feed and scalar positions and then re-peaked the dish and got this scan result:
View attachment 101085
Some extra TPs compared to the first scan but some missing. 3984 was a dB or so lower as well so I re-peaked for SNR on EBS on 3984 and got:
View attachment 101086
3818 now gone but I could lock it manually. I was using 1MHz scan steps with 4MHz width. I couldn't lock anything on horizontal although I could see them on the spectrum.

I was quite surprised to get 3728V in view of the bit rate. Here's a capture of Geo News which seems to be a slide show with voice over:
View attachment 101087

Since we've talked about it, here's AJK-TV on 3984V
View attachment 101088

As CH said, there appears to be some frequency dependence associated with fine tweaks of dish and feed alignment hence losing 3818 when 4184 was peaked. So, the tin dish didn't do too badly in the end.


View attachment 101089



@sband ....
Just going back to your earlier post Graham re: how you said your Norsat was letting 22KHz through etc i thought i would get my Norsat 3520 pll swapped out on the H/V only lump and have a bit of a comparison and noted this behaviour on the analyser.
Using 18v supply with 22KHz turned OFF there was good lock achieved ...... turn the 22KHz ON and the analyser instantly lost lock.
Using 15v supply with 22KHz ON did not affect anything and retained solid lock.
 

Attachments

John

John

Enthusiast.
Messages
2,264
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.
Both @sband & myself have been doing a bit of comparison work between the Zinwell lnbf and Norsat Cband lnb's ..... this is a bit more info for sband that might be found as useful.

Nothing highly technical on the set-up , just basic readings off the analyser..... signal is from 55°West--3802H.
The yellow trace Graham is the Zinwell + AV-Comm barrel, the white trace is the saved trace from the Norsat 3520.
At one point the Zinwell + barrel was only just a fraction behind the C/N figure of the Norsat ..... the Norsat peaking at 8.1dB, the Zinwell peaking at 7.9 - 8dB.
Zinwell has the higher gain as shown in the trace but they both track pretty accurately to each other.
This Zinwell does not do too bad on performance considering it has a barrel in the signal path as well, where the Norsat is just straight in unobstructed to the probe.
 

Attachments

S

s-band

Specialist Contributor
Messages
812
My Satellite Setup
1.5m IRTE PF, Octagon OSLO external Ref., TBS6983,
Various L, S, C, X & Ka bits. 1.2m S/X/Ku/Ka Prodelin on Az-El
My Location
SE UK
The gap between petals is well under the wavelength of reception, however it might be worth doing a 'shakedown' with the dish on its maximum elevation, (undoing the bolts between the reflectors sufficiently and shaking repeatedly until all the surfaces are within a mm , then retightening)
Realigning the feed so it is centred to the dish reflector -boresighting- after this should make the dish sing in tune (unlike Adele) at C-Band.
It think that the petal alignment is quite good. I used drifts to align the holes and a flat edge to make sure the front of the petals were level. Boresighting is worthwhile.

your Norsat was letting 22KHz through etc i thought i would get my Norsat 3520 pll swapped out on the H/V only lump and have a bit of a comparison and noted this behaviour on the analyser.
Using 18v supply with 22KHz turned OFF there was good lock achieved ...... turn the 22KHz ON and the analyser instantly lost lock.
Using 15v supply with 22KHz ON did not affect anything and retained solid lock.
Further evidence that the regulator is not good. Have you taken the lid off to see what it uses?
It might be worth adding your findings to this thread: Norsat 3220 C band LNB Warning

Both @sband & myself have been doing a bit of comparison work between the Zinwell lnbf and Norsat Cband lnb's ..... this is a bit more info for sband that might be found as useful.
Hmm, I wish my Zinwell was like that. I still need to do a sky/ground noise test to confirm it is duff.

Back to Paksat 1R. I was wondering about the variations noted on the TV sigs so I left the tracking RX on 3702.9H for a few hours. The beacon level stayed within the error range of the RX (~+/-0.3dB ) Unfortunately I wasn't able to leave it running for a full 24hrs.

I'm not sure I'll do much more with the Fortec. It's getting in the way a bit now and I want to use the space to do stuff on the other 2 dishes. I'd like to move it around the front of the house, where it could "see" the western sats. However, the path is blocked at the moment.
 
S

s-band

Specialist Contributor
Messages
812
My Satellite Setup
1.5m IRTE PF, Octagon OSLO external Ref., TBS6983,
Various L, S, C, X & Ka bits. 1.2m S/X/Ku/Ka Prodelin on Az-El
My Location
SE UK
It's hard to adjust the elevation manually so I added a jack. It is a very cheap 24" one but works ok. The angle is far from ideal when pointing below 15 degrees. However, with the jack running from 12V it is easy to control and I was pleasantly surprised that it could bring the dish back from about 8 degrees, even at the low voltage. Anything above about 18V is too fast. It would be better to mount the jack on a structure further back from the dish but it works as it is.

elevation_DSC1698 copy.jpg elevation_DSC1700 copy.jpg
 
S

s-band

Specialist Contributor
Messages
812
My Satellite Setup
1.5m IRTE PF, Octagon OSLO external Ref., TBS6983,
Various L, S, C, X & Ka bits. 1.2m S/X/Ku/Ka Prodelin on Az-El
My Location
SE UK
It works well on X band. The side lobes are not wonderful and if you look at the shadow, it was not quite centred when peaked on sun noise. More tweaking required.
The scan is from 52.5W WGS-5

2.4_X_edit_DSC1764 copy.jpg X_feed_lna_DSC1774 copy.jpg sun_DSC1770 copy.jpg 52.5W.jpg
 
Last edited:
A

amdade

Regular Member
Messages
22
My Satellite Setup
1.5m C Band, 1.2m Channel Master offset KU, Technomate TM-6902
My Location
Norfolk, UK
Hi Guys
Just seen this thread, good work very interesting, the pallet mount looks very interesting. Mine is still working well, have it currently parked on 40.5W, scans 214 channels. ESPN HD all good.

The focal length I calculated from measuring my fortec was 923mm. The scalar ring is an old Chaparral seems to out perform the ones that come with the LNBF from Titanium. I moved the feed horn support out a little by drilling some different holes in the rim. Its a 0.38 f/d so i think the feed horn should be 13mm ish proud of the scalar rings. (correct me if Im wrong )

One interesting thing is the dielectric plate. I seem to get better performance from using the groves that are 90 degrees different than the ones that put the plate in the middle of the 2 probes. If you see what I mean :-)
 

Attachments

John

John

Enthusiast.
Messages
2,264
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.
IMG_4807.. reduced.....jpg
Hi Guys
Just seen this thread, good work very interesting, the pallet mount looks very interesting. Mine is still working well, have it currently parked on 40.5W, scans 214 channels. ESPN HD all good.

The focal length I calculated from measuring my fortec was 923mm. The scalar ring is an old Chaparral seems to out perform the ones that come with the LNBF from Titanium. I moved the feed horn support out a little by drilling some different holes in the rim. Its a 0.38 f/d so i think the feed horn should be 13mm ish proud of the scalar rings. (correct me if Im wrong )

One interesting thing is the dielectric plate. I seem to get better performance from using the groves that are 90 degrees different than the ones that put the plate in the middle of the 2 probes. If you see what I mean :)



Agree what you say about the difference in scalar rings, the pucka Chaparral / ADL ones are far better designed. You can see the difference that's gone into the designs by looking at the two varieties iv'e shown in the pictures.
My scalar ring ended up at about 22mm back from the front lip of the feed barrel on my 2.2 PF. If you really wanted to tune the nuts off the system try using an extra cheap scalar ring mounted to the rear of the front scalar ring, extend the feed support arms a little and attach the cheap scalar ring to them. This way you can tune the lnb barrel for optimum without the front scalar -- clamp it off onto the lnb--then tune the free quality scalar on the barrel for optimum again in whatever part of the band you desire. A bit of work involved granted but you would be surprised with the added gained 1/2 a dB or so you can gain on very low level signals.
Post us as many pics of your trials etc please ... we love pictures on here lol.
......................................................................................................................................................................................................................................................................................................................................................................

IMG_4805 ... reduced...jpg IMG_4893.JPG
 
Top