Replacement System

[smiffie]

After the recent failure of my Jaeger 99G H to H mount I decided to do a complete reinstall with a new dish and motor, I also took the opportunity to replace the 18" painted T and Ks with 12" galvanised steel mounts. I have however re-used the 2" galvanised steel scaffold pole, V bolts, LNB and all the cables. The new motor is great, very fast and really quiet, I did have a bit of a problem setting it up as the VBox needs the remote in order to clear the limits, which wasn't working as it hasn't been used in about ten years, so I had to get the soldering iron out to repair it!

I decided to go for a smaller dish than the ISS 105cm I have, as I've worked out that 85cm is sufficient to recieve the weak signals from 16E and 5E in my location. The replacement is made by Maxx digital and whilst I ordered a 90cm, the reflector dimensions are 100cmX90xcm so I'm classing it as a 95cm. I'm really pleased with the quality of the dish, its nice and light and has a similar construction to a Triax with the strong wide extruded aluminium LNB arm, signal levels are great with no discernible difference on 5E and 16E when compared with the 105cm. The exception is that levels seem to be down on 28E/23E and 19E.

I believe I'm tracking the arc ok as I have 100% (16.9b from Euro Star at 42E and 100% (16.6d on BBC World at 1W and as I said 5E/16E are fine. Initially Channel 5 HD on 28E was showing 66% but after sliding the LNB away from the dish in its bracket its upto 77% which is still below what I would expect for 28E. Measuring the levels at 28E with a meter also seem to indicate the signal is peaked and the arc tracking is OK. I thought it may be a line of sight problem, but dishpointer does not seem to support this idea. Looking at the levels I don't think I'll ever loose the signal from those satellites due to adverse weather but it is a bit of a puzzle.

 

[smiffie]

I know Dishpointer shouldn't be taken as gospel, but taken as a guideline, there doesn't appear to be a line of sight issue.

 

[A nonymous]

Never take the levels from a Dreambox as Gospel as nine times out of ten they are wrong.

I get totally different readings from my DM7020Si, my IPBox 250s and my FS1 meter from the same dish and cable.

Have you considered that the levels are bound to be less as your using a smaller dish? Are the lower readings on horizontally polarised channels or Vertical ones?

If its horizontal ones the smaller dish will be the issue.

Nano

 

[satelliteman]

Certainly a nice setup anyway smiffie.

 

[smiffie]

Never take the levels from a Dreambox as Gospel as nine times out of ten they are wrong.

I get totally different readings from my DM7020Si, my IPBox 250s and my FS1 meter from the same dish and cable.

Have you considered that the levels are bound to be less as your using a smaller dish? Are the lower readings on horizontally polarised channels or Vertical ones?

If its horizontal ones the smaller dish will be the issue.

Nano

Thanks.

I believe Channel 5 HD is a horizontal, if it were just down to dish size I'd expect lower levels on all the satellites. 5E was about 67% and its now about 62% but Channel 5 HD is 77% and I'm pretty sure it was in the 90s. My other DM800 running the same image on an even smaller dish is showing Ch 5 HD as 82%, although that has an Inverto Ultra which always seem to show slightly higher levels. I'm not going to die in a ditch over it because as I say its unlikely to cause me any trouble on those particular satellites, I was just hoping the forum could offer some advice on things to check for. I'll probably just see how it goes until the spring as I've been freezing my nuts off on that roof this weekend. It feels great to have both systems back on multisat, 36v is still superior to Diseqc motors in my view.

 

[timo_w2s]

Nice setup. Could it be receiving too much signal from 28.2E and overloading?

 

[smiffie]

Nice setup. Could it be receiving too much signal from 28.2E and overloading?

I doubt it, I've never seen DM800's exibit that behaviour, I would imagine I would have seen it on the 105cm as 28E absolutely booms in on that rascal.

 

[Ghostleader]

Sounds lower than it should be mate, I have a multi LNB setup on a 80cm ISS perforated with a basic Fortec quad LNB sitting at a 15 degree offset & Channel five HD comes in at 80% signal quality on my Technomate 5402 HD & I'm in central Scotland!

Sent from my BlackBerry 8520 using Tapatalk

 

[remlap]

Nice to see the scaffolding, very sensible safe way of fitting a dish at roof level like yours.

Hope the dish performs as you want it to.

 

[smiffie]

Sounds lower than it should be mate, I have a multi LNB setup on a 80cm ISS perforated with a basic Fortec quad LNB sitting at a 15 degree offset & Channel five HD comes in at 80% signal quality on my Technomate 5402 HD & I'm in central Scotland!

Sent from my BlackBerry 8520 using Tapatalk

Does being in central Scotland make a difference as I think Channel 5 HD is on the Southern 2A beam? I actually reconnected the ISS 105cm on a patio stand last night with a Titanium 0.1 LNB, it was set with a slight skew and showed 97% on Ch5 HD. However the vertical transponders were extremly low until I experimented with the LNB skew and focus which brought in the vertical's but resulted in a drop with the horizontal's. It was just a quick exercise last night and I am a bit suspicious about the cable to that dish, but perhaps LNB skew/focus is an area I should look at with the motorised setup.

 

[smiffie]

Nice to see the scaffolding, very sensible safe way of fitting a dish at roof level like yours.

Hope the dish performs as you want it to.

It was a nice luxury to have this time around but not entirely ideal as the working height is only gutter level. You can buy the extra level to take you upto Apex height but I'm not sure whether I'd feel safe on such a small platform at that height. It is good to have a platform at that level to work from on the bracketery with tools and drills etc. then work off or between the scaffolding/ladder when the bracket is fixed and the ladder is tied on. I still needed work off the ladder for the final dish/motor lift and final adjustments.

 

[Lazarus]

Does being in central Scotland make a difference as I think Channel 5 HD is on the Southern 2A beam? I actually reconnected the ISS 105cm on a patio stand last night with a Titanium 0.1 LNB, it was set with a slight skew and showed 97% on Ch5 HD. However the vertical transponders were extremly low until I experimented with the LNB skew and focus which brought in the vertical's but resulted in a drop with the horizontal's. It was just a quick exercise last night and I am a bit suspicious about the cable to that dish, but perhaps LNB skew/focus is an area I should look at with the motorised setup.

smiffie, the skew issue is definitely a potential problem for some motorised systems owing to the pre-skew uniquely applied at the 28.2E Astra Satellites themselves.

For every other Satellite on the arc, setting the LNB to zero skew for the due South Satellite leads to automatic skew correction across the arc except for 28E.

In practice, for the vast majority of users, it makes no perceptible odds, but in certain circumstances it might be a problem.

Trouble is, if you tweak the LNB skew for best results on 28E, you'll throw off every other Satellite!

Can't win.

 

[smiffie]

smiffie, the skew issue is definitely a potential problem for some motorised systems owing to the pre-skew uniquely applied at the 28.2E Astra Satellites themselves.

For every other Satellite on the arc, setting the LNB to zero skew for the due South Satellite leads to automatic skew correction across the arc except for 28E.

In practice, for the vast majority of users, it makes no perceptible odds, but in certain circumstances it might be a problem.

Trouble is, if you tweak the LNB skew for best results on 28E, you'll throw off every other Satellite!

Can't win.

Thanks, I did understand those two issues that I've highlighted, although wasn't 16E also an oddball when it came to skew? Luckily my provider has moved from 16E to 23E so I don't really have to worry about that anymore. The fact that I've gained 10% by changing the LNB focal point maybe worth looking at again, I guess that adjustment will just be trial and error by gradually nudging the LNB within its mount and checking the levels.