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Satellite Television - BBC World

This page documents my venture into receiving BBC World on Intelsat 5 (C-band) on my 90 cm Satellite dish in Wellington, New Zealand.  I had been using a 90 cm dish for Freeview reception on Optus D1 and also Optus D2 (moving the dish), and after reading that it was possible to get C-band on the dish I decided to get set up with C-band and D1.  My installation:

The dish, Ku-band LNB and satellite receiver were purchased from Freeviewshop a few years ago.  They aren't the latest and greatest, and are not optimal for C-band reception.  However, I recommend you check out JX-Satellite for your satellite equipment - their online shopping cart isn't as easy to use, but their after-sales service is vastly superior.

Satellite dish

Satellite Dish

If you previously had the dish tuned to D1 or D2, it needs to be moved right and up slightly (when standing behind the dish) for IS5.  There are some good articles on the DishTV support page to help you align the dish.  I don't find the satellite finder meters much help.  It is easier to use the signal meter on the satellite receiver for tuning - provided you can see the TV screen when moving the dish (which I can).  On the Strong you select manual scan for an appropriate TP, and move the dish until the red signal level and signal quality meters turn green.  Tuning in C-band is much harder.  I was only able to get a signal with the conical horn attached to the LNB.  This means that the LNB position, skew and horn position much be approximately right before you position the dish.  Once the dish is positioned correctly for C-band the D1 LNB can be mounted and adjusted.  This bracket was set up for me by JX-Satellite, and fine adjustment for maximum signal is relatively easy.

Note that the wall mounting bracket (even the rugged one with stay rods, not the flimsy one that is supplied with the dish) doesn't  permit you to mount the dish against a vertical wall.  It is fine if the dish protrudes above the roof line, or with a 65 cm - 75 cm dish.  However, with a 90 cm dish the dish cannot be positioned for D1/D2 without it hitting the wall.  As you tip the dish back to align to the satellite, the wall is in the way.  I got round this by firmly mounting the wall mount 10 cm away from the wall (you can vaguely see the robust wooden block in the photo above - the wooden block is one used as a house pile).  I have no idea why a wall mount is sold for a 90 cm dish that doesn't actually allow you to mount the dish against the wall!

LNB's

The C-band LNB should be in 11 o'clock (or 5 o'clock) skew position. My LNB is positioned with the black pastic bracket around the "34" marking on the LNB, about 64 cm from the front of the dish.  The horn I mounted up close to the plastic bracket.  In practice, the positioning had quite a broad peak - a cm or so in or out didn't make a great deal of difference (Ku-and tuning was a lot sharper).  In my case I found that the signal was slightly better in the 5 o'clock position than the 11 o'clock position, though there should be no reason that this is so.

The Ku-band LNB is mounted with skew in the 8 o'clock position.  See pictures below.

LNB side view

LNB reverse view

Satellite Receiver

For a dual LNB configuration like this you would normally use a DiSEqC switch, and use the dish settings in the satellite receiver to ensure that the correct LNB is used for the correct frequency bands (this didnt' work for me - see below).  For these LNBs the key settings in the receiver are:

For C-band, manually set the TP for 4160 Horizontal and do a manual scan.  You will pick up BBC World and the Australian Network. 

Issues

My set up is not ideal, and I found the C-band signal strength to be marginal.  I get a fairly solid 54% signal quality.  The satellite receiver cuts out at around 47% - 48%, with pixelation below about 50% (note that this is signal quality, not signal level which is always around 90% and fairly meaningless).  This 54% level is okay, but when I connected up a DiSEqC switch, the 3 dB insertion loss of the switch was too much.  It only worked about 10% of the time, which was unusuable.  So I have two feeds coming in (one from each LNB) and I have to manually swap leads when I change channels!  Not ideal, but I simply don't have enough C-band signal.  A few more dB is all I need, and I believe a more modern setup would achieve this using:

Several online stores offer packages, including JX-satellite and Freeviewshop, promising D1 and/or D2 and IS5 on one 90 cm dish.   Interestingtly, when I inquired about getting this set up for me with my existing equipment, there wasn't a satellite installer in the Wellington region willing to do this.  In fact, there wasn't anyone interested in setting up IS5 for me in the Wellington area.  It is marginal on a 90 cm dish.  DishTV (the satellite dish manufacturers) recommend a 1.2 metre or larger dish for C-band.  A larger dish would deliver better signal quality, but larger dishes also require considerably more space for installation, and the larger dishes are easier to mount on the ground than a roof-top.  The other consideration for large dishes in the Wellington area is wind!  My 90 cm dish is mounted on the side of the house sheltered from the southerly, but still requires a firm mounting with stay rods to prevent the dish moving in the wind.  There is no difficulty getting both D1 and IS5 on one dish, but research on the internet suggests that adding D2 can be fiddly to set up.  I haven't attempted this.

The C-band LNB comes with a simple plastic end ring, which does not keep out the rain. Some sort of plastic cover is required over the conical horn to keep the rain out.  The angle is such that rain will seep in and collect at the back of the Pacific LNB, and that kills reception real quick!  I haven't found yet a 15 cm plastic cover that fits the outside of the conical horn.  A simple plastic cover can be taped in place, and I recommend something to keep the rain out (but also let the cavity breath - otherwise condensation may build up inside).  Other places recommend drilling a hole in the LNB to let the water drain out, but I was reluctant to do that.  There doesn't appear to be a commercial plastic cover available, but check out yoghurt or other circular plastic containers.

Performance

BBC and the Australia Network on C-band deliver a 54% signal quality.  Despite being told that there is no rain fade on C-band, the signal quality does drop a couple of percentage during rainy weather.  However, reception is rock steady and excellent quality.  BBC World news free to air.

BBC World

D1 Freeview signals come in at around 92% signal quality, and the Australian SBS channels at around 75%.  I'm very happy with this.

Recommendations for C-band

 

© In the Light, 18 March, 2011 , Disclaimer, Son of Suckerfish drop-downs from HTML dog