Satellite trucks!

[ppppenguin]

This is quite a parade of satellite trucks in NYC today for Trump's trial. Judging by the dish sizes, some are still using Ku band (12-18GHz), whereas these days Ka band (26.5-40GHz) is dominant, mainly because it's cheaper to operate.

You can see the BECG's own satellite truck (Ku band) at our open days on 25/26 May. We aren't allowed to transmit but we may be able to downlink some pictures.

[Mike Watterson]

Are you going by dish size? That might just relate to which satellite is being uplinked or TX (ODU) power, rather than Ka or Ku. It's safe to assume none are C band! :D

Any transatlantic links are probably by Earth station, thus an extra hop to get live TV here. I could get some USA feeds from mid Atlantic sats when I had a motorised dish.

More capacity on Ka band. The Geosynchronous Ka band sats use up to 70 spot beams, each a tiny fraction of the economic Ku size spot. So each  frequency might be reused twenty times by one satellite. Also the higher frequency bands are bigger.

A dish might be Ka or Ku or C or all three. I've had a Ku ODU here for two-way, and eye balled Ka and Ku two way links. They look the same. There is even a special reflector that lets through Ka and reflects Ku (or is it vice versa?) so two LNBFs or ODUs can be mounted on one arm for Ka & Ku at the same satellite.

I've 4 x Quattro Ku LNBFs and one Ka (2 port as it's just H & V, not dual band) LNBF into a multiswitch. Though Wikipedia claims Ka is 26 GHz to 40 GHz, most Satellite Ka in last 15 years is about 19 GHz to 21 Ghz for downlink and maybe 28 to 31 GHz for uplink. The Ku is what Sky & Freesat use and is 10.7GHz to 12.1 GHz approximately. It's a 1.1 m or 1.2 m dish with a curved mount on the arm for LNBs from 9E to 28.2E. You need a bigger dish as off axis gain is poorer. So dish points at 16E to give best gain for 13E and 19E LNBFs either side of the arm.

On Sky 28.2E the Irish TV channels use Sky encryption,  on Ku band. But on 9E, the Irish TV channels (except Virgin/UPC) are FTA, on Ka band because the frequency reuse and narrow spots make reception in most of GB impracticable or impossible.

     
₣rom 2010. Same colour spot is the same frequencies. There are several Ka birds for ConUS.

This is a Ka band ODU. The slim bit at top back is an LNB for receive. The heatsink bit underneath is a 5W Ka band transmitter.
   

Transmit and receive use different bands (Uplink / downlink) and polarisation.

Here is a diagram of how the frequency reuse causes zones where the spot can't be received no matter how big the dish is:
   

Ka-Sat that I'm receiving Irish TV & Radio on right now, proposed bands in 2010.
   

The ODUs and LNBFs look the same for Ku and Ka.

The spot beams are lower power than Sky/Freesat, so while 45cm dish works in London for 28.2E Ku (Sky/Freesat and it's 65 cm here as we are closer to the edge of the beam), 90cm is recommended here for 9E Ka, even though the gain vs frequency means for C band you need twice as big a dish and Ka band half as big a dish (diameter), but only if the signal was the same!
Hence a minimum C band dish is about 2m and since it's lower frequency larger holes than Sky dish will work. A 3m mesh dish is good.

A solid 90cm Ku band dish will work for Ka, but a Sky type dish, even if 90cm is too poor due to the perforations. It hardly affects wind load. Cheaper to press to shape and cheaper to ship, but more prone to rust. A 60cm Ku band dish will work fine on Ka band till it rains!

I had to give back the 2 way stuff in 2008.

I modified a Cassegrain enclosed sat dish for terrestrial microwave use and it was used for nearly 15 years for my internet to make a 9km max system work at 13 km.

When I worked at the BBC the OB had to have line of sight to a TV mast. Terrestrial microwave links used and the dish on top of the OB truck pointed at the TV mast.

[Mike Watterson]

Even if you have an uplink licence, you'd lose it by pointing at the wrong satellite. But the modern stuff uses GPS to decide where to point the dish. All automatic.

[Mike Watterson]

And your modem or setbox doesn't care about C, Ku or Ka, because the IF frequencies and control signals to LNBF or ODU are the same. My satboxes have no Ka option, so either I Blind Scan or calculate a fake Ku frequency from the Ka one to enter a transponder.

[Mike Watterson]

My dish with 4 x Ku and 1 x Ka LNBfs. The 28.2E is on the west (left of image), and the 9E is on the east (right of image), due to reflection of dish.
   
Ecowitt weather station is actually on same pole but higher that it seems. The tall pole with a cable is a washing line next door behind us and it's higher ground.

That's a 6.2m CB aerial (Albrecht) behind for workshop CB. The proper radios are in the house (3.5m vertical on chimney and 22m long wire to front gate flagpole (not needing planning permission!).

Closer view
   
Sorry very silhouetted. But the Ka band Dual LNBF (not a Twin) is the most normal looking.
Some of the Quattros are Alps with a dielectric focus, others are Triax with the common Fresnel ring/small horn final focus. The Ku LNBFs and dish are nearly 17 years old. I had to replace the multiswitch a few years ago due to a leak in the shed roof.

Just pics on an old phone. A quattro (or dual) rather than quad or (twin) has each polarisation and band on a separate connection, rather multiple identical signals so the IF signals can be split to to feed up to 1024 outlets via cascaded multi-switches. I designed a system that could feed two satellite connections, TV & Radio, Cable TV and two DOCSIS broadband services on one pair of coax to up to 512 outlets.
I only have 12 outlets at home, but each cable in the house has three way diplexer to split satellite, radio and TV. The TV aerial, technomate HDMI to DVB-T modulator and radio aerial are combined in the attic and feed on a coax out in the shed where the multi-switch is. The system can also use the fibre LNBFs or single coax multi-satellite LNBFs (favoured by Sky now), via add-ons. I've no Sky box or freesat branded box now, but because the default is to feed LNBF #1 if no commands are sent, the #1 is 28.2E, so a Sky box or Freesat box would work. The #2 is 19.2E, #3 is 13E, #4 has three cables from 23.5E and one cable from 9E (Ka), so I don't get all the channels on 23.5E, but get the Irish channels instead on that LNBF setting on the setboxes or TV.

I could also feed in an analogue modulator or two as all the "digital TVs" also have analogue tuners. I gave away the Humax Freesat recorder as it was a pain on other than Freesat and would only record freesat. My cheap €45 to €90 (combo DTT + sat) boxes all record on USB sticks or USB HDD and the resulting files play on any laptop/PC/Tablet via VLC. They work fine with Freesat & Sky FTA channels, though only now/next EPG. Full epg on German stations. Some even take a Conax PayTV card (legally possible to have EU subs) and have built in WiFi (not used) for streaming. A few have Ethernet. All have SCART and some have audio + composite on a 4 pole 3.5mm jack, and that feeds the cheap MP3/Phone FM transmitters for car radio to give a few extra FM radio stations in the house. Power consumption less than 12W each.

[Mike Watterson]

A better contrast photo at noon.