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DIRECTV Satellite Discussion SKYM-1 (Ku-79W) @79W

25K views 99 replies 15 participants last post by  HoTat2 
#1 ·
#79 ·
doctor j said:
Application for an RB-79 payload to be added to KU-79 for Sky Mexico

Doctor j

https://apps.fcc.gov/edocs_public/attachmatch/DA-16-155A1.pdf
Good catch, though to note the uplink frequency band listed for the Reverse band payload RB-79W (S2861) is apparently mislabeled as "24.750-25.50 GHz."

Whereas it should be 24.750-25.250 GHz for non-US operation which is 100 MHz less at 24.750-25.150 GHz.

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#80 ·
I was able to provide Gary Toma with the Beam footprint maps from KU-79 and RB-79, taken from the April 2015 FCC filings. The RB-79 beams (TBL and TBR) match what was in the library previously, but the Ku beams TKH and TKV are significantly different. The CONUS Beams, which were not in the last filings, have been removed. The beam footprint files for Google Earth are here: http://www.dbstalk.com/topic/184044-interactive-beam-footprint-library/page-6#entry3355060

Note that the footprint patterns are identical for TKH and TKV, TBL and TBR are also identical to each other, but they are documented as separate beams in the FCC filings.
 
#83 ·
Wicked said:
Has anyone scanned this sat from the US? Is reception possible with the same type of antenna they are doing installations with? if in the footprint?
The satellite is intended for Mexico, and it only hits there. The signal bleeds into the extreme southern edge of the US as you can see here:

http://www.dbstalk.com/topic/184044-interactive-beam-footprint-library/page-6#entry3355060

Since it is linearly polarized, unlike the circular polarization Directv & Dish use in the US, the dishes used here for those services would not work even if you were near enough to the border.
 
#84 ·
slice1900 said:
Since it is linearly polarized, unlike the circular polarization Directv & Dish use in the US, the dishes used here for those services would not work even if you were near enough to the border.
It is possible to receive a linear signal on a circular LNB, but one will get better results with the right LNB for the signal being received.
 
#85 ·
[mod hat on]
Note that it is the policy of these forums to not discuss actions that would violate the terms of service of the service providers. That includes receiving programming outside of the designated market area it is intended for. Please drop the discussion of reception of the Latin American service within the US.
Thanks
[mod hat off]
 
#86 ·
Muchas Gracias to Eduardo, our Latin American team member, on assignment in Mexico. I have added the Sky Mexico Band Plan to the US and Latin American ones HERE.
Hey great news Tom ...

To now have a SKY Mex. correspondent down there for that service.

Think Eduardo might be able to shed some light on the 76W/79W SKY Mex. LNB as to its specific voltage/tone switching? And how connecting both LNB ports to the 13 and 18v voltage + tone generating ports on a SWiM-8 multiswitch in the pictures we have actually works?

Also, are XNPDRs 25 and 26 for IS-21 phantom transponders in the data stream or something?

As the Schedule S and accompanying Engineering Statement for IS-21 (call sign S2863) list no such ones for Ku service to Mex. Only 1 thru 24 between 11.720-12.180 GHz center freqs. on the downlink.

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#87 ·
Eduardo has had limited time to gather data for us. He is travelling a great deal. What we did get was the result of him being home recovering from an illness for a few days, when we could work with him. He does not have access to the location of the SWM switch, so cannot shed light on that configuration. I put what we had into the Band Plan without a great deal of analysis, because I was busy after that. Eduardo has subscribed to what Sky-Mexico called "HD Total" last year, which they heavily promoted to eliminate the need for a separate dish for IS-21. This year they have rebranded their service as "skyHD" for all of their packages. When Sky-M2 begins service, I doubt it will be used in the same installation as IS-21, so the switch just has to handle two LNB's on Ku and two on RDBS in the future. It looks like they are retiring IS-21 from Mexican service as fast as possible. You are correct about TPNs 25 and 26. The FCC filing does not show any transponder on those frequencies, they looked suspicious but I didn't research it. I should probably remove them. Eduardo has no way of verifying that, since he receives no service and has no SS display from IS-21.
 
#88 ·
Oh ok ...

Was hoping Eduardo might just know about the LNB's voltage/tone switching selection without having to actually go look at the SWiM multiswitch.

If one of the ports on the LNB were hooked to one of the non tone generating ports of the multiswitch (13v/99W/101W or 18v/99W/101W) it would make sense for a "twin stacked LNB" as it allegedly is. But not with both connected to the voltage + tone generating ports 18v/103W/110W/119W and 13v/103W/119W of the switch.

And yes, the future SKY Mex. 2 should be the same as "KU-76W," which as the title indicates is destined for 76W. So the LNB should be capable of switching between 76 and 79W on either port and produce a stacked frequency output for either satellite position. Odd XNPDRs between 950-1450 MHz and even ones between 1650-2150 MHz.

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#91 ·
I don't believe that is an incorrect hookup. I just think you are expecting that LNB to be more than it is. Eduardo has indicated that SkyM-2 will require a newer LNB. I believe that the 22kHz tone is turned on for all channels from SkyM-1, and 13v/18v selects polarity. The other two ports on the SWM-8 will be used for SkyM-2. They may have been used for IS-21 in the past, if a second dish was installed.
 
#92 ·
It's just after a lot of study it seems as the name of the LNB indicates, "(MDUAL) Monoblock Dual Stacked LNBF" ...

"Monoblock" = Meaning a multisat LNB comprising multiple fixed space LNBFs on the same assembly.

"Dual" = For two LNBFs, one for receiving from 76W and the other for 79W.

"Stacked" = Each LNBF generates a stacked transponder output (odd #s 950-1450 MHz, even #s 1650-2150 MHz) from the satellite at its respective slot as in the illustration...

Tapatalk Cloud - Downlaoad File stacked-lnb.gif

Note: The SKY Mex. LNB would use the 10.75 and 13.85 MHz LO pair.

The problem is the usual design of a twin stacked LNB does not use 18v/13v voltage selection on its ports, but as with any frequency stacker typically operates with any fixed voltage in the range of about 9-20v on one or both ports. And the 22 KHz tone is used to switch LNBFs so either port can receive the alternate satellite position.

And this is where the one closeup photo we have makes no sense, as one of the two coax lines from the LNB should be connected to one of the no tone ports of the multiswitch so one LNB port feeds the switch the stacked output from 79W and the other port would be the stacked output from 76W (when it exists of course).

This makes me speculate that the hookup in the photo is incorrect for receiving future signals from 76W. As both LNBs are receiving the same signals only from 79W in the photo's hookup.

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#93 ·
Or IOW ...

The SKY Mex. LNB port A with 18v or 13v (voltage level should be irrelevant to power the LNB and its internal stacker electronics) and no tone selects the 76W satellite position of the future SKY Mex. 2 satellite (or KU-76W).

And LNB port B with 18v or 13v (again specific voltage level is irrelevant for the same reasons above) plus the 22 KHz tone selects the current 79W satellite SKY Mex. 1

Reverse Band capability for when the current RB-79W and future RB-76W payloads go active will require an altogether new LNB I would think ...

And I wasn't aware there was ever a combined 58W/76W/79W dish hookup option through the same SWiM multiswitch. I thought 58W is being used nowadays as a totally separate SD only service for Mexico and other south of the border customers who either don't want to pay for HD or awaiting availability to convert to the new skyHD service at 76W/79W?

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#94 ·
I don't believe the LNB you reference is being used in the installations we know about. From what I can determine, the current installations use the same LOF for both polarities, and the tone is on for all of the current channels for 79W. The band stacking LNB may be to enable the RB channels.
 
#96 ·
You're most right ...

Sorry to go on so beyond questions specifically about the band plan.

Mods please move my last series of posts here mainly dealing with the SKY Mex. LNB question to the SKY Mex-1 or 2 thread.

Thanks. ...

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#97 ·
Hello good afternoon friends, Sky Mexico is looking to unify its prepaid and postpaid services on the skym1 satellite. That is why it launched its service VTV HD which like the postpaid will have an elliptical antenna, but what caught my attention is the LNB a very different way to the one used in the prepaid service. I will try to investigate what differences may have beyond design, now I leave photos.


Enviado desde mi Moto G Play mediante Tapatalk
 
#98 ·
Well ....

Since there looks to be only a single coax output and the SKY Mexico service will eventually be from two sat. positions. I would guess the LNB is a SWiM integrated type.

But what's sort of puzzling is that the very elongated vertical shape of the feedhorn is typical for a single satellite position type. Whereas the SKY Mex. service will eventually come from 76 and 79W (once SKYMex-2 is launched).

Therefore I would have expected a more "squarish" shape to the feedhorn as with the previous LNBs.

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#99 ·
I'm more surprised about the shape of the dish. Why such a wide dish for only two positions? Maybe they decided to re-use the Slimline shape even though it was unnecessary because of economies of scale??
 
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