Random results when blind scanning 127W

N6BY

Geek
Original poster
Lifetime Supporter
Mar 1, 2006
3,174
3,058
Roseville, CA 121W
This is strange. I was able to watch NASA TV a few days ago. But for the last couple of days I cannot receive it.

An EBS Pro scan shows that 4008.6 V on 127W is coming in at 16.9 dB which is excellent. Yet my Edision OS Mio does not show it when I do a transponder scan. A regular channel scan doesn't get NASA TV either.

Below is an EBS Pro screen shot showing that 4008.6 V is being received at 16.9 dB. But when I do a service scan on the same transponder it displayed "ERR" (2nd screen shot below).

What could be going wrong?

127HScan.jpg



4009VErr.jpg
 
Just checked here, not receiving anything on 127W at the moment. Was watching NASA for a bit late this afternoon before supper and it was working then. Maybe I have some snow that made it into the LNB feedhorn, but maybe something else on the satellite side...

Just checked, signal is there just not strong enough for a lock. It's -25 here so not going out to clean out the LNB now, would end up breaking it.

1670301474698.png
 
Coming in fine here now at 10am CST. About 11dB S/N. Not a lot of headroom though for an S2 signal. Used to get this at 13-14dB with the 8 foot offset.
Also not picking up the 4020H mux. Too cold out to bring out the SA to the dish to measure. Need one of the old tube-type to take out there, can double as a hand-warmer! :) Might just have one kicking around, would likely be a career move to get it working again though.
 
  • Like
Reactions: N6BY
127W. All working here:
4009/V/15000 - NASA Mux
4140/H/30000 - Cowboy, Cowgirl*, NewsMax, You Too America
4020/H/30000 - JBS. Reelz
3980/H/30000 - Weather

*I removed Cowgirl, so I assume it is still working.
 
  • Haha
Reactions: N6BY
I have narrowed down the problem. The signal here in California is very strong, now 17.0 dB. But when I blind scan the satellite NASA is on (127W) I get anywhere from 11 to 15 transponders on my OS Mio+ 4K. Sometimes the NASA transponder is included (about 1/3 of the time), and the rest of the time it isn't.

But once the NASA transponder blind scans in OK, as long as I don't do another blind scan I continue to get NASA

Also, I have strong 5G interference here. So my best guess is that 5G interferes with blind scanning.

Also, NASA 101 shows a black screen and then I get a message "Service invalid! [Timeout reading PMT]. NASA 103 and "EDM UHD Encoder" work OK.

Is anyone else seeing an error message on NASA 101?
 
N6BY what size dish are you using? 17dB is a lot of signal compared to my system!
I could swing the 10 footer over there but -30's this am, not conducive to moving the dish very much if at all. The 8' offset is dedicated to 127W. Used to pick up all the TPs on that satellite. Maybe something in the RF chain is breaking down a bit here. No 5G interference around this area.
 
N6BY what size dish are you using? 17dB is a lot of signal compared to my system!
I could swing the 10 footer over there but -30's this am, not conducive to moving the dish very much if at all. The 8' offset is dedicated to 127W. Used to pick up all the TPs on that satellite. Maybe something in the RF chain is breaking down a bit here. No 5G interference around this area.
It's a Unimesh 10' dish. I'm in California at about 121W longitude so 127W is not far from due south for me. I am using a Titanium C138 LNBF because there is strong 5G here.

But even with 17.0 dB SNR as reported by the OS Mio, blind scan often doesn't 'see' the NASA channels. And I just tried a blind scan of 127W. It picked up only 10 of the 15 transponders and I am now without any of the NASA channels.

So I think either the 5G is messing up my blind scan or I need to try another receiver.

And it's a sunny day here today without any wind or clouds, so weather is not a factor.
 
Just got home, and coming in great here. Snowy and windy.

I believe NASA is the only thing on the other polarity from all the other channels. Maybe there’s an issue there? Either the receiver not sending a reliable polarity change, or the LNBF not doing it?

Is your dish movable? Can you check other satellites to see if channels on the other polarity act up too?
 
...

I believe NASA is the only thing on the other polarity from all the other channels. Maybe there’s an issue there? Either the receiver not sending a reliable polarity change, or the LNBF not doing it?

Is your dish movable? Can you check other satellites to see if channels on the other polarity act up too?
Both of my dishes are concreted in the ground. Last night I moved my Titanium C138 LNBF to my Birdview dish on the other (south) side of the house and reception is worse. The Unimesh is on the north side.

With the Birdview I can get NASA 101 and other channels but they are pixelated. With the Unimesh I got a black screen with NASA 101, but the other 2 NASA channels come in OK.

I even tried another receiver with similar results. The only thing in common is the Titanium C138 LNBF and both dishes are in an area with strong 5G interference.
 
Both of my dishes are concreted in the ground. Last night I moved my Titanium C138 LNBF to my Birdview dish on the other (south) side of the house and reception is worse. The Unimesh is on the north side.

With the Birdview I can get NASA 101 and other channels but they are pixelated. With the Unimesh I got a black screen with NASA 101, but the other 2 NASA channels come in OK.

I even tried another receiver with similar results. The only thing in common is the Titanium C138 LNBF and both dishes are in an area with strong 5G interference.
After moving my C138 back to the Unimesh and several blind scans a few days ago, I am now able to get NASA 101 again.

Every blind scan seems to bring in a random number of transponders on 127W. (I can't understand why as there is no wind and its a clear day). So I'll just leave the C138 on my 10' Unimesh which is bigger than the Birdview and I won't be doing and more C Band blind scans.
 
Maybe the STB firmware needs to be reset or try a different firmware / slot?
Its worth a try. I will definitely use a different slot so I don't lose NASA. I also found another old receiver to try. Will let you guys know what happens when scanning in 127W.
N6BY Just saw this, not sure you'd want to spend this sort of money, but it's an option in extreme cases. Maybe you can find it a bit cheaper elsewhere, I haven't looked: Dual C-Band (5G) Orthogonal Feedhorn with waveguide post filter and mini LNB | Tek2000.com
That would definitely be beyond my budget right now, especially since my wife retired early for about 1/4 her former salary and my software business is severely struggling.
 
N6BY Just saw this, not sure you'd want to spend this sort of money, but it's an option in extreme cases. Maybe you can find it a bit cheaper elsewhere, I haven't looked: Dual C-Band (5G) Orthogonal Feedhorn with waveguide post filter and mini LNB | Tek2000.com
Not bashing the seller, but overpriced for an Ali Express product. Poor quality lnb's. (I bought 4 similar from Ali... only 1 still working after 4 months)

You can buy direct from Ali Express (Including Shipping):
Dual feed horn - $44.46.
2 wave guides - $430.90
Total - $475.36
Maybe a bit cheaper if you dig around Ali further.
Then purchase 2 good lnb's elsewhere! Norsat or similar

This will only work until 5G expands into the 3800 - 4000Mhz range. At which point you MAY need to buy new wave guides and lnb's!

Not a cheap solution any way you figure it.

* Fortunately I don't have 5G interference to date. Running 2 dual feed horns with 4 various lnb's. No wave guides or 5G blocking lnb's needed.

Edit, Forget to add: If buying wave guides or lnb's, be sure the freqs are 3800 - 4200Mhz. Much of the '5G interference' stuff on Ali is for a 3700Mhz cutoff. These will not do what we need here in the USA.
 
  • Like
Reactions: N6BY
...
Edit, Forget to add: If buying wave guides or lnb's, be sure the freqs are 3800 - 4200Mhz. Much of the '5G interference' stuff on Ali is for a 3700Mhz cutoff. These will not do what we need here in the USA.
I noticed that on Ali Express too. You can get a 3700-4200 5G filter LNBF for approx. $30 to $50 total including shipping. I wonder what it would take to modify one of those for 3800 -4200, or even 4000-4200? Maybe changing one of the surface mount inductor or capacitor values? I don't design cutoff filters so maybe someone can enlighten me?

... You're lucky you don't live in a 5G infested area like me. 5G Band "N77" is the culprit and they are using it in my area for 5G home internet. Its too bad because there are so many other bands they could have used. And most of these homes around me have fiber optic internet because they were built after 2005, so it's not like they really need 5G. But 5G internet is advertised for as little as $25 a month, so there is a strong incentive for my neighbors to give it a try.

And every neighbor who gets 5G internet will become a new source of interference.
 
Last edited: