GOES 16 GRB downlink vs GVAR

[GOES 12 GVAR user]

Planning on testing it on both the 2.4m and 3m. The 3m appears to have a tree (part of it) in the line of sight that might not be helping much with the current helical feed I have, but I did get a while back, good HRIT signal using a canantenna I built for it (when aimed to GOES16).

My dish setup(s) and tree configuration(s) in my area, petty much forces me to use the 3m for NOAAPORT and the 2.4M for GRB, but will nonetheless test on each and report.

You might be able to use the 8' dish on GRB but If all possible find a way to get a 10' for it as you'd put yourself very close to margin. Trees are easy to fix with a saw. HRIT can be acquired easily with both of those dishes as it's much stronger then the GRB signal.
One thing I want to point out that I was told so to pass it along.
The transmitters on the satellites when new put out slightly more power, then as they age the power can drop a little. That's why you want some margin on the signal so as time goes by that margin may keep you on the good side of things. Let alone inclement weather episodes that can reduce the link margin slightly. If you can get a couple of dB extra in margin the I'd go for it.
Even if you may have to put up another dish.

I use the SPF5189Z and the LNA4ALL. Although LNA4ALL gives a bit more performance, the SPF is a bit more sturdy in my opinion. On last note, I use a ZX60-P33ULN+ LNA at the feed and the aforementioned LNAs indoors for best performance.

They seem pretty similar by design. The minicircuits part you describe, I have something similar as well in my collection. Haven't messed with it much.

The Nooelec is closest to the dish feed. The other is at the receiver.

The "plan" would to be by stage:
Waveguide to probes short jumper to combiner (feed stage) short jumper, (SPF5189Z) or Ultra LNA or similar (1st stage) short jumper, bandpass filter (nooelect Sawbird+amp) or something similar (2nd Stage).
This point you have gotten every bit of gain out of the system that is possible so..
It will depend on the coax and receiver requirements, I can add the 60 dB amp (NWDZ Amp) (3rd Stage) in line to boost the incoming signal coming down the coax line or may be able to leave it out.
But I want the lowest noise in the first stage and the filter right behind that. These amps due to their boadband abilities can get overloaded by strong signals nearby not in our band. So get a filter in there to make that 2nd stage amp see only the signals of interest.
It helps that we use dishes and waveguide but with all the RF in the area it can still get in to a point.
I wouldn't be too worried about the 1st stage amp getting overloaded as the signals are very weak at this point. But after that it can become an issue.
My current test setup is just the waveguide to probes, short jumper to combiner, short jumper to 1st stage amp then 15' coax to receiver.

This LNA took about a week.

Thanks of the shipping info.
All those amps have a 1 dB noise figure or more. But for 2nd stage amps they will work fine.
If used for the 1st stage then you want to use the 1 dB NF one. Just a recommendation.

 

[GOES 12 GVAR user]

Ordered the filter and you do have to contact Nooelec by phone or email. The person you talk to on the phone may not know what it is so they forward the request to the sales dept. The sales dept. contacts you a short time later.
Nooelec does ask what it being used for and when I told them GOES they knew what it was.
Here is a response sweep of the filter by them.

Blue line would be the typical frequency response of the unit. Cost would be $34.95 plus shipping.

Also ordered the amps I wanted, so they show as of tonight they are being shipped from China.

 

[N6BY]

You might not need the extra amps. I was able to get a lock with the TBS card last night using only the Nooelec saw+lna. But the signal had too many sync errors to get any images.

 

[GOES 12 GVAR user]

I was able to get a lock with the TBS card last night using only the Nooelec saw+lna.

If all you're using is the filter + amp on your system then I'd say that's doing pretty good.
From what I know that Nooelec is a filter then amp.
If you are feeding the septum feed right into that filter then you are getting signal loss. This is critical.
Any type of inductors, filters, coaxial devices have insertion loss.
With my combiner I have a little loss but it's also made up with the combining of the signals.
That's why I have a first stage amp, you amp the raw signal from the feed then filter and amp it again after the filter loss.
I know that you may not have a preamp available now but I highly recommend that you amp that signal before it goes to the filter. It may make that difference you need.
Those filters have about a 3 dB insertion loss so you are losing 3 dB of your signal before it get to the amp if I'm understanding the setup correctly.
My system shall have amps 2 min.

 

[N6BY]

According to the guys in the Open Satellite Group, the Nooelec has a built-in pre-amp, then the filter, than a post-amp. But it would be good to verify this with Nooelec directly.

 

[KWX]

Ok, so after building/tuning the new can-antenna for 1690MHz with combiner, I got the following for GRB:

2.4m CN = 7.7dB to 8dB.
3m CN = 8.3dB to 8.5dB (if no trees then likely get more and may be a bit of feed leg tuning).

No errors on the above 6.5dB (threshold as we already know) with GRBStreamer. Pretty sure I can still get a bit more on the 2.4m with some additional tuning but won't complain with the performance I'm getting out of it.

Now, something interesting does happen with the TBS5925 and GRB. It won't lock to GRB unless the CN is between 6.0 and 6.5dB, but once locked then I can move dish back into peak position and data flow will continue as long as I don't attempt to lock again on the signal. Very likely is a driver type issue, but thankfully getting the DD PCIe card soon, so I should have better locks than the TBS5925 at higher CN.

So tempted to try go get both LHCP/RHCP by adding a simple SMA splitter to each of the N connectors and have a total of 4 jumper cables go to two combiners for each polarization... wonder if that would work lol.

 

[N6BY]

...5925 and GRB. It won't lock to GRB unless the CN is between 6.0 and 6.5dB, but once locked then I can move dish back into peak position and data flow will continue as long as I don't attempt to lock again on the signal. Very likely is a driver type issue, but thankfully getting the DD PCIe card soon, so I should have better locks than the TBS5925 at higher CN....

Congratulations on getting an error free lock! Have you tried streaming to GRBDump yet?

And I am seeing the same kind of odd behavior with the signal locking off peak. I can get a CN up to about 7.2 here in California. But I have to adjust the dish a bit to drop it down to the low 6's to get a lock. Can anyone explain this? The only thing I can think of is that TBS may be calculating the CN wrong? It will be interesting to see if we experience the same oddity with the DD cards (still waiting for mine).

 

[GOES 12 GVAR user]

According to the guys in the Open Satellite Group, the Nooelec has a built-in pre-amp, then the filter, than a post-amp.

You're right, amp, filter and amp. I never would have thought for the price that you would be getting that kind of microwave circuity, I am impressed!
I did ask Nooelec.

2.4m CN = 7.7dB to 8dB.
3m CN = 8.3dB to 8.5dB (if no trees then likely get more and may be a bit of feed leg tuning).

8 dB C/N is usable. A little low but usable. The trees are very likely affecting the 10' dish as you should be better than that.

Now, something interesting does happen with the TBS5925 and GRB. It won't lock to GRB unless the CN is between 6.0 and 6.5dB, but once locked then I can move dish back into peak position and data flow will continue as long as I don't attempt to lock again on the signal.

When you locked on the signal and peaked the dish did you see any frame drops in like every 200,000 or so?
That's an issue Brett has/had with his TBS card and I was wondering if you had the same issue. That is a weird issue on the lock though.

So tempted to try go get both LHCP/RHCP by adding a simple SMA splitter to each of the N connectors and have a total of 4 jumper cables go to two combiners for each polarization... wonder if that would work lol.

It may be possible but there are more calculations due to splitting the coax. I would just get one side up and going first then look at your different options.

 

[N6BY]

...
The simple way to combine the 2 probes is use a 90 degree signal combiner (part Minicircuits ZX10Q-2-25) use a terminator cap and you're done....

I just looked at their website and they have a ZX10Q-2-25 and a ZX10Q-2-25+. Do you know what the difference is? Which one did you and KWX get? Thanks.

 

[GOES 12 GVAR user]

Do you know what the difference is? Which one did you and KWX get? Thanks.

The "+" means RoHS compliant. I got the ZX10Q-2-25 as pictured.
Full part # ZX10Q-2-25-S
The "S" is for SMA connectors I believe.

 

[KWX]

Congratulations on getting an error free lock! Have you tried streaming to GRBDump yet?

And I am seeing the same kind of odd behavior with the signal locking off peak. I can get a CN up to about 7.2 here in California. But I have to adjust the dish a bit to drop it down to the low 6's to get a lock. Can anyone explain this? The only thing I can think of is that TBS may be calculating the CN wrong? It will be interesting to see if we experience the same oddity with the DD cards (still waiting for mine).

Thanks, that's the next phase. Looking to have later today my processing GRB "server" finalized to test GRBDump and a bit after CSPP-GEO.

 

[KWX]

...

8 dB C/N is usable. A little low but usable. The trees are very likely affecting the 10' dish as you should be better than that.

Couldn't agree more.

When you locked on the signal and peaked the dish did you see any frame drops in like every 200,000 or so?
That's an issue Brett has/had with his TBS card and I was wondering if you had the same issue. That is a weird issue on the lock though.

No frame drops. I would only get frame drops if my CN dropped below 6.5 at a slow rate and increasingly be in the tens as I moved further away from the threshold, but not in the magnitude of 200K.
In regards the lock, I believe it could be due to the possible interference from terrestrial signals and it could be having a hard time differentiating between them and GRB. I say this because, I used a 1690MHZ minicircuit filter and my lock-ability at a bit higher CN improved, but still have to be below the 6.7CN range to lock with the TBS.

It may be possible but there are more calculations due to splitting the coax. I would just get one side up and going first then look at your different options.

Yeap

 

[KWX]

I just looked at their website and they have a ZX10Q-2-25 and a ZX10Q-2-25+. Do you know what the difference is? Which one did you and KWX get? Thanks.

I got the ZX10Q-2-25.

 

[KWX]

Congratulations on getting an error free lock! Have you tried streaming to GRBDump yet?.

Here's a sample from Mesoscale Sector 1 - Band 14 (using GRBDump):

 

[GOES 12 GVAR user]

No frame drops. I would only get frame drops if my CN dropped below 6.5 at a slow rate and increasingly be in the tens as I moved further away from the threshold, but not in the magnitude of 200K.

Back earlier in the discussion Brett was having that issue when the was testing his streamer software so I was seeing if anyone else has had such issues. I have ordered my TBS5927, I'll see what it does when it gets here.
And congrads on the setup.
KNX, I did notice something on your image you might find interesting, the colors are inverted. I reversed the colors and...

Same thing Brett in post 159 on page 8 with some not all images you loaded..

For some reason GRBDump is inverting the grayscale, meaning the colds are black and the warms are white. It's not doing this will all though.

 

[KWX]

Back earlier in the discussion Brett was having that issue when the was testing his streamer software so I was seeing if anyone else has had such issues. I have ordered my TBS5927, I'll see what it does when it gets here.
And congrads on the setup.
KNX, I did notice something on your image you might find interesting, the colors are inverted. I reversed the colors and...
...

Same thing Brett in post 159 on page 8 with some not all images you loaded..
...
...

For some reason GRBDump is inverting the grayscale, meaning the colds are black and the warms are white. It's not doing this will all though.

Nice, will be interesting to see if you get the same locking issue that we've seen so far with the TBS5927.

In regards the colors, I was wondering why the colors were off so you just answered it. Interesting enough HRIT images if I'm not mistaking also come inverted.

 

[KWX]

Now in regards GRBDump. It is running slow, even on an i7 "server" only processing the GRB data. So because of this, I'm noticing a lot of missing tiles on most of the images even though there are no errors in the stream. CPU/Memory usage are low and no I/O waits, so no bottlenecks on the system that I can see, so it has to be the software.

Interesting enough even after stopping GRBStreamer, it took GRBDump between 15 to 20 min to process the rest of the data in the queue.

 

[N6BY]

I got the ZX10Q-2-25.

Thanks for letting me know, I'll order the same (plus a terminator). I assume these just contain passive coils and no input power required, correct?

Congratulations of getting your first GRB images.

My GRB signal error rate here in California is way too high right now for image generation. It worked once in the middle of the night, but most of the time its just frustrating.

I'm going back to the Quaker cantenna as soon as my ZX10Q-2-25 arrives. Just have to add another probe at 90 degrees. The Quaker cantenna is about 98% lighter than the septum feed, which is so heavy it sags on the dish struts.

Looking at the specs of the ZX10Q-2-25, the cross polarity isolation is 20 to 25 dB -- very good!

 

[GOES 12 GVAR user]

I assume these just contain passive coils and no input power required, correct?

No power required for the combiner.
Downloaded your streamer Brett, I'll be trying it here sometime soon.
Been too cold outside lately to do much.

 

[GOES 12 GVAR user]

I did the last image that N6BY loaded on page 8 and it was also inverted, So it looks as if GRBDump is doing it to all them that I can tell from what you guys have uploaded. But I suspect it don't do it to the visible images.