GOES 16 GRB downlink vs GVAR

[N6BY]

This is a bit off topic, but there is a new XRIT decoder for Windows at: XRITDecoder

Also the same site has all the back issues of Geo Web Quarterly: Quarterly Back Issue Archive
They talk about receiving weather satellites. Its also the magazine that reviewed the TBS5927 that Timothy linked a few posts above.

 

[KWX]

Do you think its locking the ATSC signal using the Hauppauge card or is GRBStreamer getting its devices confused?

Also was wondering if you are using a septum feed on your dish or something else.

Good question, I'm actually more inclined on the latter as it could had gotten the devices switched as it was enumerating them or afterwards.

In regards the feed, I'm actually testing different options before settling with one, but so far the 3 turn helical has been the one with the most gains.

I'm definitely trying GOES12's coffee can feed and see how it goes this upcoming week once built.

 

[KWX]

...

I would recommend that you go to the 10' dish for GRB as it's been the best choice for use. Since NOAAPORT has moved to Galaxy it's about 2 dB stronger.
I (think) NOAAPORT will work on the smaller dish there on the ECOUNUS.

Quite true, I did gained between 3 to 3.5dB by going to Galaxy (very happy when I saw that), so changes are high as you have recommended on going with the 10'.

 

[GOES 12 GVAR user]

Also, as you probably already know, the wavelength in the wave guide is longer than in free space.

Brett, if I think what your telling me is the wavelength in coax is longer then free space hold on a moment..
My ARRL handbook talks about making coax transformers and when the formula is given it's like..
468 OR 234 divide by Freq. X vel. factor.

So in the case of RG6 this would = 1.32" for a quarter wavelength.
Coax is not considered a waveguide in those terms.
I remember this clearly as I cussed a 2M beam balun when I missed calculating the vel. factor. Could not get that thing to match for nothing.

For any newbes here I will explain.

To find a wavelength in free space the formula is

468 or 234 divide by freq in MHz
468 calculates a half wave in feet
243 calculates a quarter wave in feet

So...
Example 234 divide 1686.6 = .138 close enough
times 12 = 1.66" Ahh, there's are wavelength in inches.

When you take the (times 12) this makes it into inches.

Lets try another..
One of my favorite FM radio stations is on 92.2 MHz

So we take 468 divide by 92.2 = 5.075 feet.

Since this is already above a foot we can leave it for the calculation, but we can do inches too.

times 12 = 60.9" That's the half wave for 92.2 MHz frequency.

When making transformers using coax the velocity factor must be calculated into the formula.

1686.6 MHz = 1.66" (from above) times 80% = 1.32"
That's a quarter wave in RG6 coax. Double the number 1.32 and you get a half wave = 2.64"

This is why I prefer to use the block combiner in my setup. Errors here and you can have all kinds of issues.

By dull I meant that there is no visible earth surface and dark, grey images.
Also, I haven't gotten a full disc image because the Windows version of GRBDump crashes when it tries to save them.
My goal is full disc color images in daylight. I know it will require combining channels.

Yep, you're wanting the visible images and those are big in size. I think a fulldisk is some ware near 450M in size. In a bitmap that's huge.
Any chance that it can save those images in a jpeg, png or gif format?
Default colors on the imagery is grayscale. It depends on how many grayscale colors are available as well to the definition of the detail.
Colors are usually added by the software displaying the imagery, For example on my GVAR system.
There is a histogram that I can open and change the values that represent the temps (on IR) so I can change what grays show and their intensity. It also allows me to add color to the images.
I don't know what GRBDump has, but if you're to get the RGB visible imagery it would have to add the colors during the making of the image.
It takes all 3 visible channels to make that imagery, as explained above 450M per image.
Unless the GRBDump does this on it's own, that's how I'm aware the color imagery is made.
Channels 1,2,3

his is a bit off topic, but there is a new XRIT decoder for Windows

Glad you let us know about that. Thanks.
Thanks for the magazine info as well.

 

[GOES 12 GVAR user]

Quite true, I did gained between 3 to 3.5dB by going to Galaxy (very happy when I saw that), so changes are high as you have recommended on going with the 10'.

That's what everyone here is using. Going any smaller seems not to be a good idea as some margin is a good thing on these. In the PUG manual they were stating 12' is satisfactory. You'll be fine on a 10' dish there. Brett needs the 12' dish at his location.
Later on I will have 12' dish available for GRB, It's currently doing GOES West GVAR.

 

[N6BY]

Brett, if I think what your telling me is the wavelength in coax is longer then free space hold on a moment.....

No, I was saying in the wave guide (the coffee can, square tube, round tube, etc.), not the coax. We agree about the coax -- its shorter there.

This talks about Guide Wavelength: Microwaves101 | Waveguide Mathematics

 

[N6BY]

Good question, I'm actually more inclined on the latter as it could had gotten the devices switched as it was enumerating them or afterwards.

To know for sure, I wonder if it still locks on the ATSC tuner when the antenna cable is removed? If GRBStreamer is getting its devices confused then I will need to fix it.

 

[GOES 12 GVAR user]

In regards the feed, I'm actually testing different options before settling with one, but so far the 3 turn helical has been the one with the most gains.

Highly recommended to go with the coffee can (waveguide) feed over the helical one.
Info for that can be found in posts 47, My version in post 147.

I'm definitely trying GOES12's coffee can feed and see how it goes this upcoming week once built.

If you are to use my version use only the drawing in post 147 as the others I have uploaded earlier have errors.
It will need to be circular polarized to work for GRB. Combined 2 probe style.
Post 12 describes how to do this with coax as Brett is suggesting, and the very recent post I just put up how to calculate the lengths. I use a minicircuits block combiner with my setup and post 147 tells you the part# for it. Remember my feed will only receive 1 of the streams.

I will make a farther recommendation to add a choke ring to get better performance.

Ring out edge should be about 1/4" back from horn mouth.
I should have uploaded this image earlier. I use it with my feeds.

We agree about the coax -- its shorter there.

Good, No need for unnecessary hair loss.
Yep, I saw that info on Microwaves 101.

To know for sure, I wonder if it still locks on the ATSC tuner when the antenna cable is removed?

What is a ATSC tuner?
I think it has something to do with the DVBS-2 receiver.

 

[GOES 12 GVAR user]

What is a ATSC tuner?
I think it has something to do with the DVBS-2 receiver.

Never mind, I found out what it was. Answered my own question.

 

[KWX]

To know for sure, I wonder if it still locks on the ATSC tuner when the antenna cable is removed? If GRBStreamer is getting its devices confused then I will need to fix it.

No lock when the antenna cable is removed.

 

[KWX]

Highly recommended to go with the coffee can (waveguide) feed over the helical one.
Info for that can be found in posts 47, My version in post 147.



If you are to use my version use only the drawing in post 147 as the others I have uploaded earlier have errors.
It will need to be circular polarized to work for GRB. Combined 2 probe style.
Post 12 describes how to do this with coax as Brett is suggesting, and the very recent post I just put up how to calculate the lengths. I use a minicircuits block combiner with my setup and post 147 tells you the part# for it. Remember my feed will only receive 1 of the streams.

I will make a farther recommendation to add a choke ring to get better performance.
View attachment 131014
Ring out edge should be about 1/4" back from horn mouth.
I should have uploaded this image earlier. I use it with my feeds.

...

Great, I'm in the same page as you, I had post 147 in mind when I made that statement. I did opted with minicircuits block combiner. BTW... do you think an aluminum can I have with a 5" diameter and 6 1/2" in length will still work?

Making a choke ring will be interesting to say the least lol.

 

[N6BY]

No lock when the antenna cable is removed.

So it really is locking the Hauppauge ATSC tuner. If you try to stream it, it should give 100% sync errors because it wont find valid BBFrame headers like it would with GRB.

 

[KWX]

So it really is locking the Hauppauge ATSC tuner. If you try to stream it, it should give 100% sync errors because it wont find valid BBFrame headers like it would with GRB.

Literally no lock lol... meaning GRBStreamer will report "No Lock".

 

[N6BY]

What I meant was, it only locks when the antenna cable is connected to the Hauppauge. Or does it only lock when the satellite dish is connected to the TBS5925?

 

[KWX]

What I meant was, it only locks when the antenna cable is connected to the Hauppauge. Or does it only lock when the satellite dish is connected to the TBS5925?

Got it, actually hadn't tried that setup, so just did. I won't get a lock whether the Hauppauge is connected to the antenna or not... so will only get a lock when the TBS5925 is present and the Hauppauge is selected from the list.

 

[N6BY]

Got it, actually hadn't tried that setup, so just did. I won't get a lock whether the Hauppauge is connected to the antenna or not... so will only get a lock when the TBS5925 is present and the Hauppauge is selected from the list.

Thanks for trying that -- it is now a confirmed bug. But I don't know if its a problem in streamreader.dll or GRBStreamer. If its the former then I wont be able to fix it.

 

[GOES 12 GVAR user]

I did opted with minicircuits block combiner. BTW... do you think an aluminum can I have with a 5" diameter and 6 1/2" in length will still work?

Making a choke ring will be interesting to say the least lol.

An aluminum can 6 1/2" length will work but you may want to strongly consider using the probe's position of 1.47" from the back on post 47 due to the shorter length, just like I told Brett you want to keep it as long as you can so not to allow unwanted waveguide modes to propagate.
If you can't/ don't have the length for the choke ring then you can leave it off. But It does help the feed when it's there.
You can make one out of cardboard and tin foil and try it. If it works better then you can consider to make it out of metal.
You must have a terminator on that combiner, just want to make sure you're aware about that.
The two coax cables from the probes must be the same length to the combiner. After that it don't affect the polarization. Use a decent cable to minimize attenuation loss due the the frequency of use. Also I think Brett has built his system on a 75 ohm impedance such as RG6 (good cable)
I build mine on a 50 ohm impedance and make a transition to an F connector at the receiver.
The combiner is 50 ohm impedance so the cabling to it must also be 50 ohm.
If you need a recommendation for connectors and cable I will more than happily give you one. Right there on the East coast. I work with them for my needs.

I won't get a lock whether the Hauppauge is connected to the antenna or not... so will only get a lock when the TBS5925 is present and the Hauppauge is selected from the list.

Should only be getting a lock from the TBS5925.

 

[GOES 12 GVAR user]

it is now a confirmed bug. But I don't know if its a problem in streamreader.dll or GRBStreamer. If its the former then I wont be able to fix it.

So how is Weather 01089 using both streams on your streamer using 2 receivers with no problems?

 

[N6BY]

So how is Weather 01089 using both streams on your streamer using 2 receivers with no problems?

He's using a Digital Devices Cine S2 V7A PCI card. It has two inputs and he is using one for RHCP and one for LHCP. Then he runs two instances of GRBStreamer, streaming to CSPP-GEO (each polarity has a different port). He would have used GRBDump, but it is not fast enough to process both streams at once.

 

[GOES 12 GVAR user]

He's using a Digital Devices Cine S2 V7A PCI card. It has two inputs and he is using one for RHCP and one for LHCP. Then he runs two instances of GRBStreamer, streaming to CSPP-GEO (each polarity has a different port)

Ahh, that's right. Ops that slipped my mind, that card has two receivers. So the streamer only needs to see one device. It's when you have 2 devices that there's a problem or may be.