GOES 16 GRB downlink vs GVAR

[N6BY]

Ahh, that's right. Ops that slipped my mind, that card has to 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.

Yes. I have an old Hauppauge USB tuner. If I can find it I'll hook it up and see if I can figure out where its getting confused.

 

[KWX]

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...

Sounds good and didn't even crossed my mind that I could had built a prototype with cardboard and just use tin foil to test if I would benefit from one or not... which as you mentioned it would.

In regards the combiner, I read your notes on it and interesting enough the ordering page also mentioned the same so got a terminator ordered in case the ones I have might not be good performers. I have a couple SMA F/M extension cables of the same length that I can use for each of the probes to connect to the combiner, from there to the LNA before going through RG6, and finally to the indoor filters/LNAs before processing.

Please recommend away in regards connectors and cables.

Interestingly, I've used that same calculator for HRIT and I always used the freq of operations of 1694.1 as an example. So even if we're dealing with 1686.6MHz we still use 1690MHz? Obviously there's a reason why the specific freq is not used, so just wondering about that reason lol.

 

[N6BY]

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.

If its a bug in streamreader.dll then the only fix will be to remove the unnecessary device.

 

[GOES 12 GVAR user]

If its a bug in streamreader.dll then the only fix will be to remove the unnecessary device.

Yep, I followed that part of the discussion. The Dynamic Link Library is something you don't mess with.

didn't even crossed my mind that I could had built a prototype with cardboard and just use tin foil to test if I would benefit from one or not

You can thank Brett for that idea, He made Quaker Oates famous on here by that idea.

In regards the combiner, I read your notes on it and interesting enough the ordering page also mentioned the same so got a terminator ordered in case the ones I have might not be good performers. I have a couple SMA F/M extension cables of the same length that I can use for each of the probes to connect to the combiner, from there to the LNA before going through RG6, and finally to the indoor filters/LNAs before processing.

Sounds good to me, Keep those probe cables as short as possible. You don't want them like 3'long. Just jumpers. Anything under a foot would be great.
The terminator cap is fairly cheap so it's worth it to get it.

Please recommend away in regards connectors and cables.

Sure, The RFconnection out of MD, Link found Here
They can make custom cables for you and their prices are quite good for the connectors. They carry cable too and more.

So even if we're dealing with 1686.6MHz we still use 1690MHz? Obviously there's a reason why the specific freq is not used, so just wondering about that reason lol.

Well, lets examine your question..
Again lets use the formula for calculating free space wavelength.
We'll calculate to the nearest thousandth of an inch .000" as you measure with a caliper.

234 divide 1694.1 Mhz = .138* X 12 = 1.657"
234 divide 1686.6 Mhz = .138* X 12 = 1.664"

So the difference is .007" of an inch between HRIT and GRB.
I can't build a wavguide to that tolerance, It would have to be machined. The can it's self will vary that much in the sun on a hot day.
So in the world of waveguides 1690 Mhz is well in the usable frequency range of all this we're doing.
Now you try to use a 2.4Ghz waveguide for this, it won't work as the 1.6Ghz is to large for the smaller waveguide to propagate in. It's below the cutoff frequency.
The opposite happens when you take 1.2 Ghz waveguide and try to use it a 1.6 Ghz. The 1.2 is bigger than the frequency of interest so 1.6 propagates in this guide but it don't do it well. It will cause several unwanted waveguide modes to be present and when talking circular polarization this is bad as these unwanted modes can cause interactions that mess up the original waveform.
You want a guide that allows one mode to be present, It don't mean that other frequencies above can't propagate in it. But those frequencies are not (preferred) for that guide. In simple terms a correct waveguide helps act as it's own high pass filter as most frequencies below the cutoff are not allowed in.
And the frequencies above it are attenuated to a point, that's why I prefer to use a longer guide as (mentioned before) it don't allow unwanted modes to propagate. It's length helps eliminate the unwanted mode. I was told that by Paul W1GHZ and have followed it to a "T".
Waveguides are not super narrow bandwidth devices (or high Q). Any guide (can) that works on WEFAX, EMWIN, HRIT, GVAR will work for this. It's just a polarization issue.

 

[KWX]

Yep, I followed that part of the discussion. The Dynamic Link Library is something you don't mess with.



You can thank Brett for that idea, He made Quaker Oates famous on here by that idea.



Sounds good to me, Keep those probe cables as short as possible. You don't want them like 3'long. Just jumpers. Anything under a foot would be great.
The terminator cap is fairly cheap so it's worth it to get it.



Sure, The RFconnection out of MD, Link found Here
They can make custom cables for you and their prices are quite good for the connectors. They carry cable too and more.



Well, lets examine your question..
Again lets use the formula for calculating free space wavelength.
We'll calculate to the nearest thousandth of an inch .000" as you measure with a caliper.

234 divide 1694.1 Mhz = .138* X 12 = 1.657"
234 divide 1686.6 Mhz = .138* X 12 = 1.664"

So the difference is .007" of an inch between HRIT and GRB.
I can't build a wavguide to that tolerance, It would have to be machined. The can it's self will vary that much in the sun on a hot day.
So in the world of waveguides 1690 Mhz is well in the usable frequency range of all this we're doing.
Now you try to use a 2.4Ghz waveguide for this, it won't work as the 1.6Ghz is to large for the smaller waveguide to propagate in. It's below the cutoff frequency.
The opposite happens when you take 1.2 Ghz waveguide and try to use it a 1.6 Ghz. The 1.2 is bigger than the frequency of interest so 1.6 propagates in this guide but it don't do it well. It will cause several unwanted waveguide modes to be present and when talking circular polarization this is bad as these unwanted modes can cause interactions that mess up the original waveform.
You want a guide that allows one mode to be present, It don't mean that other frequencies above can't propagate in it. But those frequencies are not (preferred) for that guide. In simple terms a correct waveguide helps act as it's own high pass filter as most frequencies below the cutoff are not allowed in.
And the frequencies above it are attenuated to a point, that's why I prefer to use a longer guide as (mentioned before) it don't allow unwanted modes to propagate. It's length helps eliminate the unwanted mode. I was told that by Paul W1GHZ and have followed it to a "T".
Waveguides are not super narrow bandwidth devices (or high Q). Any guide (can) that works on WEFAX, EMWIN, HRIT, GVAR will work for this. It's just a polarization issue.

Thanks for all the great info.

 

[GOES 12 GVAR user]

Glad I could be of help.

KWX, you're helping us by trying the TBS5925 and the waveguide feed along with Brett's streamer software.
With what you get out of that setup I can compare it to my setup and the difference between the septum feed that weather 01089 is using. Providing that you are using the 10' dish.
This will give me a real good idea of the antenna performance of GOES 16.

 

[GOES 12 GVAR user]

Hey Guys, I just found an item of great Interest!

Brett, at page 3 post 44 you posted the ebay amp you are or were using part# LNA-V1.0
This amp is not the best amp for the first stage as it has a 2 dB or even 3 dB noise figure.
I Have found a similar amp that I use here to (DEMI UTRLA LNA) for a much better price.

The first is part# RF AMP V2.0 NWDZ
The next (I like better) same specs. SPF5189 RF Amplifier SG
Ebay Part RF AMP
Ebay Part SPF5189

These amps work from 50-4000 MHz have gains for our use of 19 dB or so.
But the best part is that the noise figure is .6 dB.
This is huge as that is want you want for the first stage amp for GRB. They work on 5V DC and are near $10.00.
The latter part# has a bit of a shield over the amp which is good. I payed 12 times more for mine from DEMI.
If these do as they spec then you are getting the lowest noise figure that is possible in the first stage with decent gain.

 

[GOES 12 GVAR user]

@hdoverobinson from the Open Satellite Group sent me a Nooelec saw filter/LNA optimized for 1680MHz.

Back on page 8 post 148,
Been doing some back reading and got a question for you Brett.
Did OSG tell you what they did to optimize the Nooelec SAW filter/LNA?
That unit (as factory) is made for the 1.5 Ghz band, the upper 1.6 Ghz we use here is not in the passband.

I'm looking at different blocks right now and caught this as you have been recommending it. That why the amps got posted earlier.

 

[N6BY]

...
Brett, at page 3 post 44 you posted the ebay amp you are or were using part# LNA-V1.0
This amp is not the best amp for the first stage as it has a 2 dB or even 3 dB noise figure.
I Have found a similar amp that I use here to (DEMI UTRLA LNA) for a much better price.

The first is part# RF AMP V2.0 NWDZ
The next (I like better) same specs. SPF5189 RF Amplifier SG
Ebay Part RF AMP
Ebay Part SPF5189

These amps work from 50-4000 MHz have gains for our use of 19 dB or so.
But the best part is that the noise figure is .6 dB.
This is huge as that is want you want for the first stage amp for GRB. They work on 5V DC and are near $10.00.
The latter part# has a bit of a shield over the amp which is good. I payed 12 times more for mine from DEMI.
If these do as they spec then you are getting the lowest noise figure that is possible in the first stage with decent gain.

I agree it was not optimum for this as it only goes to 2 GHz and high noise.

I said 'was' because I accidentally powered the amp pictured in post 44 with 12 volts (it takes 5). I was switching back and forth with the 64 dB amp that takes 12 volts when I made that mistake.

So the LNA-V1.0 is toast. Last week I ordered some others to try. They are rated 50 MHz to 4 GHz, 50 MHz to 6 GHz, and 10 MHz to 6 GHz. The latter arrived today. It is USB powered and I haven't tried it yet.

I will be trying them all and seeing which works best.

 

[N6BY]

Back on page 8 post 148,
Been doing some back reading and got a question for you Brett.
Did OSG tell you what they did to optimize the Nooelec SAW filter/LNA?
That unit (as factory) is made for the 1.5 Ghz band, the upper 1.6 Ghz we use here is not in the passband.

I'm looking at different blocks right now and caught this as you have been recommending it. That why the amps got posted earlier.

The Nooelec 'Sawbird' and 'Sawbird+' passband is centered at 1675 and was specially designed with NOAA reception in mind.

They used to make one for Outernet at the around 1.5 GHz.

 

[GOES 12 GVAR user]

I said 'was' because I accidentally powered the amp pictured in post 44 with 12 volts (it takes 5). I was switching back and forth with the 64 dB amp that takes 12 volts when I made that mistake.

You know they don't like that very much. So you let the smoke out. That's never a good thing. Well at least their cheap enough to replace. Unlike mine that would be painful. But been there done that.
However the DEMI units go to 15V DC which is very nice. Something to consider when using these 5V amps.
If you can make simple circuits, build yourself a 5V regulator circuit. The IC is cheap and rated at 1 or more amps can power all your amps, modules.

 

[GOES 12 GVAR user]

The Nooelec 'Sawbird' and 'Sawbird+' passband is centered at 1675 and was specially designed with NOAA reception in mind.

They used to make one for Outernet at the around 1.5 GHz.

Ahh, okay I have to do some more back reading as nothing is showing up in the search and I remember you telling me how you got it.

 

[GOES 12 GVAR user]

I have to call or email Nooelec, found that.
I there a part # for that?

 

[GOES 12 GVAR user]

I there a part # for that?

Didn't know if it had a specific part #, Looks like SAWBIRD or SAWBIRD+
I know what to ask now when I get to that point. Thanks.

 

[GOES 12 GVAR user]

I will be trying them all and seeing which works best.

It can make a big difference here, this is the most critical gain stage in the string. Really hope you get a good match and get it working.
Bout how long (average) does it take for them to ship to you?

 

[KWX]

Glad I could be of help.

KWX, you're helping us by trying the TBS5925 and the waveguide feed along with Brett's streamer software.
With what you get out of that setup I can compare it to my setup and the difference between the septum feed that weather 01089 is using. Providing that you are using the 10' dish.
This will give me a real good idea of the antenna performance of GOES 16.

Glad to help out. Yeah, will let you guys know when I get the can version setup up and running as I'm still waiting for parts. 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). So given the aforementioned I'm inclining to believe that the can version to be built, will perform quite well. 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.

 

[KWX]

Hey Guys, I just found an item of great Interest!

Brett, at page 3 post 44 you posted the ebay amp you are or were using part# LNA-V1.0
This amp is not the best amp for the first stage as it has a 2 dB or even 3 dB noise figure.
I Have found a similar amp that I use here to (DEMI UTRLA LNA) for a much better price.

The first is part# RF AMP V2.0 NWDZ
The next (I like better) same specs. SPF5189 RF Amplifier SG
Ebay Part RF AMP
Ebay Part SPF5189

These amps work from 50-4000 MHz have gains for our use of 19 dB or so.
But the best part is that the noise figure is .6 dB.
This is huge as that is want you want for the first stage amp for GRB. They work on 5V DC and are near $10.00.
The latter part# has a bit of a shield over the amp which is good. I payed 12 times more for mine from DEMI.
If these do as they spec then you are getting the lowest noise figure that is possible in the first stage with decent gain.

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.

 

[N6BY]

It can make a big difference here, this is the most critical gain stage in the string. Really hope you get a good match and get it working.
Bout how long (average) does it take for them to ship to you?

I got mine shipped from a guy on the East coast. Not sure how long it takes to order from Nooelec.

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

 

[GOES 12 GVAR user]

I got mine shipped from a guy on the East coast. Not sure how long it takes to order from Nooelec.

I wasn't so interested in the shipping on that filter since it's from the US. I was more interested in how it take to get those amps from China to you Brett. The ones off ebay. Those China Epackets sometimes are slow.

 

[N6BY]

I wasn't so interested in the shipping on that filter since it's from the US. I was more interested in how it take to get those amps from China to you Brett. The ones off ebay. Those China Epackets sometimes are slow.

This LNA took about a week. The seller is in Canada but shipped from New York: Low Noise Amplifier 10 - 6000MHz RF LNA Gain 20dB; USB; *Operates to 8GHz* | eBay
Still waiting for this one from Hong Kong, but its in Illinois now. Ordered on the 23rd: 50MHz-6GHz UHF 2.4G Broadband Low Noise Amplifier RF LNA Amp Module 20DB VHF HF | eBay
And this one, also from Hong Kong, is still not listed as to its location: 50MHz to 4GHz 20dB Low Noise LNA RF Broadband Amplifier NF 1.3dB HF VHF/UHF | eBay