GOES 16 GRB downlink vs GVAR

[GOES 12 GVAR user]

Here is the pages of constructing the septum feed choke ring. Any changes that will need to be made will be made later in another post.
N6BY has dimensions of a septum feed that he uses, his dimensions would work for this as well. This feed is converted from the RA3AQ septum feed.

Tools:

Tin snips (straight blade style)

Stainless steel wire brush (must have)
Drill bit set, includes fraction sizes
Centering punch
Hand nibbling tool

Square
Pencil (something to write with)
Straight edge (such as a yardstick)
A caliper (can use a ruler)
large Compass Divider Caliper (preferred)
Mill file (8 - 10")
Propane torch
Wood glue
sandpaper or block
Clamps (small quick grip and or vise grip style)
(spring style fine for jig base)
Also band style or long worm (hose style) clamps for the
choke ring strip.

Materials:
1/2" Poplar square dowel rod
Enough to make 2 sticks at least 14 3/16" long
1/4" dia oak dowel rod.
Enough to make 4 sticks 4 3/16" long
Super alloy 1 from Muggy weld

Aluminum parts:
14 3/8" X 14 3/8" .040" Aluminum sheet
*4 5/8 X 48" .040" Aluminum strip

*This strip can be .030" to make the fabrication easier.

Hardware:
2-56 S.S Screws 3/16" long
2-56 S.S. Nuts

Manufacturer for my feed parts
Puritian Mfg.
Omaha 402-341-3753
Salesman: Mike
Any metal mfgr that carries aluminum and that fabs it should be able to do this. Building this choke ring is not a hard task but does require some hands on skills.
Using of tin snips and drills along with propane torch are needed to make this part. Cost is dependent on the tools and materials that are
already available. The more you have already, lower the up front cost. Most dimensions are standard but there are some in decimal format. If one needs a decimal conversion chart you can find it here. Link
The basic cost for the choke ring materials are $30.00 or near this. This gets the basic parts made for the ring. This don't include any tools or solder needed to build the ring.
I used Muggy weld super alloy 1 for the solder on this. The reason I used this is the low temp needed to melt the solder at 400 deg F. There's other rod out there that melts at 800 deg F. but this heat will distort the thin aluminum material. If you are good at using it then by all means use it, but I don't recommend it.
The low temp solder is fine for this job and high strength is not needed.
All holes drilled are pre punched first so that the drill bit don't wander from the hole. The punch I used is a metal pencil scribe that has a hardened sharp tip that makes an easy dimple in the aluminum for the starting of drilling. I start with a small drill bit then when the hole is made in the material I go to the size I want for the final size.
The first step is to study the dimensions sheets so that you are familiar with them. Read through this manual as well to get familiar with the steps. This will help the assembly process move along.

Starting things off:
Since you will need a jig to assemble the choke ring I figure this is a good place to start construction.
To make the jig will require 1/2" square poplar dowel & 1/4" round oak dowel rod (I got mine from the big home supply store). You need enough rod to make all the parts listed, Part 1 & Part 2 along with the 4 vertical rods.
I wanted to make a jig that would be easy to replicate and cheap. Dowel rod fits this nicely and it's pretty cheap. I wanted poplar for the base and for making the slots I used a hand saw and a wood chisel. The soft wood with a sharp chisel makes quick work of the task. I likewise used oak for the rods as it's strong and durable.
All this is put together with just some wood glue, no fasteners are needed.
Start of with cutting Part 1 & and Part 2 (the base of the jig) from the 1/2" square rod(s). Then make a center mark and measure 1/4" off that mark each side. Mark 1 1/4" from all the ends on the same side as the center mark is on (these are your vertical holes).
To make the slot I used only hand tools. If you have a tool that can make the slot, then by all means use it. But you will want to keep the 2 base parts snug when put together as the friction fit is part of the strength of the jig.
I used a hand saw to make mutli cuts a 1/4" deep in the square rods and used the chisel to remove the material, if I needed more removed then the chisel was used after the first cuts. As I neared the desired result I used a file to remove the final bit of wood to get the fit I wanted.
Once the 2 parts are able to fit together then drill the 1/4" holes on all 4 ends for the vertical rods, you may need to go slightly above that size of bit and work it in the hole to make the 1/4" dowel rod fit in the hole snug not tight (it must be able to move). You should be able to tap on the rod to move it. The 1/4" dowel rods are slightly shorter then the height required so they can be adjusted for final fit. I used a caliper to measure the height needed then glued the rods in place by running a bead of glue around the outside when I got them where I wanted them. let glue dry.
With the glue dry slightly round the ends of the square rod, just buy knocking the corners off a bit with some sandpaper.
I used a carpenter's quick square for the base, put glue in the slots and clamped it together with the square clamped as well. Wipe off any glue that squeezes out. let dry.
When glue drys remove square and you should have a unit that looks like the picture below, set it aside.

Making the choke ring flange:
Take the 14 3/8 X 14 3/8" aluminum sheet and make a center point by going from corner to corner making a "X" where the lines cross. Use this center point and lightly punch a dimple so that it can be used as a pivot point. I used a large Compass Divider Caliper with the points set to the radius of the ring OD (7.07"). The one point of the divider in the center dimple you punched and the other will lightly scribe a line in the aluminum sheet making the OD of the flange.
When done with making the scribed OD line, make a line to divide the circle in 2. This reference line marked will be used to make the feed mouth opening. If you want you can mark that out now. Use the reference line and make another crosshair at the center 90 degrees from the reference line. This is the feed mouth center line. Measure the width of your feed mouth and divide it by 2. Mark the 1 half on one side of the line then mark the
other half on the other side of the line. Do the same with the height of the feed mouth. Use the smallest measurements from the feed opening and finish the size after the first cuts have been made. Otherwise leave this step until the flange has been cut out.
The reason I give no measurements here is your feed may very slightly from mine and you want the flange to fit very close, so it's best to use your own measurements here.

Use the tin snips to cut away the scrap corners keeping about a 1/4" off the scribed line made in the step before. The goal is here to remove material slowly so that the final cut goes smooth. I found that like the septum, removing material until a 1/4"to 1/8" is left makes an easy to control cut. Make the final cut when all the way round the dia is left with that margin. Take time with the cut and constantly check to make sure you on that scribed line. When done you will have a round sheet of aluminum, use the mill file lightly and remove any edges and burrs that remain after the cut.

If you haven't marked out the feed mouth yet now is the time.
I used a hand nibbling tool to cut out the feed mouth from the aluminum sheet. Start with a hole so the tool can fit through and begin to nibble away. May have to give your hand a break every so often as it can get a little sore after a while.

Once you get the first cut made then you can follow the line staying on the inside of it and make the final cuts. Don't get too worried about any of the rough edges as when done use a mill file to clean it up and work the material to the final fit so that the feed mouth can fit through the hole.

 

[GOES 12 GVAR user]

Adding the choke ring strip:
Do these steps on a flat surface.
You have some options here as if you want to use the .030" or the .040" sheet thickness. If you decide to use the .040" then you will need to pre form it before putting it over the jig. Cause if you don't and do it like I did the first time get ready to have part of the workbench cleared off in a hurry if it gets away from you.
Preforming is just coiling up the strip and tightening the coil so that it is preformed slightly before trying to put it on the jig. Takes away alot of the spring energy with it. You will probably have to do the same with the .030 though it shouldn't be as bad but be careful not to kink it, same with the .040".
The clamps used here are worm style as seen in the picture below. I found these at The Homedepot, they have some very long ones. Otherwise you will have to join several clamps together to make it all the way around and still have some "loose" room to adjust and tighten up. I had to use 2 put together to get what I wanted.
The aluminum strip should be 48"long, I removed 2 13/16" of it for my final size to get a 1/2" of overlap. Use a square to make a line and trim it with
the shears. Also mark the overlap measurement and draw a line for reference.

If you decide to make your own length here's how I did mine.
Put flange on top on the oak dowel sticks (try to center it on the jig) and wrap the strip around the flange OD keeping the strip on the flat workbench not on top of the jig base. Have ready 2 band worm clamps and when you get the strip wrapped enough slide a clamp from the top side down around and past the flange towards the workbench surface, take the other clamp and side it the same way to just past the flange. The clamps now hold the strip in place around the jig and flange.
Tighten the clamp closest to the flange abit then go to the lower one keep doing this until the strip is over lapping. Then keep tightening the upper clamp until the strip is snug (not tight) around the flange, the lower clamp may get so loose that it falls off. Tighten lower clamp until the top edge of the strip is straight across the seam, the clamp may be quite lose. Repeat this step and tighten the upper clamp until it's tight pulling the strip tight against the flange edge. Keep the top edge straight in the final tightening process.
Here's a weakness to my jig, due to the lack of support around the outer strip edge, if you over tighten the lower clamp the strip will be a smaller dia at the bottom then at the top resulting in a kink in the seam of the overlap. That's why I tell you to keep that top edge straight as when it is then the dia should be as well from the front to the back. Once the strip is tight to the flange then measure the overlap desired and make a mark on the long overlap.
Remove the strip and use a square to the mark and make a line and trim it with the shears. Also mark the overlap measurement and draw a line for reference.
Now this applies to all, repeat the clamping process to put the strip back over the jig and flange, when you tighten the lower clamp and the proper amount of overlap is achieved use a visegrip or quick grip clamp to hold it in place. Continue to tighten the upper clamp until it's tight around the flange. Your seam line should be straight as well as the top edge. If it's not then you need to make some changes to the lower clamp's position.
When you get it lined up then you can remove the lower band clamp and put a vise grip clamp on the top of the seam. Then remove the upper band clamp.
Now the seam is exposed so you can mark and drill the holes needed to finish the ring.

I did not punch these holes just straight drilled them.
Mark the hole locations, I used 4 screws to fasten the seam together. Two screws on the edges and 2 roughly in between. Location is not critical here just try to keep them centered in the overlap. Use a small drill bit to drill the holes (1/16"). Work slowly, you may need to adjust the vise grip clamps a bit to drill the holes. The top screw will be a bit tight due to lack of space there.
I originally had the idea to soldering the seam but found this could be a big problem later in the fab process, so I decided to use fasteners here.
Once the holes are drilled the (I recommend) put one of the band clamps back on and tighten it then remove the vise grip clamps then you can easily remove the strip again.
With the strip now off the jig and laying on the work surface finish drilling one side of the holes to 3/32", drill the other side hole slightly oversize to 7/64".
Clean up the burrs and hole edges. As well and any burrs on the strip.
Make sure that the flange is properly set on the jig, making sure that the way you marked it out is properly positioned. Again put the choke ring strip back around the jig and flange, proceed with the steps to tighten it up.
One the holes begin to align put the 2-56 X 3/16" screws in and sung up the nuts so the strip can still move, keep doing this until all 4 screws are in place with nuts. When a 4 are in the you can tighten them up.

Remove the band clamps and the whole assembly should be able to be removed off the jig. Tension should hold the flange in the ring.

 

[GOES 12 GVAR user]

Soldering:
You could do this step before you assemble the ring onto the flange for the final time installing the bolts. But I did it after so I didn't have to worry about touching the cleaned soldering surface. With the assembly off the jig push the flange from the ring so that it comes out. With it out wipe any oils from the bonding surfaces, clean if needed.
Use a stainless steel wire brush to clean and prep the bonding surfaces (around flange edge and ring upper edge. When done wipe with clean cloth.
Put ring back on jig as it was when you assembled it as well put the flange back in the ring as you assembled it. Use the jig to set the depth of the flange. Press several times to make sure that the flange is flat on the jig vertical rods. There should be a constant or near constant depth all the way round the ring.
Move the ring to the area that it is to be soldered, I had mine set on some steel plates along with the jig to keep it off the work surface.
Spread some flux in the solder joint and then begin heating up the part. Heat the ring then the flange though heat will transfer between the two the ring will require more heat then the flange. Keep heating between the 2 parts until the flux get it's color indicating the proper temp for solder melt (see Muggy weld directions).
Melt solder in joint careful that in any open gaps it don't run down inside of the ring past the flange, shouldn't be a big issue. As you heat the flux is drawn ahead of the joint but keep putting flux on the solder rod as you melt it and apply flux ahead of the solder while heating with the hand held torch. Keep an eye on the setback from the top edge as the flange is heated it may warp slightly and very the depth as you solder it. A good idea may be to do what was done on the feed's back plate with the clips on the top edge so the it can't move much. When done let cool. Clean flux with some denatured alcohol and then warm water.

If you built the feed using the 2 channels then you will have to remove the screws/nuts to slip the flange down the feed to the distance marked earlier.
Again clean the solder bond area with a clean cloth and a stainless steel wire brush. Wipe clean.
With the choke ring flange at the proper depth now you can reinstall the 4-40 screws that were removed from the seam and set it, solder it.

In my pics I used foil tape to hold the choke ring in place, this is for testing only not to be left there. I highly recommend soldering the choke ring to the feed body.
Set both on a flat surface and use an 1/8" spacer to lift the choke ring off that surface, this sets the setback of the choke ring.
Apply flux then use the hand held torch and heat the feed body up then work between the feed body and the flange as you solder the joint just like you did with the flange on the choke ring. Solder the 3 sides on each feed body leaving the seam area alone. let cool when done.
Clean the flux from the joint using as little denatured alcohol and then warm water as needed. You don't want the water in the feed if possible. Though it shouldn't hurt it.

Proceed with the finishing steps from the feed instructions...
I recommend to use JB weld (link) to go in the gap around the edge of the back plate to seal it. I don't recommend to solder it as the heat required will molten the solder on the septum and could result a bad outcome. Also use some JB weld on the top seam of the wavegide to keep any water out. If you built the septum and spacers tight enough together then this may not be a problem.
I recommend to paint your feed/choke ring white, why.. white is a heat repelling color so it keeps the feed as cool as it can be in the hot sun. Aluminum expands under heat so your want to keep that low, also the cooler feed results in a lower noise figure. Yes that does make a difference.
Use a good spray paint (Rust Oleum, Krylon or similar) to finish your feed. Put it on in several coats to make a solid thick outside shell. Of course mask the connectors so the paint stays out of them and painting the inside is not needed. Do paint the inside of the choke ring.
The paint does something else, the choice of aluminum body and stainless steel hardware does have it's issues. The two metals are dissimilar and can react with each other. Especially if water (an electrolyte) is present.
The result is galvanic corrosion. A good heavy coat of paint will help keep that to a min. so your feed choke ring should be intact for years to come.
And finally put some foam board in the mouth of the waveguide to keep the bugs and other pests out.

 

[GOES 12 GVAR user]

just smoke. It's blowing to the southwest, and I am in the middle of it.

The state of Cal is on the Eastern side of a strong mid to high level High pressure system, We here have been on the low pressure side of the system and getting one shot after another of arctic air coming down. But that pressure system is pulling the smoke to the SW like that and that pattern not going to change much in the long term. The situation is bad out there, take care the both of you.
The smoke looks to be at least drifing to the East now from what I see on satellite.
One of the very powerful tools onboard the GOES spacecraft, great looking image but very bad situation what they show.

 

[GOES 12 GVAR user]

For the final installment of these uploads I plan to show you how I'll make my preamp block for this. I will be able run on 7-30V DC and be powered using an F connector and RG58 or 59 cable.

 

[GOES 12 GVAR user]

Brett updated GRB Imager to 1.17 due to issues with the TBS 6903 card having CADU errors for an unknown software reason. Since he updated the program the change has been great as to results. Screen shot shows 14.5 Million frames with out errors, the actual number is 21 million frames due to a reset that happened with "unwanted furry help".
The feed seen in the posts above is what was used to get these results. Thanks again to Brett for all the hard work on this program.
Program running on an HP elite computer with 8 Gb of ram with a quad core Intel processor running Win 7 Pro.

 

[GOES 12 GVAR user]

And here should be the beginning of the preamp block for GRB.

 

[GOES 12 GVAR user]

I finished putting a slide show together with the images I got setting up Wed. Same data from the screen shot above shows.
This is the link for all 5 channels I got for the CONUS loops, meso sector loops. This was made by another slide show software not by the one on GRB Imager.
The link below will take you to my google drive and the file must be downloaded and opened, it's an executable (exe) file format made by Irfranview.
I will upload the Meso sectors loops here a little later.

CONUS loop files: CONUS 11_14_18
MESO 1 loop files: Meso 1 11_14_18
MESO 2 loop files: Meso 2 11_14_18

CH 14 CONUS

 

[N6BY]

GOES-17 (the new GOES-WEST) is now in place at 137W and sending images. The image below shows the smoke from the Camp Fire as seen from GOES-17. I am located where the small yellow 'x' is. Smoke is not as bad as the past several days.

I'm using my 8.5' BirdView with a new lighter septum that I recently completed. The 8.5' dish signal is 1 to 2 dB lower than my 10' dish, but I'm still getting 8 to 10 dB, which is good enough.

 

[N6BY]

Here is one of the first Full Disc images I received from GOES-17 today. In the full size image (10848x10848) you can see the Hawaiian islands.

In the lower image, New Zealand is visible along with some very interesting clouds to the east of it.

 

[GOES 12 GVAR user]

GOES-17 (the new GOES-WEST) is now in place at 137W and sending images.

I am located where the small yellow 'x' is. Smoke is not as bad as the past several days.

Goes 17 is in test out period, somewhere in early Dec. if every thing checks out it will be declared operational GOES West.
That "X" is tough to see, but since I know where you are located I see it. Ya, that smoke does look a lot better.

I'm using my 8.5' BirdView with a new lighter septum that I recently completed.

With you in a much better location for GOES West you can get away with a 8.5' dish. New feed looking good.

Here is one of the first Full Disc images I received from GOES-17 today.

Those full disk images are striking. I notice very quickly the 2 strong storms systems that are over the Pacific ocean. These will be changing the pattern a bit as that ridge that is over you is expected to be moving East and warm us up a bit here in the Midwest.

In the lower image, New Zealand is visible along with some very interesting clouds to the east of it.

Those clouds look to be thunderstorms under very weak flow so the anvil is very slowly blowing to the East which gives such the "wispy appearance".

 

[N6BY]

...
With you in a much better location for GOES West you can get away with a 8.5' dish. New feed looking good.
...

Its about the smallest usable size dish here. 1 in 10 million frames have CADU errors. I have not yet fine tuned the septum placement or the probe lengths. That should help.

Timothy, thanks for the choke ring build info. Have you had a chance to try it out yet? I am curious to know how much it improves the SNR.

...
Those full disk images are striking. I notice very quickly the 2 strong storms systems that are over the Pacific ocean. These will be changing the pattern a bit as that ridge that is over you is expected to be moving East and warm us up a bit here in the Midwest. ...".

Rain is predicted for Wednesday through Saturday or Sunday. Really looking forward to an end to the fires/smoke and being able to breathe decent air!

 

[GOES 12 GVAR user]

Its about the smallest usable size dish here. 1 in 10 million frames have CADU errors.

Still not bad for that small of dish. Lot better then where I was.

Timothy, thanks for the choke ring build info. Have you had a chance to try it out yet? I am curious to know how much it improves the SNR.

Yes, the last picture you see of the instructions I show the feed and ring together but as I said I used aluminum foil tape to hold it together as I still want to change the septum in the feed for the proper size. My septum is 1" short as of the postings I have done.
I'm glad you brought this up. My performance has been 10.60 peak with out the choke ring, the results have been no less 11.30 and up to 11.60 so I would say a 1/2 dB SNR has been achieved from it, but...
The choke ring's performance is dependent on the dish size according to Paul (W1GHZ). The reason for this is simple as the choke ring adds to the dish's shadow. So he recommended the the choke ring be used with dishes no less then 20 waves across for good performance. So that equates to an 11' dish. It does work good with a 10' dish but when I get this on my 12' dish it should be quite good. In your case it may very well help the SNR but I would recommend that you build a mock up out of cardboard before going to the work of the final version. Card board with foil glued to the surface will work just like I did with some of my tests. I used hot glue to hold the card board together. Make sure the foil is making good contact to the feed's body. The foil tape idea may work for mating the two together as well, like I did. With the smaller dish size there I would want to be sure that it wouldn't hinder what you have before spending the money/time on the aluminum sheet.

Rain is predicted for Wednesday through Saturday or Sunday. Really looking forward to an end to the fires/smoke and being able to breathe decent air!

I wouldn't hold your breadth yet (bad pun).
It's going to have to give some decent rain to counter that dryness in those forests, it even looks quite dry in your dish picture there. So fire danger could remain high.
For the people in the burn scar areas that has it's own problems. But the movement of the pressure system should change the wind direction and that will most certainly help in your area. I kinda know (though not as bad) what you are dealing with. Watch GOES when the spring gets here south of me in Kansas, they burn the flint hills and with that South wind all that smoke from those fires comes up here. Smells like smoke and looks like haze in the air. Just yummy.

 

[GOES 12 GVAR user]

This is an update to the feed construction info that I posted. I found that the book that I got the info from was wrong so the converted measurements was wrong, the good news that it was just one measurement that was wrong.
The septum length overall should be 9.29" NOT 10.29". I made a new septum for the feed to those dimensions and found out that it's waaay off. It took the SNR from 11.30 to 8.00 or slightly less. If you have been reading this forum you would know that I made an error when I built the septum feed and the septum length was wrong due to my measurement, I found solely by mistake that my error is correct for the frequency used. So make the septum 9.29" long from the lowest step to the back plate and it will be right on the dot. All other info is correct and no issues found, feed is currently in use.

Other notes:
I also found that even the low tep solder of Muggyweld Super Alloy 1 does cause some distortion in the .040" aluminum sheet and it seems to be hard to get away from, though you can bend the sheet back to the original shape or layout after the the soldering is finished. This was particularly evident when I soldered the back plate of the new septum. By using the small screw driver to push down the center bow out and flatten it to the septum caused the sheet to twist a bit, again I was able to flatten it out pretty well afterwords. This happened again when I soldered the choke ring to the feed body. The choke ring sheet bulged in the long length center as it was heated but didn't affect anything else.
Maybe a preheat of the sheet may help solve this?
Regardless it's not a huge issue in the fab process. Just watch as you heat to try to keep it to a min.

Soldering tip:
I found a method that may be helpful to solder with Super Alloy 1. If you have ever plastic welded by hand with rod then you will know what I'm talking about, others see here: plastic welding video

start at 2:57 through 3:34 pretty much just like that, heat the aluminum ahead of the joint and the rod just where it contacts the parts. Too hot and the rod will melt before it gets to the joint. Instead of the hot air welder he is using, you use a propane torch set to mid setting. Again you have to stop about every inch to put more flux on.
I found that after heating the parts to the desired temp (flux color) taking the rod and driving it into the joint while heating the parts just ahead of the rod will drive the molten solder into the joint and make a great bond with out solder blobs in places. You do have to put flux down every so often before the solder bead. This is where you can get a blob, otherwise it looks just like a bead of solder around the joint. It will fill the small gap and not run inside of the joint. I also found that as Muggyweld states that the flux will indeed clean up by water, if you overheat the flux then you may need to
use denatured alcohol.

 

[GOES 12 GVAR user]

An update to the progress of the GRB station here
Brett (N6BY) has been updating GRB Imager and making it even better.
The last few updates include being able to extract a smaller part of the image out of the Fulldisk and CONUS.
This acts to zoom in on the area of interest. Also it's easy to watch slideshows of the images this way as it uses much less memory to run the slideshow.
He also put in an auto lock feature so the coax don't have to be disconnected, if you have a strong signal input then it takes a little more to get it to work.
There is also a timestamp option for the images.
He did a bugfix to GRB Imager crashing after creating a lot of images. I have got my station up and running now in a pretty much
constant image ingest. I well surpassed 220 million frames several times.
Using the septum feed that I posted for construction and the choke ring I get an average 10.65 SNR here with 77% quality. It can vary by about a 1 dB SNR over 24 hours.
My system is made of these blocks.
*10' C band mesh prime focus dish.
*Septum feed
AMP block:
*Nooelec SAWBird+ for GOES and a spf5189z (Ebay found amp)
(more to come on the amp block)
2 coax cables:
*Cable 1 is for the RF and is 120' LMR240 with SMA connectors
*Cable 2 is for the preamps power feed and is 120' of triax with an F connector on one end.
*Receiver is a TBS 6903 dual tuner card and a Holland VBC-HR dc blocker
HP elite computer with 8 Gb of ram with a quad core Intel processor running Win 7 Pro.

The system has been working great on the single polarization and have had almost no errors to speak of. The software is running very well. I have had only one instance of the receiver unlocking and that was due to NOAA resetting the GRB signal not the receiver.
More may be to come here as Brett has been working on the software and making it better and better.

Ok, now a bit on the amp block.
I had to revise my thinking on the power option on this as the voltage regulator inside the case at the dish wasn't going to work,
heat was going to be a big problem and lead to early failure of the device.
So I ended up just using a USB cell phone charger 1 amp or better to power the amp block, the good news is the SAWBird and the spf5189z take 5 VDC to power, the same voltage that the charger is regulated to. What's nice about this is the cell charger is easy and pretty cheap to come by.
Taking a USB charge cable and cutting the end off that isn't needed then noting what side is positive is and soldering some wire to the USB ends is the power to coax device, 5V + to center conductor and minus to shield.
The triax should have been RG59 but the supplier sent me triax in place of that, boy was I surprised when I saw that. All the triax does is take the 5 VDC to the amp block through the F connector. Nothing more. There's about a .5 volt drop on the line at the amp.
Using coax as a voltage line has the advantage of resisting interference on the 5 VDC line, I also put a capacitor (a filter)
across the line inside of the amp case to keep the DC power clean as possible.
I left the cardboard and tinfoil on the amps when I put them in the case, this way they are shielded from each other and can't touch anything that could short them out. All I had to do was route power wires out of the box that the amps were in.
A short piece of LMR 100A connects the two together.
I used foam and peanuts (packing style) to keep everything from moving around in the case.
The amp works very close to as good as what I tested with, The cable shows no loss noticeable in SNR with the 120' length.
The power is connected to the amp through an installed F connector in the case.
The final part is to seal the coaxes going into and out of the case with some caulk to make it as weatherpoof is possible.
These pictures don't show the final hookup of the amps but shows more of the construction and layout in the case, The small board in the corner is not used as that was the regulator board that wouldn't work for this (explained above)
Cables going into and out of are 2' long LMR240 flexible version. Has a stranded center conductor for more flex.
I may upload a few more final pictures later but this is the general idea of how it's made.

 

[GOES 12 GVAR user]

Some of the final pictures of the Amp case and inside.
These pics show the foam that I put in there to keep the parts inside the case from moving, it fills the space and keeps a good solid hold on the parts inside. The foam is cheap and easy to fit with the a razor blade.

The case through the non used voltage regulator circuit is grounded so that the connector outer shield is the minus side of the power supply (ground).
All that has to be done is connect the positive to the positive leads of the amps and the negative to the negative leads. I installed a 16V 10 MF capacitor across the power leads, this is a filter for the power supply.

The final part is caulking the the cables going into and out of the case. The caulk here is a non silicone base that will take paint.
I finished this process in 3 steps, the first step was to get the gaps around the cables filled in and let it dry.
The other two steps built up the caulk around the cables and created a type of soft strain relief. Put a layer on and let it dry the add another and let it dry.
To make an RGB system for GRB using these amps is easy. You will need two amps built and a "T" splitter with "F" connectors. You will split the RG-59 power cable to the two amp cases. There will be two cables for the RF side going to the computer and one power cable, making a total of 3 cables.
I would make sure that the 5V supply has at least 1 amp of better power output with this method.
There is no issue of cable impedance with the RG-59 as all it does is provide power for the amps.
One final little note: The 2' long LMR240 cables coming from the amp case is set up like this...
The input cable has a SMA male on it that mates to the connector on the feed. The output cable is a SMA female connector, that connects to the male SMA on the 120' of cable to the house.
This amp is currently working and running my GRB station, as of this writing I have found no issues with it and it works good. The final finishing step (as like the feed) is to paint it white.

 

[N6BY]

I haven't posted here in several weeks, but there have been some interesting developments:

1) Ed Murashie in California is receiving GRB at 9 dB SNR with a 6' dish, a can antenna and some home made amplifiers!
2) Ed has also made a single polarity patch feed which receives GRB. He is currently trying to build a dual polarity patch feed.
3) GRB Imager can now lock the signal automatically without the need to reset the coax! (which was a real P.I.T.A). It does this by rapidly changing the tuner gain setting. I figured that I could simulate a coax reset in my program and I was right. It works best if the signal is not amplified too much by LNAs.

I hope to duplicate Ed's patch feed and try it on my dish. Will post photos and construction info here if I am successful.

 

[GOES 12 GVAR user]

Some updates here as well,
Firstly, I got the storage drive for the files upgraded to a solid state drive. This has sped up the process of maintaining the data on the drive. This also helps access the data for viewing slideshows with the large images.
I also installed a simple but powerful file server on the machine that has GRB Imager on it. This server has the ability to be put out over the world wide web, for my use (at this time) it just does local network.
The program is free and called HFS.

Link to HFS

With Windows file sharing ability I can share the folder all the images are in so I can display the data on other machines. This is handy as most image viewers don't have the ability to go to a single URL and download the files (such as my server)
But they will work with the "my network" file system.
There is one drawback though, the large files such a the visible images for the meso sectors and the CONUS files (all) don't work well unless the image viewer has the actual files on the machine that it's loading them from. You can get away with the IR images in the meso sectors since they are smaller.
So far the best viewers for sideshow viewing I have found are:

Windows photo viewer: default image software for windows machines, this has the ability to make quick slide shows for the CONUS sectors and smaller. Runs pretty fast when you hold the arrow keys down for forward or backward.
Another little program does good slide shows is JPEGview, I got this program off of Sourceforge.net

link to JPEGview

This program works quite well and it (over the network) will load the new images in the directory that you are getting the images from.
Though again this works best if it has the actual files on the machine that the software is on.
You can zoom in on the image and maintain the view with locking the parameters. This program is 32 and 64 bit. Again the arrow keys work well for the scrolling through the frames, though the software has the ability to animate the frames it's self.
The final program I have found that works is Office picture manager. This program like JPEGview will allow you to zoom into the image and maintain the view through the frames. This program does seem to be more resource intensive compared to JEPGview. With all the examples of viewers I have not tried doing anything with the full disk images and I think that this could be a tough task for these programs due to the large size of the images.
The above listed programs are not by any means perfect but gives the user the options of putting the images in motion and examine the weather on a near real time basis.

 

[AB0CV]

Hi - I'm new to this site, but not to satellite imaging. I've been involved in amateur satellites and weather sats since the mid-80's, so I have a lot of experience. I have spent the last 10 years experimenting with hardware for the POES, however, I'm just now getting into the digital GOES, after years of WEFAX monitoring. I have a 6 ft dish with an Alfa-Spid Big RAS HR Az/El rotor, which I use for monitoring HRPT (AHRPT) etc. from the POES using home brewed helical feed, Low Noise Down Converter and receiver. I also have a 10 ft dish with a BIG RAS HR for monitoring GOES (I live in Missouri so I can get a good S/N from both GOES East & West). We moved recently, so I am in the process of getting all this hardware set up again. Could someone post or send me a link so I can download Brett's GRB Imager for Windows? Thanks. AB0CV

 

[primestar31]

Hi - I'm new to this site, but not to satellite imaging. I've been involved in amateur satellites and weather sats since the mid-80's, so I have a lot of experience. I have spent the last 10 years experimenting with hardware for the POES, however, I'm just now getting into the digital GOES, after years of WEFAX monitoring. I have a 6 ft dish with an Alfa-Spid Big RAS HR Az/El rotor, which I use for monitoring HRPT (AHRPT) etc. from the POES using home brewed helical feed, Low Noise Down Converter and receiver. I also have a 10 ft dish with a BIG RAS HR for monitoring GOES (I live in Missouri so I can get a good S/N from both GOES East & West). We moved recently, so I am in the process of getting all this hardware set up again. Could someone post or send me a link so I can download Brett's GRB Imager for Windows? Thanks. AB0CV

Brett is the N6BY guy up on post #657, just a few up. Click on his id, and "Start a Conversation" (PM) him directly.

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