Smallest EMWIN antenna

[usa-satcom]

Made a couple of changes to EMWIN decoder to enhance DSP and also faster lock. Here is short video of operation using 1.2m dish and non-optimal circular feed (should be linear for best SNR).

https://www.dropbox.com/s/zj36nppqlv4vpz5/enwim_airspy_sample.avi?dl=1

Joe

 

[GOES 12 GVAR user]

Anybody know of Mfgrs. that make the IF adapters for EMWIN (hardware version) besides Warner Labs, Zephyrus Electronics. Can't make the SDR software output the I/Q and will not upgrade OS (win XP) to use other software. Must go with a hardware version.

 

[usa-satcom]

Anybody know of Mfgrs. that make the IF adapters for EMWIN (hardware version) besides Warner Labs, Zephyrus Electronics. Can't make the SDR software output the I/Q and will not upgrade OS (win XP) to use other software. Must go with a hardware version.

Which SDR do you have ?

Joe

 

[GOES 12 GVAR user]

Hi Joe,
The SDR is the 100KHz-1.7GHz Full Band RTL-SDR USB Tuner Receiver R820T+2832U that can be bought of ebay for around 50 to 60 dollars.
The software I have been using is HDSDR.

 

[usa-satcom]

Hi Joe,
The SDR is the 100KHz-1.7GHz Full Band RTL-SDR USB Tuner Receiver R820T+2832U that can be bought of ebay for around 50 to 60 dollars.
The software I have been using is HDSDR.

Sounds good. I guess that sdr-console doesn't run on XP to well?

 

[usa-satcom]

Here are couple of images from GOES 15 via LRIT. Was doing some testing today with 1.2m dish. One is from Himawari-8 but is available via GOES-15 as additional product.

https://www.dropbox.com/s/pvrkef4mbm44zv1/hDK01_VIS_160405_0150c.jpg?dl=0

https://www.dropbox.com/s/yglx9lfyset6vcr/lGOES15_VS01_160404_2100.jpg?dl=0

Joe

 

[GOES 12 GVAR user]

Runs Windows 7 64-bit, Not recommended for XP. By what the website says.
Although the software runs on Core 2 Duo systems with 32-bit Windows XP.
Which I don't have.

 

[GOES 12 GVAR user]

Just finished testing this and here are some pictures and results. Compare these to the 1.2M offset dish. The results are better then I expected. I will get info up on how I made this antenna in a couple of days. It cost (less the electronics) about $115. This antenna can be made by anybody that has some creative skills and patience.
I call it the IMProveD Grid antenna.
Spectrum analyzer views and HDSDR screen shots.

Some antenna views. Aimed at GOES East

 

[doubleohwhatever]

Now that's what I call getting creative! It never occurred to me that the grid dish could be easily extended like that.

My 1.2m dish arrives tomorrow. We had some heavy rain tonight. So I'll probably get it assembled in the garage tomorrow and install it on Friday. I also ordered a LNA from down east microwave but it'll be at least a month before it arrives.

 

[GOES 12 GVAR user]

doubleohwhatever,
I know that you trying to get a better signal there. It's seeming that you may be in a high RF area that has a lot of intermod (garbage RF). I recommend use radio detection technique to make shure you have no RF very close or on the signal of interest. Since you have a downconverter and a LNA this is a simple task. Also since you're building the horn for the new dish this is a exellent time to do this.
To my knowing the LNA, Downconverter use somewhere around 12V DC to power. If this is the case a battery can be used to power the gear. All that would be needed is handheld radio that can tune to 139.2 Mhz and around that area. What you would do is put your LNA, Downconverter and battery in a bag, backpack or something you can strap to you without tying up your hands.
Tape them to the horn if you can't use a bag.
Connect everything together as is should be Horn/LNA/Downcoverter/Radio. Hold the horn in your hands (mouth outward from your chest) and make shure you radio is tuned to 139.2 Mhz or very near that as walk around your yard, your house. Listen for anything that the radio sounds on besides open white noise ( the squelch must be open allowing noise ). If anything comes on that radio that is clearly audible rotate your body aiming the horn in different directions and follow the signal ( staying in your yard ) observe what you are looking at and see if you can ID the source of the interference. Remember that you are listening on 1692.725 MHz so there
should be nothing there as this is a place defined for the WX satellites downlink in the RF spectrum. By doing this you may also find that your house electronics could be a source of some of that garbage. You can use an extension cord if you don't have a way to power the RF gear. If you don't have a handheld radio you don't need to buy one.

Think of the beam in this guys hand as the horn in yours, see what he is looking at...
Will be waiting to hear how your setup does.

 

[doubleohwhatever]

Almost finished with the feeds. I'm making one with an N connector and one with an SMA connector. I figure I might as well make one of each while I have the tools setup for it. I'll explore around the yard tomorrow or Saturday and see what kind of interference I find.

Unfortunately I got screwed on the dish via eBay. Attached is a photo of what I received. Definitely does not match the listing: www.ebay.com/itm/331627606646?_trksid=p2057872.m2749.l2649

 

[Titanium]

https://www.ebay.com/ulk/itm/120968126977

This is a much higher quality 1.2m dish. Heavier gauge reflector, better finish and hardware.

Most of us satellite hobbyists with 1.2M dishes either use a free used commercial Channel Master composite 1.2m type or the GEOSATpro 1.2.

 

[GOES 12 GVAR user]

Yep that's how I got mine Ti. A fellow ham saw it and asked if I wanted it, so after him hawing around I decided to get it. Some company several miles east of me was getting rid of it.
Got for free just had to haul away. The guy that saw it was so nice that he brought it to me.
doubleohwhatever did you contact the seller and tell him? is my first question.
It's not bad it will work but the focal lengths may be different then what I posted on here you will have the experiment with that depending what you do with it.

Ebay has a money back guarantee on that item if it isn't as described in the listing.

 

[catamount]

So, what's the difference about the dish? Is it just the mount? They sent you a j-pole mount and the pics show a ground mount. Contact the seller and tell them to send you a ground mount. Maybe they were out of stock on the ground mount? Otherwise file complaint as Goes 12 mentioned.

 

[doubleohwhatever]

did you contact the seller and tell him?

Yep. I haven't heard back yet.

So, what's the difference about the dish?

Completely different dish.

Contact the seller and tell them to send you a ground mount.

Not that simple. The mounting holes in the dish that I received won't accommodate the ground mount shown in the auction photos. They sent a completely different kit.

I can most likely make this dish work if they're willing to issue a partial refund or something. Otherwise this dish needs to go back.

 

[GOES 12 GVAR user]

ATTENTION ..... URGENT
I had a conversation with Bill Warner (owner of Warner Labs Inc ) yesterday and he has passed on very disturbing news.
Due to the national broadband plan proposed , The 1695 -1705 MHz band , FCC has auctioned off for Broadband use. This concerns us due to the new GOES R satellite's proposed HRIT transmission will be in this area that the FCC auctioned off so broadband nearby can and will likely cause interference to your ground station.
It gets worse, they (FCC) wants to auction off the rest of the GOES downlink frequencies in a few more years.
To find out more on this search: weather satellite bands auctioned off

As a webinar will be held April 14, Here is the message I got from NOAA:

A webinar on the EMWIN transition program will be held April 14, 2016 from 2 to 3 pm EDT to provide information on EMWIN service changes in 2016 and 2017. Information in the webinar will include the new HRIT/EMWIN broadcast on the GOES R satellite scheduled for launch in October 2016, and operational deployment in March 2017. There will also be information on EMWIN service changes that will take place during the same period.

Once registered, a VOIP phone number and PIN will be provided. I would ask that attendees develop questions ahead of time and type them in during the webinar, this will allow for a thorough written summary of the Q&A. The webinar will be recorded to facilitate accurate minutes and action items. The recording of the meeting will NOT be shared and is for internal use only.

Use the below link to register. If you have any other questions or concerns about the logistics of the webinar, please direct them to John Simensky @ john.simensky@noaa.gov.


https://attendee.gotowebinar.com/register/2511615884431815937


System requirements to view webinar link:
http://support.citrixonline.com/webinar/all_files/G2W010003

 

[GOES 12 GVAR user]

Quickie correction on frequencies 1695- 1730 Mhz.
Again search term: weather satellite bands auctioned off

 

[doubleohwhatever]

Well that is just utter cr@p. I know what I'll be doing next Thursday afternoon.

At first when you mentioned they were going to use it for broadband, I assumed/hoped that meant for point to point links. Apparently though, this slice of spectrum will be used by cell phones (section titled "Background"): http://www.nesdis.noaa.gov/OSGS/create.html

There's no way we'll be able to receive 1694.1 if cell towers are pumping out noise on 1695.

 

[doubleohwhatever]

By the way, I've discovered the source of my noise. I followed the instructions in the post above and found the direction the noise was coming from and then was dumbfounded when I looked at google earth. There's a well camouflaged cell site directly to my west. I've honestly never noticed it before. It looks very obvious in the photo I attached. However, from the ground it's really hard to see.

Jeez, if that things starts transmitting on 1695, I won't be able to receive antyhing.

 

[GOES 12 GVAR user]

doubleohwhatever,
Well you found the noise source. With a transmitter that close I can understand where you would be getting a higher noise floor and some of the harmonics. Ok doubleohwhatever now this is where you have to get creative.
When you were walking through and around by any chance did you find a quieter place in your yard that would work better for a receive location?
Is your siding on your house metal, or anything metallic?

Since you know where the noise is coming from you will have to try to shield the antenna from it. See the diagram.

You can use screen, a metal shed, anything that blocks the RF from that cell tower affecting your dish. This unfortunately makes it look more unpleasent, though I notice you have a fence around your yard so the only ones seeing it will be who lives there.
On the other note I'm going to recommend to NOAA that they leave the current EMWIN alone or just slightly widen the bandwith of the current data stream. At least this way the EMWIN signal will fit between the GRB and not the auctioned off spectrum. LRIT has a problem.
You should be good for a few years before public sector puts up transmitters on this band.
One last note, I recommend you contact your federal congress critters about this. Be clear and calm, explain to them what this means and why it's not good for the US. Wouldn't hurt to have them get in touch with NOAA's people and have a discussion about this.