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arlo said:

Haven't seen mention of the Othernet Bullseye lnbf. Seems to be the ku band lnbf choice of many moonbounce fans.
Surprised you haven't heard of it. I thought it was cool that when Othernet was up that you didn't even need a dish.
Anyway. Lot's of geekiness here:

Bullseye

Click to expand...

arlo said:

On a component level. From a few lnbf teardowns. Trying to look up datasheets for the individual IC's can be a crap shoot. Some have a gasfet, etc., transistor hoked to the antenna probes in the throat before the mixer IC. And some feed the H & V probes either into a switching circuit then into an all-in-one IC.

Looking for the best-of-the-best in off the shelf components for your hobby for the highest gain and lowest noise might even have you doing exactly what you are doing. Experiment with different stuff.
Why did my Titanium C2-W let considerable circular polarized signals come in and my orthomode does not without using a depolarizer? Better yet. When I get a light dusting of snow on the lower half of my dish. Circular transponders come in a few dB more? Ain't microwaves fun?

A couple of thoughts. When c band started showing up and there were tons of manufacturers, installers capitalizing on the home user business. We separate had LNA's and downconverters attached either with Type N to N couplers, short chunks of coax.
And the LNA's were rated by degrees Kelvin. LNA's were built basically by hand picking the active and passive components. A 22K LNA and 11K could be built on the same bench. Measure the specs and sticker it accordingly. Relate to the trusty old CK 722 transistor. I believe that I read when transistorized hearing aids came out. The CK 722 were actually the ones that didn't make the cut. mmm.....What WERE the originals that did?

Sometimes I get freaky and hard to find noisy components. Bad solder pads. Stuff. Hot air and freeze spray? Priceless. And Germanium transistors, transistors that have gone "black lead"...hissy diodes. Cripes!
Freeze spray. Lower the Kelvin temperature. Cool down the atomic noise. Like the DSN does by chilling the feed components. I looked. There are in fact cryo cooled LNA and feed components for the big boys.
What if....just if. You packed a bag of dry ice around your lnb? Or gave it a good shot of a CO2 fire extinguisher while looking at your signal stats?

...i may be out there but i ain't THAT far out.

Click to expand...

arlo said:

On a component level. From a few lnbf teardowns. Trying to look up datasheets for the individual IC's can be a crap shoot. Some have a gasfet, etc., transistor hoked to the antenna probes in the throat before the mixer IC. And some feed the H & V probes either into a switching circuit then into an all-in-one IC.

Looking for the best-of-the-best in off the shelf components for your hobby for the highest gain and lowest noise might even have you doing exactly what you are doing. Experiment with different stuff.
Why did my Titanium C2-W let considerable circular polarized signals come in and my orthomode does not without using a depolarizer? Better yet. When I get a light dusting of snow on the lower half of my dish. Circular transponders come in a few dB more? Ain't microwaves fun?

A couple of thoughts. When c band started showing up and there were tons of manufacturers, installers capitalizing on the home user business. We separate had LNA's and downconverters attached either with Type N to N couplers, short chunks of coax.
And the LNA's were rated by degrees Kelvin. LNA's were built basically by hand picking the active and passive components. A 22K LNA and 11K could be built on the same bench. Measure the specs and sticker it accordingly. Relate to the trusty old CK 722 transistor. I believe that I read when transistorized hearing aids came out. The CK 722 were actually the ones that didn't make the cut. mmm.....What WERE the originals that did?

Sometimes I get freaky and hard to find noisy components. Bad solder pads. Stuff. Hot air and freeze spray? Priceless. And Germanium transistors, transistors that have gone "black lead"...hissy diodes. Cripes!
Freeze spray. Lower the Kelvin temperature. Cool down the atomic noise. Like the DSN does by chilling the feed components. I looked. There are in fact cryo cooled LNA and feed components for the big boys.
What if....just if. You packed a bag of dry ice around your lnb? Or gave it a good shot of a CO2 fire extinguisher while looking at your signal stats?

...i may be out there but i ain't THAT far out.

Click to expand...

arlo said:

On a component level. From a few lnbf teardowns. Trying to look up datasheets for the individual IC's can be a crap shoot. Some have a gasfet, etc., transistor hoked to the antenna probes in the throat before the mixer IC. And some feed the H & V probes either into a switching circuit then into an all-in-one IC.

Looking for the best-of-the-best in off the shelf components for your hobby for the highest gain and lowest noise might even have you doing exactly what you are doing. Experiment with different stuff.
Why did my Titanium C2-W let considerable circular polarized signals come in and my orthomode does not without using a depolarizer? Better yet. When I get a light dusting of snow on the lower half of my dish. Circular transponders come in a few dB more? Ain't microwaves fun?

A couple of thoughts. When c band started showing up and there were tons of manufacturers, installers capitalizing on the home user business. We separate had LNA's and downconverters attached either with Type N to N couplers, short chunks of coax.
And the LNA's were rated by degrees Kelvin. LNA's were built basically by hand picking the active and passive components. A 22K LNA and 11K could be built on the same bench. Measure the specs and sticker it accordingly. Relate to the trusty old CK 722 transistor. I believe that I read when transistorized hearing aids came out. The CK 722 were actually the ones that didn't make the cut. mmm.....What WERE the originals that did?

Sometimes I get freaky and hard to find noisy components. Bad solder pads. Stuff. Hot air and freeze spray? Priceless. And Germanium transistors, transistors that have gone "black lead"...hissy diodes. Cripes!
Freeze spray. Lower the Kelvin temperature. Cool down the atomic noise. Like the DSN does by chilling the feed components. I looked. There are in fact cryo cooled LNA and feed components for the big boys.
What if....just if. You packed a bag of dry ice around your lnb? Or gave it a good shot of a CO2 fire extinguisher while looking at your signal stats?

...i may be out there but i ain't THAT far out.

Click to expand...

arlo said:

Haven't seen mention of the Othernet Bullseye lnbf. Seems to be the ku band lnbf choice of many moonbounce fans.
Surprised you haven't heard of it. I thought it was cool that when Othernet was up that you didn't even need a dish.
Anyway. Lot's of geekiness here:

Bullseye

Click to expand...

holland-observatory said:

But, I could not find a place to buy one.

Click to expand...

QO-100 Bullseye TCXO LNB - Ultra Stable for Ku Band Satellites 10489 - 12750 MHz | eBay

Under normal outdoor conditions, the stability of the LNB is well within 10 kHz of offset. As a bonus feature, the Bullseye 10K provides access to its internal 25 MHz TCXO through the secondary (red) F-type connector.

www.ebay.com

primestar31 said:

QO-100 Bullseye TCXO LNB - Ultra Stable for Ku Band Satellites 10489 - 12750 MHz | eBay

Under normal outdoor conditions, the stability of the LNB is well within 10 kHz of offset. As a bonus feature, the Bullseye 10K provides access to its internal 25 MHz TCXO through the secondary (red) F-type connector.

www.ebay.com

Click to expand...

holland-observatory said:

Excellent! Thanks - just ordered one.

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holland-observatory said:

For some reason, I cannot reply to your posts. I keep getting an error.

Thank you for the input. I have been cooling my SDR to keep it cool and regulate its temperature. I have thought about cooling the LNAs and LNBs too. Thanks!

Thank you for the input. I have been cooling my SDR to reduce the noise and regulate its temperature. I have thought about doing the same for the LNAs and LNBs too. Thanks!

Click to expand...

arlo said:

The reply thing, dunno. A link that shows a bit of geekery and just plain time on your hands and wondering 'what if??' :

Cooling the LNB

Something to note is that the Bullseye has a TCXO. So chilling the unit below (or heating it) above the rated specs could give a bit of frequency drift and stability issues. I think. Who knows! Common sense.
I mean. Hacking IN a freq. reference could be an option. It has the 25 MHz reference output.
I think here deep in the archives are snippets telling of doing the same. HAM equipment often has an input for a 10 MHz master oscillator. GPS, Rubidium reference source. If that's even important.

And this is just an FYI found out when jumping into the SDR world.
First and formost if you're looking for the most "quiet" environment possible.
GET RID of EVERY smps power supply within a hundred miles.
Buy ferrite bead USB cables. I use genuine Tripp Lite cables exclusive ly.
Buy a bag of snap-on ferrite chokes. Use them.
Case in point. I first got an SDRPlay RSP 2 in the metal (not plastic) enclosure. Using my laptop. Fun but with a learning curve.
Later on I purchased an Icom IC-R8600. It is in essence an SDR receiver with knobs.
Throughout the lower ham bands and down into VLF the noise floor using the radio in SDR mode was crazy nuts.
I first noticed after awhile that simply touching the USB shell to my laptop before actually plugging it in made for some serious hash. BTW, the Asus laptop battery was at the end of its life and unplugging it from the power adapter gave just a few minutes of runtime. Remember that.
paragraph time..lol!

Why the noise? Where is it coming from? Even not hooked up to the laptop, the noise floor sucked.
You'd never notice with the SDRPlay because it was 100% computer dependent to make it work. Right?
My old IC-R8500 was quiet. It uses a linear power supply. My boat anchors? Toss a piece of wire out the window for an antenna and they are happy.
The R8600? SMPS. Icom, why? Ideas.....
I yanked the lithium battery from my Harley that made it start like a lightning bolt came down out of the sky.
Fashioned up a DC cable. Hooked the Icom up to it. Qui-et! Man oh man was it quiet. But still not as quiet as the R8500 on it's linear supply. But a huge improvement.
More ideas. Lithium batteries and BMS circuits. And they have PWM chips internal to regulate charging, discharge, output voltage and current regulation.
Yanked the flooded lead acid battery from the Kubota. Did the same. Provided pure DC to the radio and holy crap!
Quiet.
paragraph? nah....not 'chet.
Speed this up. NO SMPS NOTHING.
Laptop makes PWM RF noise. You can reduce it. Make sure the battery can hold a charge so the BMS isn't trying to run full blast charging a done battery. Laptop power supply is a source of PWM noise.
Laptop plugged in, USB to SDR.....noisy. Good and fully charged laptop battery. Lots less noise.
A good filtered or even linear power supply on the laptop helps.
CYD made the factory laptop supply. I needed a new one. The one I got also happened to be made by them.
More noisy than the OEM. Split it open. Less output filtering inductors and capacitors that factory. CYD direct sent a replacement. Same thing. Ferrite beads. Use them.
now it's time

Lastly. USB noise. What really worked to lessen SDR to PC USB noise? A USB isolator. Basically a fancy optoisolator that plugs in-between devices. PWM cannot jump across light. And so far that's what I stand with. A few bucks investment.
And I would figure out how to power that LNBF with pure DC. As much as you can. A good oscilloscope really is nice for crap like this. Not one of those Fin-Rizzy ones. A man's 'scope.

Anyways. Have fun. This would have gone better over a few pints of Sammy Adams Lager.

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holland-observatory said:

Thank you for the great information! I actually have experienced some of the things you mentioned. I do have a nice (and large) set of snap on ferrite beads and have had good success with them. I have experienced a lot of issues with USB cables causing interference like you said. I have not thought of the optical isolator, but that is a really good idea. The best success I have had is by using the shortest USB cable I could find, about 3" long with ferrites installed. I do also use linear only power supplies especially on my Low Noise Amplifiers (LNA). I am using basically my old transformer based wall warts from the 1970s and then stepped down at the LNAs by a low noise linear regulator that I designed and built. Thanks for listing your experiences. It is always good to hear what successes others have had.
Thanks,
Doug

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