Question about Ku Band LNBs

[Titanium]

Spaun, Sevis, Pico Macom, Tradewinds have inline f-fitting 22KHz tone generators powered by typical 13-18Vdc LNB voltage. Alibaba has similar devices listed (who knows the landed price at this time). I stocked the Spaun units. Don't recall the insertion loss, but they provided acceptable SNR headroom, as it was often required for receiving the target transponder frequency.

Powered satellite multi-switches provide both power and 22KHz on ports.

Leave a satellite meter inline. Many meters provide both power and 22KHz tone.

 

[arlo]

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!

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.

 

[holland-observatory]

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.

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

 

[arlo]

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

I was amazed and at the same time wondering what good drugs the Icom crew were doing when they offered the matching power supply for the R8600. I person would think that things like...the big thing...providing clean DC for a basically DC to daylight receiver would not be an issue. Especially a power supply that the only thing Icom is the sticker.
And at a premium price the 'matching' speaker with integrated power supply would be the same. The smps in those are the exact same thing but without the plastic enclosure.
I like working VLF. And lately a lot of VHF digital transmissions.
My ancient Collins, R8500. Just a length of wire brings in beacons, NAVTEX quite nicely. As long as you're away from noise sources. To do the same thing with the R8600 requires a battery supply. Loop antennas are next in the build queue.
Surprising too are lithium power sources. The BMS inside of them makes nasty noise and harmonics.
The difference using my bike and tractor batteries was almost disgusting.
On my bench I have a few fairly good lab power supplies. PWM. And recently got a linear lab supply.
Guys. If your current needs aren't real high. Go linear every day on the week. Okay or pc and digital stuff. For RF and audio. Linear power is just noise free.

I think you'll like the USB isolator. It's cool that you discovered ferrites. If the wall warts are super old, the filter caps in them might have or are failing. Nobody used Panasonic or Nichicon in them. I have boxes of them. A fairly large value cap and common mode choke on their outputs before your device never hurts.
Oh, and have fun.