Receiving signals from noaa weather satellites using malachite sdr

[dlwtrunked]

I'm betting if you re orient that whip, the signal is gone. These sats are just not that powerful.
It took a 15 Db gain preamp with my QFH to get some decent APT.
You need a good 25 Db signal to noise ratio for some good APT.
(Yea, overkill on the preamp, but attenuation makes up for it.)

I have always received them OK and based on the power and path expected that (I have just used a whip at times). 25 dB for decent APT would be be overkill here. However, with often fade due to less than an optimal antenna for sky coverage and polarity can be an issue and then gain like yours would then help. And of course that is particularly true for a discone. Not suere what yu are using for an antenna. I just (Sunday) sold and actually 137 APT antenna as it was too large/heavy for my rare use.

 

[dlwtrunked]

I have always received them OK and based on the power and path expected that (I have just used a whip at times). 25 dB for decent APT would be be overkill here. However, with often fade due to less than an optimal antenna for sky coverage and polarity can be an issue and then gain like yours would then help. And of course that is particularly true for a discone. Not suere what yu are using for an antenna. I just (Sunday) sold and actually 137 APT antenna as it was too large/heavy for my rare use.

While I was editing the above, I was interupted and editing timed out. Here is my edited version:
I have always received them "OK" and based on the power (5 W) and path expected that (I have just used a whip at times indoors). 25 dB for decent APT would certainly be overkill here. Grant it, it was not noiseless copy. (Although 5W seems small, for comparison, I also regularly copy weather balloons at 40 miles or so at less than 0.1 W which is very roughly a similar in strength effort.) However, with often fading due to less than an optimal antenna for sky coverage and polarity can be an issue and then gain like yours does help (if no overload by other nearby transmitters which I suspect can be a problem with a Baofeng as he has). Not sure what QFH design you had--mine was about 5 feet tall, 6 or 8 inch diameter and heavy. I just (Sunday) sold it as it was too large/heavy! (looked like a torpedo) for my rare use.
Generally though, of course, a Baofeng has too narrow a bandwidth for good copy to make added costs to improve it for APT and an SDR is by far the best way to go but he seems to have excluded that.

 

[ArloG]

I would think the concept (why a spinning antenna) and purpose cannot be put into simple terms is misleading. Come on, give it a go,
My QFH....Quadrifiler Helicoidal, Quadfifiler Helix....antenna in the attachment (stock and mine in the air) works very well in reception of apt satellites. But it doesn't "brick wall". I can receive wx radio, air traffic, public service. For RHCP 137 MHz transmissions it far surpasses a discone, v-dipole. Or a whip antenna.

The theory is simple. The technology is not so much. "Encourage" the received RF to come into the helical loops by making one loop "a little shorter" and the other "a bit longer" than the others. By how much? Enough to provide adequate bandwidth and tuned to the center frequency. And provide a quadrature shift in phase that is desired to attain circular polarization.
Very tolerant to horizon to horizon coverage. And a duplicate of the antenna on the satellite.
That wasn't so hard now. Was it?

When my dad was in the USAF I was fascinated with radiosonde launches. And how the ground station az/el tracker could track the l band transmitter. A spinning dipole at the feed point measured RF signal. The electronics package (all analog) sensed phased signal strength. And the servo driver package moved the dish.
AN/GMD-1. It was big, it was noisy. It shook. And it stunk like military mold killer.

Your spinning antenna. Are the elements cut for 137.5 MHz?
What does spinning them, as opposed to not, do? Come on. You can do it.
Yeah. Of course you're able to receive weather radio. The transmitter is probably putting out a mediocre wattage as opposed to.....5??...watts at how far away up in the sky?

Big bummer for years. My Icom IC-R8500 received 137 MHz sats. well. But with only a max FM bandwidth on 15 KHz.
Any image copied was disappointing. I tried FM wide (broadcast band). Signal was gone. SSB. Nope.
Before my IC-R8600. An SDR radio. My SDRPlay RSP2 FINALLY allowed me to get decent images.
Thanks to SDR software which would let me push the IF bandwidth to 30-40 KHZ needed. Success!

Your Putin Special. There are many flavors. You didn't state the model of it. If it IS capable of FM and 30-40 KHz bandwidth. At least.
Does it provide an FM discriminator output? Or just demodulated and filtered audio. Did I mention "SDR software"?

I assure you. I can record every satellite pass and process it all the live-long-day. With Doppler correction. And never hear a peep from the radio OR SDR software. And my antenna never spins.
'Splain me, Lucy. 'Splain me!

Why-do-you-use-an-"omnidirectional????"-antenna-for-non-line-of-sight-frequencies?

 

[chapi]

No disrespect, it is indeed a project in relativistic physics, trying to measure effects from distanced rf sources.
I’m doing many such an experiments, see for example:

But this is a radio forum and the question is still open: why can’t I receive the noaa’s signal on any of my 4 sdr radios while easily get it on the baofeng?

Merilin, the signal on the baofeng is very strong if you try it when the magnitude of the satellite signal is strong (5.8 and bellow, it shows on the ny2o site, highlighted in orange). I will try to take a video soon so everyone can see.

 

[chapi]

Anyone knows another good sdr radio except malachite?

 

[dlwtrunked]

No disrespect, it is indeed a project in relativistic physics, trying to measure effects from distanced rf sources.
I’m doing many such an experiments, see for example:

But this is a radio forum and the question is still open: why can’t I receive the noaa’s signal on any of my 4 sdr radios while easily get it on the baofeng?

Merilin, the signal on the baofeng is very strong if you try it when the magnitude of the satellite signal is strong (5.8 and bellow, it shows on the ny2o site, highlighted in orange). I will try to take a video soon so everyone can see.

Interested ion what the experiment is. Are you trying to see the time effects of earth's gravitiy? OR? If so you will need to GPS discipline your reciever clock. I do that on my radios that can. An Airspy and *some" SDR play can be GPS DO disciplined but those do not tune precisely so all you get with GPSDO'ing them is fantastic stability. I do not think a Baofeng is going to be anywhere good enough for such but an Airspy R2 with a Bodnar GPSDO *might* (I have not looked close) depending on the actual experiment.

 

[ArloG]

To me. The malakite is not a good sdr radio. It's bling. Nothing to be critical about.
The whole experiment seems to be taking the effects of RF phase shift into account.
The Dual GPS has a SkyTraq engine IC. Dead reckoning with accelerometer, gyroscope. And other bells and whistles.
So in essence it's not a "pure" GPS for GPS sake. Spinning it might be making it dizzy.

I know I had a buddy who got drunk once and put his kat in the washer on spin cycle. When the lid was opened, is staggered and stumbled around for a minute. Then bolted out the door never to be seen again. But. We were stupid kids and I had no part of it.

Since the GPS is used in aircraft. I'm pretty sure the firmware writers didn't take flat spin and corkscrew into the dirt into account.
By that time, it's time for a parachute and a new pair of pants.
Engineered for stunt and irresponsible flying? Or The Fast and Furious. Skeptical.

I would still like to find an Arduino or pi project for a satellite tracker that is autonomous. No GPS, No TLE. That tracks satellites based on RF signal and phase. No quantum mahambajamba.

Guessing that is why pilots still rely on ball compass', pitot tubes, seat-o-pants and common sense flying.
I mean. There are always good drugs in programmers realm. Ax me how I know! And Dual surely is not doing their own programming.
Johnny Woo and Kim Kim most probably in Shenzhen, I would vote on
Dual is now just a name. I have 3 Dual turntables from good old Germany when quality meant something. The test of time.
Unrelated to China who now owns the name. You can still obtain a Dual turntable from craftsmen who care.

It's an SDR world now. There are tons of good, great, and not so great receivers out there. Hands on reviews and your budget.
Take the plunge and get an IC-R8600. The -04 version. Buy once, cry once!
By the time a spinning GPS says negative altitude and you happen to be in an aircraft.
Pretty sure you and the XYL will be meeting a guy named Pete at some very nice gates. Don't take the kat with you, please.

 

[dlwtrunked]

Anyone knows another good sdr radio except malachite?

For HF, the only I find acceptable as good SDR radios are AirSpy R2 and SDRPlay (in that order), between $150 and $200, and a PC/labtop but they require a PC/laptop.
You need to be clearer, are you ruling out a PC. And if what you are doing requires very stable frequency (requiring a GPSDO) those are at your starting price (the R2 will take a 10 MHz $200 GPDSO signal but only some SDRPlay can. The cheapest way to do why I think you really want/needyou want is an AirSpy R2 with a $200 Bodnar at around $300-$400. Some one mentioned the ICOM R8600, I also have one, but you will also need to GPS discipline it for another $200 to do what I think you want.
And as I mentioned before, GPSDO on some radios means they are stabilized but the reported frequency may still have a hidden offset that the manufacturer often does not mention. IF you go cheap, I think you are likely doomed to fail if I understand (not clearly though) what you are trying to do.

As someone else said, the Malakite, is not a good radio at all for what you need (I had two, through one in the trash and gave another away). Nor is anyone like that a good radio (they must never have had a good radio to compare).

 

[chapi]

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As can be seen in the video, good reception of NOAA 15's 137.2 Mhz signal with the baofeng, No reception with the Malachit DSR radio.

 

[dlwtrunked]

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As can be seen in the video, good reception of NOAA 15's 137.2 Mhz signal with the baofeng, No reception with the Malachit DSR radio.

I hope you noted that you are tuned 5 kHz high on the Malachit; does the Malachie allow 5 kHz instead of 25 kHz steps? Not sure how much difference that made. I do not have its detailed specifications but 5 NFM is too narrow for good APT receiving. But overall, I just thing Malachite are terrible receivers.

 

[VK3RX]

I have the same Malahit model. Looking at your video it seems you have the 50 Ohm antenna socket set up incorrectly.

Showing "50 Ohm" in red on screen, according to the manual page 6:

50 OHM: The green light indicates that the Hi-Z antenna enabled and the red light indicates that the antenna power supply "(bias tee") is enabled indicates it has been set.

Go into the "Radio" menu and tap "PWR ANT" so it reads "disabled".

With the telescopic antenna or discone etc. connected to the 50 Ohm socket, that screen indication should be unlit (and the LED next to the antenna socket should be green).

See my pix below, with the telescopic antenna connected.

 

[merlin]

I hope you noted that you are tuned 5 kHz high on the Malachit; does the Malachie allow 5 kHz instead of 25 kHz steps? Not sure how much difference that made. I do not have its detailed specifications but 5 NFM is too narrow for good APT receiving. But overall, I just thing Malachite are terrible receivers.

Correct me if I am wrong, but the tune steps on the Malahit, can go down to 10 Hz (maybe 100 Hz)
For good APT decode the bandwidth has to be 30 KHz with the signal centered. there usually is an offset based on doppler shift.

 

[chapi]

To me. The malakite is not a good sdr radio. It's bling. Nothing to be critical about.
The whole experiment seems to be taking the effects of RF phase shift into account.
The Dual GPS has a SkyTraq engine IC. Dead reckoning with accelerometer, gyroscope. And other bells and whistles.
So in essence it's not a "pure" GPS for GPS sake. Spinning it might be making it dizzy.

I know I had a buddy who got drunk once and put his kat in the washer on spin cycle. When the lid was opened, is staggered and stumbled around for a minute. Then bolted out the door never to be seen again. But. We were stupid kids and I had no part of it.

Since the GPS is used in aircraft. I'm pretty sure the firmware writers didn't take flat spin and corkscrew into the dirt into account.
By that time, it's time for a parachute and a new pair of pants.
Engineered for stunt and irresponsible flying? Or The Fast and Furious. Skeptical.

I would still like to find an Arduino or pi project for a satellite tracker that is autonomous. No GPS, No TLE. That tracks satellites based on RF signal and phase. No quantum mahambajamba.

Guessing that is why pilots still rely on ball compass', pitot tubes, seat-o-pants and common sense flying.
I mean. There are always good drugs in programmers realm. Ax me how I know! And Dual surely is not doing their own programming.
Johnny Woo and Kim Kim most probably in Shenzhen, I would vote on
Dual is now just a name. I have 3 Dual turntables from good old Germany when quality meant something. The test of time.
Unrelated to China who now owns the name. You can still obtain a Dual turntable from craftsmen who care.

It's an SDR world now. There are tons of good, great, and not so great receivers out there. Hands on reviews and your budget.
Take the plunge and get an IC-R8600. The -04 version. Buy once, cry once!
By the time a spinning GPS says negative altitude and you happen to be in an aircraft.
Pretty sure you and the XYL will be meeting a guy named Pete at some very nice gates. Don't take the kat with you, please.

 

[chapi]

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As can be seen in the video, it’s possible to eliminate the audio from the weather channel by changing the receiving mode from fm to lsb

 

[chapi]

VK3RX, Thanks. I'll check it up and try it at the next NOAA's passing.​

If you are right and it will solve the problem, This thread is precious

That's what this forum is for!

 

[MUTNAV]

This may sound like a silly idea given all of the Quantum and science stuff being discussed, but there is a degree of Doppler shift in the LEO satellites.

Is your SDR in SSB mode centered on what the doppler shift should be at each moment in time ?

The traditional way of DFing satellite things is to listen for the tone shift from high to low as it passes. Doesn't have to be by ear, electronically is fine.

Thanks
Joel

 

[VK3RX]

Just caught a pass here by NOAA 19 on 137.100

27° elevation and antenna is only a discone, used NFM because barely audible on WFM.

As others have said you really need a receiver with 30kHz bandwidth, and preferably also a masthead preamp.

 

[chapi]

Mutnav, why will the Doppler affect the malachite sdr but not the $30 baofeng?

 

[MUTNAV]

Mutnav, why will the Doppler effect the malachite sdr but not the $30 baofeng?

Like I had suggested, maybe a wider bandwidth? I know on Ham satellites, people need to adjust their uplink and downlink frequency as the satellite changes position.

Can you receive the NOAA bird with the malachite sdr in FM mode, with the bandwidth set the same as the baofend?

If not, it could be a different problem (antennas/connections, settings, etc...)

I know somewhere between little and nothing on this subject, but I did notice a lack of dealing with the apparent frequency changes from Doppler effect.

Thanks
Joel

 

[chapi]

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Another pass of noaa 15, good reception with the baofeng, 0 with the malahit.

Can someone check the settings to see if it’s correct?

Also, is there any geostationary satellite which is possible to get reception from in the 100-500 mhz range?

Thanks.