Архив за 02.09.2019

GOES-16 Reception Issues

So, I've been working on receiving GOES images for at least a month now and I've hit a wall.

I'm using the NooElec GOES+ Sawbird, plugged directly into a NooElec NESDR SMArTee XTR SDR.

My dish is a 2.4 GHz 24 dBi Die Cast Mini-Reflector Grid Antenna with the 1-inch PVC spacer mod.

I'm able to point the dish correctly, however no matter what adjustments I make, I can't get the vit below 800.

I can clearly see the signal in SDR# but most of the time goesrecv can't see a thing.

Any suggestions as to what I could be doing wrong? Thanks all.

submitted by /u/grenvaltruvaki
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Any way to make animations from NOAA iamges?

Hey I had taken some images from NOAA the last few days and was looking for methods to align those images correctly for making an animation. The map overlays need to be matched and I am finding that very difficult to do on photoshop. Is there any way this can be done on wxtoimg or any other platform using the map files or any other thing?Here are the images I want to align:

submitted by /u/puneet_shrivas
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Any clue what this could be? The signal off center to the right looks like POCSAG, but I couldn’t get anything from it.

Any clue what this could be? The signal off center to the right looks like POCSAG, but I couldn't get anything from it. submitted by /u/ColTaylon
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KerberosSDR • Re: Sources for antennas?

The are good and I got mine from Ebay and other Source.

Statistics: Posted by Username — Mon Sep 02, 2019 8:54 pm

KerberosSDR • Re: Sources for antennas?

Thanks.....I realize there are many websites that sell antennas.

Statistics: Posted by 253flo — Mon Sep 02, 2019 8:49 pm

Comment on Reviews of the NanoVNA: An Ultra Low Cost $50 Vector Network Analyzer by Nebojsa Kovacevic

No problem. Leave info for private messaging…email or so.

KerberosSDR • Re: Sources for antennas?


Statistics: Posted by Username — Mon Sep 02, 2019 7:39 pm

KerberosSDR • Re: Sources for antennas?

Username wrote:
Mon Sep 02, 2019 5:49 pm
I mean freq?
Voice comms (encrypted and unencrypted) in the VHF and UHF spectrum is where I'd like to start. I know providing a specific freq would be better but I'm just not there yet.

Statistics: Posted by 253flo — Mon Sep 02, 2019 6:15 pm

KerberosSDR • Re: Sources for antennas?

I mean freq?

Statistics: Posted by Username — Mon Sep 02, 2019 5:49 pm

Antennas • antenna resistive loss vs. diameter vs. bandwidth (capacitance)

I assume I understand what you are asking now.

You are asking about the effect of conductor diameter onto bandwidth and antenna efficiency. Those are all related to antenna efficiency and bandwith but different effects are involved. It is always a tradeoff what is sensible to do for a given frequency, and in consequence if you get an improvement and how much it improves operation.

These effects are

1. The resistance of conductor reduces the antenna efficiency. Silver being the best but also most expensive conductor, than cooper, aluminum and steel.

2. The so called skin effect, describes that the higher the frequency is, an increasingly thinner diameter of the outer surface a wire conductor is used for RF. Therefore at higher frequencies you don’t need a solid conductor any more and tubing is sufficient.
To improve conductivity often a thin silver coating on a cooper basis e.g. inductor coils or pcb, only have the outer surface is coated by silver to improve conductivity/reduce resistance. When a gold plating is applied e.g. coax connectors instead of silver, the reason is to eliminate corrosssion.
The exception of this is the use of threaded wires, e.g.those coils wound around ferrite antennas for AM (<1700 kHz) and lower frequencies.
For Skin effect see https://en.wikipedia.org/wiki/Skin_effect

3. The thicker the wire/surfaces of tubing is, the more the antennas capacity and in consequence bandwidth can be increased within limits.

As said before, you can only achieve a compromise and it depends on the frequency which material and diameter of the conductor gives you the best performance and bandwidth.
keep getting some "ghost signals" I call them. Just to one side of a signal, is like a slightly smaller power image of the same signal sometimes.
Can you provide sreen shot how the signal looks like? I assume you have here some not antenna related effects.

Statistics: Posted by snn47 — Mon Sep 02, 2019 5:42 pm

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