Advice Needed Spectrum Analyser

manikm909

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is the point of a spectrum anaylyser to identify active TPs on any given satellite?
if so, why cant an STB have this functionality (i know theres a handful like the 5302 and some others) - and then once that initial "spectrum scan" has taken place, and the found TPs entered into the DB - cant they be scanned? INSTEAD of watiing for a full blindscan of a sat.
am i missing the point \ being a dimwit.
 

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What spectrum analyser have you acquired ?
 

manikm909

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i havent, just wondering what the point of them is...am i correct in what i asked? or am i way off?
 

ozumo

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A spectrum analyser shows the power of signals over a frequency range, rather than identifying the parameters of transponders. Can be used to indicate the presence of transponders or other radio signals, including interference, and show how strong they are.
 

moonbase

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i havent, just wondering what the point of them is...am i correct in what i asked? or am i way off?


A spectrum analyser can provide visibility of signals that are beyond the scope of a general satellite receiver and some PC software scanning tools.

A typical example is the Olympic Games NS4 mux currently uplinking to 10.0E on 12607 H.
EBS Pro and Crazy Scan using a TBS6983 card fail to lock the signal although CrazyScan does show it with an undefined presence.
A Dr HD F15 receiver also failed to "see" the signal let alone lock it and the F15 can "see" signals that are below a lock level.

The software based VMA simple spectrum analyser clearly shows the presence of the NS4 mux as would a standalone spectrum analyser.

.
20210721_10.0E_NS4_EBSPro.jpg 20210721_10.0E_NS4_CrazyScan.jpg 20210721_10.0E_NS4_VMA.jpg
 

s-band

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See the Turksat thread from here onwards for SA use Türksat-5a and new ku band??

You can use the info to set the frequency and take a guess at the SR to help the BS find things that are closely spaced and/or low SR.

<edit> almost forgot, peak the system on beacons

@moonbase What SDR are you using?
 

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AndyX

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I miss my DrHD receiver. It had n inbuilt spectrum analyser which was great for detecting new satellite position tests and feeds powering up. a great toy! Unfortunately, the inferred receptor died making remote control not possible.
 

Terryl

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@s-band

I am using one of those 138 MHz to 4.4 Ghz black box units that connects to the loop through port of a receiver with some type of DC blocker in line.
To look at the actual Ku band satellite transponders you would need a receiver or spectrum analyzer that can go to 12 GHz or more.(plus other stuff)

The receiver your using would only be able to look at the IF signals from the LNB, you would see all the down conversion byproducts and other junk.

I had a nice HP spectrum analyzer that went to 30 GHz, but it blew a CPU one day and HP wanted 4 grand to fix it.
 

s-band

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@moonbase I forgot about the VMA software. It does a fantastic job with low cost hardware.

@Terryl It's nice to use a pro grade analyser but the nature of sat TV is such that the dynamic range is quite small so simpler gear works just fine. I don't think that there's any need use the RF raw. For most people that's not practical anyway. I've never had trouble with spurii on Ku and Ka TV bands using the IF from LNBs. It's much more convenient to use the IF out on those bands. On 32GHz and Q band cable losses would be too great and long WG too expensive at RF. However, I do use direct RF into the analyser on some bands where I have LNAs at the dish and indoor down-converters.

Oh, even "pro-grade" analysers aren't spurious free.
 
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