Not very successfull with SDR - Advice

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Re: Not very successfull with SDR - Advice

Post by Username » Wed Jun 21, 2017 1:25 pm

So dont argue arround and get an LNA from Ebay or Amazon and you will receive anything above 30mhz. :evil:
If you have some money left get an good SDR Dongle to! :roll:
When you not know what you have to buy tell me and I give you some link.

hotpaw2
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Re: Not very successfull with SDR - Advice

Post by hotpaw2 » Wed Jun 21, 2017 6:25 pm

An LNA won't help if the reason for lack of success is due to a high RF noise floor. An LNA (without an appropriate bandpass or notch filter) amplifies the noise just as much as the signal, so would be no help whatsoever if the problem is RF noise at the antenna.

One solution might be to use, not an LNA, but pre-selector or bandpass filter, and a perhaps a directional antenna. The Ham-it-up might actually be attenuating the signal a bit or even adding noise (USB power supply), so you might want to remove it and re-test. The computer itself may be an RF noise source, so you might want to try putting the RTL-SDR at the far end of a long USB extension cable, away from any other electronics.

Username
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Re: Not very successfull with SDR - Advice

Post by Username » Wed Jun 21, 2017 6:48 pm

omg again ok?
The Upconverter work just to 30mhz. evrythink above require an LNA.
He config sdr# total wrong. When he do what I tell him it will work.

darrenyorston
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Re: Not very successfull with SDR - Advice

Post by darrenyorston » Thu Jun 22, 2017 12:23 am

This isnt productive.

According to NooElec the SDR doesnt require an LNA. Without the HamItUp the dongle, according to NooElec, should be able to receive from 25MHz to 1750MHz. At the moment the only traffic I can receive is in the commercial FM block between say 88.5MHz and 105.7MHz.

I have tried three antenna; my D-130 Discone, standard housegold roofmount TV/radio antenna and the short stubby antenna which came with the SDR. Same response across all three antenna, FM only.

I need to determine whether SDR# is configure correctly. I though I had followed examples I have seen on YouTube however have been unsuccessful.

According to NooElec's guide the only thing I need to do to utilise the upconverter is:

"Before operating your unit for the first time, and every time you run with a new SDR, we recommend running the tuning procedure located here. It is not a mandatory procedure but may help fine-tune your, erm. tuning. The basic operational instructions follow.

Connect your antenna to the RF input
Connect your SDR to the IF output
Ensure your toggle switch is in the enable position
Plug your USB power source into the USB-B USB jack
Fire up your favorite SDR software. Tune to 125MHz + (+/- the tuning offset from the tuning procedure) + your desired frequency and enjoy!"

So where else would I look on SDR# to ensure I have it configured correctly?

rtlsdrblog
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Re: Not very successfull with SDR - Advice

Post by rtlsdrblog » Thu Jun 22, 2017 4:41 am

If you're tuning to 125 MHz for HF with the upconverter enabled, then make sure that SHIFT is set to zero.

Your discone, tv antenna and short stubby antenna aren't really good for HF. Infact the TV antenna and short antenna are probably 100% useless for HF. A roof mounted D-130 might get something on broadcast AM frequencies, but probably not much else. If you have a very noisy environment it might not get anything. Try a 5 meter+ long wire instead, strung up over your roof.

Have you got a more recent screenshot with the correct frequency and SHIFT set? Tune to 126 - 127 MHz (1-2 MHz) where broadcast AM lives, and set SHIFT to zero. Alternatively, set SHIFT to -125,000,000 and tune to 1-2 MHz.

Also show us your RF gain settings in the screenshot (the control box that you get after clicking on the cog icon in SDR#)

Username
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Re: Not very successfull with SDR - Advice

Post by Username » Thu Jun 22, 2017 4:36 pm

If you're tuning to 125 MHz for HF with the upconverter enabled, then make sure that SHIFT is set to zero.
Again?
http://www.nooelec.com/store/ham-it-up.html
Look an the diagram:
Image

So what did you see? There are 2 Path for the Signal:
1) who is 1:1 passing trout without any Signal Procession or Ampilfieng.
2) at the first think there is a filter the "x" will be a mixer and than come the LNA.

So what the Diagram say its it not possible to receive with the Device anything above 30mhz?!
Have you got a more recent screenshot with the correct frequency and SHIFT set? Tune to 126 - 127 MHz (1-2 MHz) where broadcast AM lives, and set SHIFT to zero. Alternatively, set SHIFT to -125,000,000 and tune to 1-2 MHz.
It will not work becose the upconverter filter aythink above 30? Mhz!
Without the HamItUp the dongle, according to NooElec, should be able to receive from 25MHz to 1750MHz. At the moment the only traffic I can receive is in the commercial FM block between say 88.5MHz and 105.7MHz.
The Dongle is DEB!!!!! You can receive just Radio becouse the Send out with an HUGE Output power!!!!!!
I need to determine whether SDR# is configure correctly.
Is this a madhouse?!
Again do you want do what I say to get anything with our SDR YES OR NO?!

hotpaw2
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Re: Not very successfull with SDR - Advice

Post by hotpaw2 » Fri Jun 23, 2017 9:51 am

If you haven't already, you might want to remove the Ham-it-up converter so you can debug each component (converter versus RTL-SDR) separately. After removing the converter, set the offset in your software to zero.

I'm using a discone on a long coax, with no LNA, and can receive local aviation band AM and marine band FM signals, no problem. If you can't, some possibilities are that you have a partially dead (deaf) RTL-SDR stick, or that there is very strong RF interference in your neighborhood that is swamping any weaker signals. If you are near a broadcast AM or FM station, that can do that, since your RTL-SDR has no pre-filtering. If you have a laptop, you can try testing the RTL-SDR on a trip out of town to see if your neighborhood is causing the problem.

The up-converter (used with an offset enabled) is really only good for enabling receiving RF spectrum well below 50 MHz or so (broadcast AM, amateur HF, and shortwave, etc.) with an antenna bigger than a discone.

rtlsdrblog
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Re: Not very successfull with SDR - Advice

Post by rtlsdrblog » Fri Jun 23, 2017 10:57 am

When the upconverter is switched ON its mixer is active. So all HF signals will be mixed UP to 125 MHz. Hence you tune to 125 MHz to receive the HF signal.

Here's the explanation of the diagram that you posted: The 0-30 MHz HF signal comes in, is filtered to remove anything above 30 MHz via the LPF, is then mixed UP to 125 MHz, and then a bandpass filter is used to remove any mixer aliases. So now 0 MHz is at 125 MHz and 30 MHz is at 155 MHz.

Again, an LNA is NOT required for most people. The NF of the dongles is not that bad, though it's average. An LNA can certainly help improve SNR though, especially for UHF and L-band. It will help with cable loss and reducing the system NF.

P-40 Warhawk
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Re: Not very successfull with SDR - Advice

Post by P-40 Warhawk » Tue Jun 27, 2017 2:22 pm

I don't know if anyone knows that a lot of disk cone antenna don't have the right connector on them and your problem could be that you have a antenna with the wrong connector on it . A disk cone antenna that is rated at 25 mhz to 1300 mhz should have a female N connector on it . Here is what Amphenol has to say about N connectors . Electrical
Impedance 50 Ohm
Frequency Range 0-11 GHz
VSWR
M30912 Straight Connectors 0-11 GHz 1.30 Max
M30912 Right Angle Connectors 0-11 GHz 1.35 Max
Dielectric Withstanding Voltage 2500 VRMS
Voltage Rating 1500 volts peak
Insulation Resistance 5000 MΩ min
Contact Resistance
Outer Contact 0.2 mΩ
RF Leakage -90 dB min @ 3 GHz
Insertion Loss 0.15 dB max @ 10 GHz

Environmental
Temperature Range:
TFE Insulation -65⁰C to +165⁰C
Copolymer of Styrene -55⁰C to 85⁰C
Weatherproof All series N with gaskets are weatherproof
Hermetic Seals Pass helium leak test of 2 x 10-8 cc/sec
Pressurized Shock Compressed seal Mil-STD-202, Method 213
Vibration Mil-STD-202, Method 204 (test cond. D)
Moisture Resistance MIL-STD-202 Method 106
Corrosion Mil-STD-202, Method 101 ( test cond. B)
Temperature Cycling Mil-STD-202, Method 102 (test cond. D)
Altitude MIL-STD-202 Method 105 (test cond. C)

Mechanical
Mating 5/8-24 threaded coupling
Cable Affixment (Braid or Jacket):
All Crimps Hex braid crimp
Clamps Screw-thread nut and braid clamp
Cable Affixment (Center Conductor):
Crimps Crimp or solder
All Others Solder only
Captivated Contact:
All Crimps Yes
Others Where specified
Cable Retention
Crimps 60-120 lbs
Clamps 30-70 lbs

To many disk cone antennas are sold with SO-239 connectors on them say that they are 25 mhz to 1300 mhz but they are not , the connector is only good to 300 mhz . Here is what Amphenol has to say about that connector .

Description of SO-239 connector
UHF - Invented in the 1930’s by an Amphenol
engineer, E. Clark Quackenbush, for use in the
radio industry.
UHF coaxial connectors are general purpose
units developed for use in low frequency systems
from 0.6 to 300 MHz.
UHF is an acronym for “Ultra High Frequency”.
When the UHF was introduced, 300 MHz was
considered High Frequency.
The coupling on a UHF is threaded.
Since UHF connectors are low cost, the impedance
is variable.
Features/Benefits
• Optional reducing adapters accommodates a
wide range of popular coaxial cables.
• Solder termination types require no special
assembly tools.
• Crimp termination type connector available
provides a lower cost installation method.
• Large size threaded coupling - rugged design.
• Non-demanding specifications and low cost.
Applications
• Antennas
• Cable Assemblies
• CB Radios
• Low Frequency Applications
• Public Address Systems

rtlsdrblog
Site Admin
Posts: 2784
Joined: Mon Nov 19, 2012 11:54 pm

Re: Not very successfull with SDR - Advice

Post by rtlsdrblog » Thu Jun 29, 2017 1:40 am

P-40 Warhawk wrote:I don't know if anyone knows that a lot of disk cone antenna don't have the right connector on them and your problem could be that you have a antenna with the wrong connector on it . A disk cone antenna that is rated at 25 mhz to 1300 mhz should have a female N connector on it . Here is what Amphenol has to say about N connectors . Electrical
Impedance 50 Ohm
Frequency Range 0-11 GHz
VSWR
M30912 Straight Connectors 0-11 GHz 1.30 Max
M30912 Right Angle Connectors 0-11 GHz 1.35 Max
Dielectric Withstanding Voltage 2500 VRMS
Voltage Rating 1500 volts peak
Insulation Resistance 5000 MΩ min
Contact Resistance
Outer Contact 0.2 mΩ
RF Leakage -90 dB min @ 3 GHz
Insertion Loss 0.15 dB max @ 10 GHz

Environmental
Temperature Range:
TFE Insulation -65⁰C to +165⁰C
Copolymer of Styrene -55⁰C to 85⁰C
Weatherproof All series N with gaskets are weatherproof
Hermetic Seals Pass helium leak test of 2 x 10-8 cc/sec
Pressurized Shock Compressed seal Mil-STD-202, Method 213
Vibration Mil-STD-202, Method 204 (test cond. D)
Moisture Resistance MIL-STD-202 Method 106
Corrosion Mil-STD-202, Method 101 ( test cond. B)
Temperature Cycling Mil-STD-202, Method 102 (test cond. D)
Altitude MIL-STD-202 Method 105 (test cond. C)

Mechanical
Mating 5/8-24 threaded coupling
Cable Affixment (Braid or Jacket):
All Crimps Hex braid crimp
Clamps Screw-thread nut and braid clamp
Cable Affixment (Center Conductor):
Crimps Crimp or solder
All Others Solder only
Captivated Contact:
All Crimps Yes
Others Where specified
Cable Retention
Crimps 60-120 lbs
Clamps 30-70 lbs

To many disk cone antennas are sold with SO-239 connectors on them say that they are 25 mhz to 1300 mhz but they are not , the connector is only good to 300 mhz . Here is what Amphenol has to say about that connector .

Description of SO-239 connector
UHF - Invented in the 1930’s by an Amphenol
engineer, E. Clark Quackenbush, for use in the
radio industry.
UHF coaxial connectors are general purpose
units developed for use in low frequency systems
from 0.6 to 300 MHz.
UHF is an acronym for “Ultra High Frequency”.
When the UHF was introduced, 300 MHz was
considered High Frequency.
The coupling on a UHF is threaded.
Since UHF connectors are low cost, the impedance
is variable.
Features/Benefits
• Optional reducing adapters accommodates a
wide range of popular coaxial cables.
• Solder termination types require no special
assembly tools.
• Crimp termination type connector available
provides a lower cost installation method.
• Large size threaded coupling - rugged design.
• Non-demanding specifications and low cost.
Applications
• Antennas
• Cable Assemblies
• CB Radios
• Low Frequency Applications
• Public Address Systems
For RX use only SO-239 should be okay. The loss from the connector will only be probably 1 -2 dB.

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