RTL-SDR (USB) in SDRSharp - defeating frequency limit?

[Llew]

Using my RTL-SDR dongle in SDRSharp, its upper frequency being ~1.76 GHz means I can't set it to anything above this in the frequency input box.

Setting the Shift frequency to my LNB's LOF is of no use if I can't set a transponder's frequency input. Is there a workaround for this?

The second screenshot is one I found on another site showing that it can be set to enter a higher frequency; my pic is the top limit RTL-SDR allows.

Any help appreciated.

 

[FC GD]

i believe the second one is using down-converter and using "shift" just to tune in to right freq. if you want to tune a freq without a down-converter, you can do like i do, use a SDRPlay or Adalm-Pluto that have broader freq tuning range.

if i recall right, a rtl-sdr based R820T2 can tune up to 1700+ LNB Local Oscillator

Updated:

i found this a couple of years ago and it helped me a lot

RTL-SDR: A tool for Visualizing Broadcast Satellite Signals


L-band LNB IF Table (950-2150MHz)
Ku Band
SAT.f LNB Local Oscillator
9750 10600 10700 11300
10700 950 - - -
11700 1950 1100 1000 -
12250 - 1650 1550 950
12750 - 2150 2050 1450

L-band LNB IF Table (950-2150MHz)
C Band
SAT.f LNB Local Oscillator
5150 5750
3400 1750 -
3700 1450 2050
4200 950 1550

 

[Tururu]

I'm a bit lost, I do not use it the truth when I have the Rover SRM50 spectrum analyzer.
The LNB goes from 950 to 2,150Ghz. In theory you could see from 950 to 1760Ghz, then add the local oscillator of the band used.

Playing with a current injector 14/18V and 22khz you could also play with the polarity and band.
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Estoy un poco perdido, no lo uso la verdad al tener el analizador de espectro del Rover SRM50.
Del LNB sale de 950 a 2.150Ghz.
En teoria podrias ver de 950 hasta 1.760Ghz, luego sumas el oscilador local de la banda usada.

Jugando con un un inyector de corriente 14/18V y de 22khz ya podrias jugar tambien con la polaridad y banda.

 

[Llew]

i believe the second one is using down-converter and using "shift" just to tune in to right freq. if you want to tune a freq without a down-converter, you can do like i do, use a SDRPlay or Adalm-Pluto that have broader freq tuning range.

if i recall right, a rtl-sdr based R820T2 can tune up to 1700+9750=11450 mhz

Thanks for that, but I don't need a down converter, as the LNB L-band output is already within the needed frequency range. The Shift frequency I enter defaults to zero, so that is of no use in setting a down-converted frequency, e.g 9.750 GHz.

I'm a bit lost, I do not use it the truth when I have the Rover SRM50 spectrum analyzer.
The LNB goes from 950 to 2,150Ghz. In theory you could see from 950 to 1760Ghz, then add the local oscillator of the band used.

Thanks Tururu - I have a Promax analyser for everyday use; I'm just trying to get the SDR dongle to bend to my will

 

[Tururu]

okay.
You have 2 options

Work with the real frequencies that come down from the LNB.
Work with the real frequencies+local oscillator = frequency that comes down from the satellite.

In Ku band the oscillators to put in the program are ...
Low band 9750
High band 10600.
With these data the program should already show the correct frequencies that you see.
---------
ok.
Tienes 2 opciones.

Tabajar con las frecuencias reales que bajan del LNB.
Trabajar con las frecuencias reales+oscilador local = frecuencia que baja del satelite.

En banda Ku los osciladores a poner en el programa son...
Banda baja 9750
Banda alta 10600.
Con esos datos el programa ya tendria que mostrar las frecuencias correctas que ves.
PD:Buena pesca/Good fishing.

 

[Llew]

okay.
You have 2 options

Work with the real frequencies that come down from the LNB.
Work with the real frequencies+local oscillator = frequency that comes down from the satellite.

In Ku band the oscillators to put in the program are ...
Low band 9750
High band 10600.
With these data the program should already show the correct frequencies that you see.
---------

As I said, I can't enter any frequency above RTL-SDR's upper limit (1.76 GHz).

 

[Tururu]

Work with the real frequencies+local oscillator LNB = frequency that comes down from the satellite.
Trabajar con las frecuencias reales+oscilador local LNB = frecuencia que baja del satelite.
950Mhz -1750Mhz.
Pierdes de 1750Mhz a 2150Mhz./You lose from 1750Mhz to 2150Mhz.


I understood you better, but you do not understand me.

The amateur radio program is not intended for use with an LNB like the CrazyScan companion programs and only works with direct frequencies.
As a comment, prepare a current injector to send 14/18 volts and tone generator of 22khz.
If you do not send tone, you work in low band and everything you find between 0.95 to 1.750Ghz, you have to add 9.75Ghz.
If you send the tone of 22khz to the LNB, to everything you locate, you have to add 10.6Ghz.

If you have an old receiver, you save the invention.
Antenna to the tuner (IN), the OUT mouth to the RTL-SDR-USB tuner.
In the receiver you have to have 4 channels prepared that meet what you need.
1.- Low band channel, vertical. (+ 9.75Ghz.)
2.- Low band channel, horizontal. (+ 9.75Ghz.)
3.- High band channel, vertical. (+ 10.6Ghz.)
4.- High band channel, horizontal. (+ 10.6Ghz.)
-----
Te entendi prefectamente, pero no me entiendes.

El programa de radioaficionados no esta pensado para usar con un LNB como los programas del compañero CrazyScan y solo trabajan con frecuencias directas.
Como comente, prepara un inyector de corriente para mandar 14/18voltios y generador de tono de 22khz.
Si no mandas tono, trabajas en banda baja y todo lo que encuentres entre 0.95 a 1.750Ghz, tienes que sumar 9.75Ghz.
Si mandas el tono de 22khz al LNB, a todo lo que localices, le tienes que sumar 10.6Ghz.

Si tienes un receptor viejo, te ahorras el invento.
Antena al tuner (IN), la boca OUT al sintonizador RTL-SDR-USB.
En el receptor tienes que tener 4 canales preparados que cumplan lo que necesitas.
1.- Canal banda baja, vertical. (+9.75Ghz.)
2.- Canal banda baja, horizontal. (+9.75Ghz.)
3.- Canal banda alta, vertical. (+10.6Ghz.)
4.- Canal banda alta, horizontal. (+10.6Ghz.)
.

 

[Channel Hopper]

When I was running the sdr a month ago, I was able to continue scanning beyond the upper range limit without problem, even though my experimentation on wxtosat didn't go quite to plan.
Once today is over I'll pull the laptop out the cupboard and post the detail.

 

[aceb]

That's odd, there's nothing in the config file that limits the tuning range on a local device, mine will let me set frequencies above 2GHz. The tuner IC in the dongle makes a difference too, something with an E4000 IC will tune up 2200MHz and there's nothing in Sharp or Zadig that can detect what flavour of chip it is.

 

[s-band]

@Llew Set the LOF in exactly the same format as in your 2nd picture and 1st pic attached (Es'hail 2) e.g 9.750.000.000 ( to 1Hz resolution). The Airspy uses the R820 front end as per most of the RTLs (I've never seen an E4000 version RTL). The second pic is using an AD-Pluto which goes to 6GHz (~£70 from Mouser)


The R820 upper frequency varies device-device. When they get hot the upper freq reduces. You can scrape an extra 50MHZ or so by cooling the chip. Many, especially later ones, give up at 1650MHz. To get the upper part of 10.7-11.7, use 10.6G LOF and tune below 950MHz.

 

[Tururu]

The program allows to use an intermediate frequency, it is noted that I do not use it, apologies.

In the link of the companion, indicates that tuner usb-Elonics E4000 reaches up to 2200Mhz, but below is more limited, having to use an RTL2832 tuner with R802T that covers well the bottom, but stays at 1700mhz +/-.
In the pictures we see in the program the option that adds the frequency of the local oscillator to the real frequency that we see on the screen.

The real frequency is what goes down the cable from the LNB (normal), we add the frequency of the LNB locar oscillator and we already know the satellite frequency approximately.
-----
El programa si permite usar una frecuencia intermedia, se nota que no lo uso, disculpas.

En las fotos vemos en el programa la opcion que suma la frecuencia del oscilador local a la frecuencia real que vemos en pantalla.
La frecuencia real, es lo que baja por el cable desde el LNB (normal), le sumamos la frecuencia del oscilador locar del LNB y ya sabesmos la frecuencia del satelite aproximadamente.

En el enlace del compañero, indica que tuner usb-Elonics E4000 alcanza hasta 2200Mhz, pero por abajo esta mas limitado, teniendo que usar un RTL2832 con tuner R802T que cubre bien la parte baja, pero se queda en 1700mhz +/-.

1.- Llew
2.- Internet.
3.- s-band

 

[Llew]

As mentioned before, I can't enter a Shift frequency. Or rather, I can enter one, but it reverts to zero as soon as I move the cursor.

Seems an Airspy unit allows entering scan and shift frequencies in an SDRSharp console; also as you indicated s-band, an AD-Pluto.

Looks like I'll have to save up for an Airspy

Thanks guys for your input. Merry Xmas.

 

[Channel Hopper]

Can you post an image of your dongle ? (oooooerrrr)

 

[s-band]

@Llew Something strange there. Two from V 1.0.0.1443 on W7

and one using V1.0.0.1655

I just noticed that the in later one I used commas , and the earlier full stops . Does it matter?

The Pluto is cheaper, has a much wider bandwidth, higher sample rate and will transmit so I think it's much better value than an Airspy now (for satellite use). The main drawback is that it is a pain to use an external reference on it.

 

[Llew]

@Llew Something strange there. Two from V 1.0.0.1443 on W7
View attachment 121479View attachment 121480
and one using V1.0.0.1655
View attachment 121478
I just noticed that the in later one I used commas , and the earlier full stops . Does it matter?

Many countries use commas instead of full stop decimal separators. Possibly a version intended for one of those. Doesn't matter to me, either methods fail.

The Pluto is cheaper, has a much wider bandwidth, higher sample rate and will transmit so I think it's much better value than an Airspy now (for satellite use). The main drawback is that it is a pain to use an external reference on it.

Noted. I'll check them out.

 

[Llew]

Can you post an image of your dongle ? (oooooerrrr)

Same as this one CH. I've also tried the earlier version (non-V3) which I use for Flight Radar.

 

[Channel Hopper]

Same as this one CH. I've also tried the earlier version (non-V3) which I use for Flight Radar.

View attachment 121481

She does have the 820T2 logo, but have you stripped her and checked the internals ? (Oooooerrrr)

 

[Llew]

She does have the 820T2 logo, but have you stripped her and checked the internals ? (Oooooerrrr)

I have opened one of them up before to enable a Bias-T voltage out, and compared the components used with the info and diagram at RTL-SDR.com, where I purchased it. No reason to believe they're anything other than genuine.
No doubt there are ersatz modules being offered from dubious sellers.

 

[Tururu]

In normal RTL2832U usb, everything is the same.
Even the part of the tuner with chip R820T and R820T2, only changes the chip.
The R820T2 is an improved vesion and with better filters if I remember correctly.
A picture of this usb where the chips are seen.
-------
En los usb normales RTL2832U, todo es igual.
Incluso la parte del tuner con chip R820T y R820T2, solo cambia el chip.
El R820T2 es una vesion mejorada y con mejores filtros si no recuerdo mal.
Una foto de este usb donde se ven los chip.

Internet + Zoom.

 

[Tururu]

RTL2832U_R820T2 ......... 20€ to 10€.