ik1xpv hamradio software & hardware

ExtIO_H101.dll

Following the advice of Claudio Re I1RFQ and Ivan Guerini IW2KBK I spent some time in developing an ExtIO_H101.dll.

This dll follows the Alberto di Bene Winrad specifications for the external I/O DLL.

It allows the use of the H101 SDR receiver with many of the SDR applications that implement the ExtIO standard,

ie: HDSDR, SDRsharper, WinradF...

The last version is: ver 0.13

Here you can download the ExtIO_H101_013.zip  The archive contains the ExtIO_H101.dll ver 0.13

The MD5 hash file signature is c9eaf93506e31afbc1f2d7c3284d2897

It operates with OS in Italian or English

While ExtIO_H101_012.zip runs on English PC.   The archive contains the ExtIO_H101.dll ver 0.12 

The MD5 hash file signature is dfb4a46321dc8380191b6ee98f1c3db3

Copy Extio_H101.dll file into the SDR application directory and then select the ExtIO_H101 from the SDR application setup.

The source code is at www.github.com/ik1xpv/ExtIO_H101

The dll is under development and it is not fully tested, you will use it at your own risk.  

It has been tested in Windows 10, 8, 7 OS with HDSDR, SDRsharper.

Have you fun!

Here after some pictures from Ivan:

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The RTL2832+R820T RF GENERATOR hack 1.0

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The hack 0.9 describes how to modify a RTL2832U+R820T dongle as RF generator.

I connected the generator to two RTL2832U+R820T receivers and I assumed the generator to be in the 0.5-1.5GHz range as indicated by the receivers screens.

That is not correct because the RTL_SDR receiver is sensitive to even harmonics of the tuning frequency.

The generator output is in the VCO range 1.770 - 3.54 GHz.

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The error became evident when I connected the generator to a R&S FSV spectrum analyzer and got the following measures:

 

 

 

 

 

 

 

 Spectrum analyzer settings: Center Frequency 1.8 GHz ; Span 3.6 GHz, Att 10dB.

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Generator SDR# tune: 1GHz,

output spectrum: 2.0GHz (2x)

 

 

 

 

 

 

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Generator SDR# tune: 0.9GHz,

output spectrum: 1.8GHz (2x)

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Generator SDR# tune: 1.4 GHz,

output spectrum: 2.8GHz (2x)

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When the generator is tuned to lower frequency the VCO is tuned to higher harmonics (power of 2).

Generator SDR# tune: 0.5 GHz,

output spectrum: 2.0 GHz ( 4x)

 

 

 

 

 

 

The generated signal is weak while clean.

 

The RTL2832+R820T RF GENERATOR hack 0.9

The RTL2832+R820T RF GENERATOR hack 0.9

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RTL-SDR is a very cheap software defined radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset.
The most common today RTL-SDR dongle contains two primary chips: the Raphael Micro R820T radio tuner and than the Realtek RTL2832U which contains an 8-bit ADC and USB data pump.
During last year the R820T chip has been substituted by the R820T2 with a little better receiver performance.
I bought some R820T2 dongles and I needed a RF generator in the GHz range for comparison.
I investigated the possibility to modify a RTL2832U+R820T dongle to use it as a Radio Frequency Generator and hereafter the results.

The R820T block diagram shows that the internal VCO has no output pin.

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The idea is to use the pin 5 (Det2) that is related to the mixer output. Of course it is not thought to be a RF output, nevertheless part of VCO signal is routed out.

WARNING the modified dongle is no more a RTL-SDR receiver.

It becames a RF generator in the 500-1500 MHz range. ( see Update 1.0 )

The hardware modification is:

  • remove the input capacitor C13 ;
  • remove the bypass capacitor C22 ;
  • remove the protection diode D6 ;
  • wire a capacitor 100pF connecting the Antenna input (D6 pad) to the pin 5 of R820T (ex C22 pad).

Options:

  • remove the IR receiver (not used)
  • replace the blue led with other color (red) to easy recognize the generator modified dongle.

Refer to the following pictures of the hardware modification.

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The following screenshots has been saved while using a RT2832U+R820T2 dongle as receiver and the modified RT2832U+R820T dongle as generator. Generator and Receiver are connected via a coax cable .


( NOTE: the RTL_SDR receiver is sensitive to harmonics of the tuning frequency. The generator output is in the VCO range 1.8 - 3 GHz. See Update1.0 )

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Notice the DVB-T signal reception on the left.

The RF generator has an usable range of 500-1500MHz and the output level is a little weak.

That is not correct! why the RTL_SDR receiver is sensitive to even harmonics of the tuning frequency.The generator output is in the VCO range 1.8 - 3 GHz. See Update 1.0


Future ideas:
The possibility to FM modulate the signal must be verified. The pll filter looks accessible. A PC audio output could be injected to the filter via an attenuator.

Hermes-lite Audio

I investigated the possibility to add a low cost audio interface to Hermes-Lite following the project goals:

  • Maintain enough compatibility with Hermes to use existing Hermes SDR front-end software with no or minor modification
  • Cost of less than $150 (cost includes FPGA board) for hobbyist who build their own.

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https://github.com/ik1xpv/Hermes-Lite/tree/master  https://github.com/ik1xpv/Hermes-Lite/tree/audiocodec_1

 

https://github.com/softerhardware/Hermes-Lite

 

 

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