KN0CK and KF7LZE Custom HF RTL-SDR Receiver Revision 5

Update: KN0CKs products are now available at

Previously on this blog we’ve seen KN0CK release his custom modified RTL-SDR tuners which have built in upconverters for accessing the HF bands. Revision 5 of the KN0CK receiver is now almost ready for sale, and will be sold over at KF7LZE’s webstore

Revision 5 promises to be lower priced as it will run using the direct sampling mod instead of using an upconverter which would require more components. It will also use a Mini-Circuits MAR 8 wideband amplifier to improve weak signal performance.

Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5
Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5
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The Rev 5 dongle works as well as the version with an upconverter circuit, and covers the same frequency range (500 kHz-55 MHz), but has many fewer parts which allows us to keep the cost down. This method does not allow quadrature sampling, however, as the antenna input to the tuner RFIC has been bypassed; you must use Direct Sampling.


Has anyone tried KN0CK v5 Direct sampling mod based Dongle. Understand that it has a amplifier also.
Does it work good to act as like Upconverter setup?

Does same dongle also allow Quadrature Sampling ?