KN0CK Amplified RTLSDR for HF Rev. 5 is Back!

After some technical difficulties, the KN0CK Amplified RTLSDR for HF Rev. 5 is back! Now for sale directly through blog.KF7LZE, and including free shipping in the United States, and a free PAL to BNC adapter with purchase! Everything you need to get started quickly – just add a computer and your favorite software which can address the dongle in direct sampling mode and you’re good to go!

Cased Direct Sampling Receiver


This micro-sized dongle is purpose-built for receiving transmissions from 500 KHz – 54 MHz (MW ~ 6m) and features an internal daughterboard, low-pass filter to reject interference, and a new direct sampling modification which reduces internal spurious emissions and harmonics from the oscillator/mixer designs used by other converters.

Uncased Direct Sampling Receiver


Inside, the tiny permanently-mounted daughterboard contains a Mini-Circuits MAR-8A amplifier and low-pass filter contained entirely within the dongle’s shell – no bulky converter boards or external accessories! Each amplifier board is hand-made in the USA and each is thoroughly tested after assembly prior to shipping. No soldering or additional drivers required – just your favorite direct-sampling capable SDR application and the most recent set of RTLSDR drivers will do.

Available now for $85.00 per dongle, including a free antenna adapter and free shipping in the United States!




KN0CK and KF7LZE RTLSDR for HF Back In Stock at!

Edit: is offline, but still for sale! Click through. 

We’ve completed the next production run of Rev 5 direct-sampling RTLSDR with HF converters by KN0CK !

Rev 5 Direct Sampling HF RTLSDR with Amplifier

For Sale: The KN0CK and KF7LZE RTLSDR for HF Rev. 5!

I’m happy to announce that Rev 5 of the KN0CK and KF7LZE RTLSDR for HF is now available for sale in its 5th iteration – now featuring Direct Sampling, while still keeping the familiar wide-band pre-amplifier! On account of the reduced parts count, we’re able to offer it at a discount over the previous version too. Yours for only $85.00 with free shipping and a plug adapter!

Uncased Direct Sampling Receiver

Get yours today!

Previously seen at

Coming Soon: KN0CK and KF7LZE RTLSDR Receiver Rev. 5!

Edited 6/10/2014: Now for sale directly at!

I’m proud to announce that in just a few days, in cooperation with KN0CK will be releasing Rev. 5 of the popular RTLSDR Integrated Upconverter with a brand new design and smaller form factor!

This new design will feature a lower price-point and is designed for operation in direct sampling mode for improved flexibility across the entire frequency range. It contains the familiar Mini-Circuits MAR 8 wideband amplifier, to deliver unprecedented weak signal performance when paired with a quality receiving antenna setup.

Available NOW!

KN0CK HF Converter Rev. 4 is Released!

The complete Rev 3 KN0CK HF Converter has sold out and been discontinued. That’s okay, though, because it’s been replaced with the KN0CK RTLSDR for HF Revision 4! This model incorporates a lot of the feedback from the community about the old stack – especially the expanded tuning range, since the new model can now upconvert from the 6m band (54 MHz) versus 30 MHz with the previous model. It’s even smaller and still manages to be easier to manufacture, too, and it retains the core Mini-Circuits pre-amplifier and 120MHz local oscillator frequency.

Receiver Closed Up

Receiver Opened Up1

It’s a pretty great performer, too.


Buy Here

Coming Soon: KN0CK Rev B Integrated HF RTLSDR

Marty KN0CK developed a very interesting v1.0 HF converter based on surface mount technology that fits inside the casing of an RTLSDR tuner dongle. He’s recently sent me schematics for the revision, which should offer even better performance!

This new iteration has a few major upgrades from the previous – an ESD protection diode on the input, and an optional Mini-Circuits MAR 8+ RF preamplifier which should really draw out some weak signals. Nice weather is coming up soon and once I have some free time, I’ll string up my long antenna – this should really pick out the weak shortwave signals I love hunting for.

Buy Now!


KN0CK HF Upconverter Fits Inside the USB Tuner’s Enclosure

Marty KN0CK sent me some details to publish about his great looking miniature HF upconverter board for the RTLSDR, the HF Alchemy DVB-T Active HF Upconverter. It’s an incredibly miniature SMT board with an SA612 mixer and SMT oscillator, and with some very careful soldering the entire board fits inside the housing and draws its power from the tuner’s USB port. The design upconverts at 120MHz, which is well out of the FM band to reduce the possibility of interference from strong local stations. A 40 MHz low-pass filter on the input further reduces interference. Marty reports it works GREAT!

I also had the opportunity to test an identical dongle and it was very easy to use. It requires a PAL adapter, but most of these dongles need an adapter and this one wasn’t difficult to locate; the integrated form factor is excellent. It’s very sensitive, a bit more-so than my other tuner module even, and the integrated form factor is perfect. It would be very easy to purchase an active USB extension cable and locate this integrated SDR in a shielded enclosure at your antenna’s feed point for even lower losses and versatility.

Update 1/28/2014: We’re up to Rev 5!

Thanks for sending this in, Marty!