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 5/1/2013: KN0CK is releasing a Rev B! I have a teaser.



Thanks for sending this in, Marty!

looks like you’ve got it knocked!
The schematic and PCB don’t match. L1/C4/C7/C8/C11, maybe more are all mixed up.
No C6 in circuit diagram.
It looks like I’ve mixed up diagrams from different revisions of the board, it’s an evolving product. I’ll try and get the current revision schematics from KN0CK and replace them here. Thanks for pointing that out!