Flexers may be interested in four photos I've posted to the Web: http://www.guyatkins.com/files/sdr_front.jpg Front of homebrew SDR-1000/HPSDR (receive-only) enclosure with Griffin Powermate tuning knob and LW, MW1, MW2, and Bypass filter position switch.
http://www.guyatkins.com/files/sdr_rear.jpg Rear view with USB ports for Griffin Powermate tuning knob and PC control line, antenna input BNC, audio in/out jacks, and cooling fan. http://www.guyatkins.com/files/sdr_inside.jpg Inside view, showing original SDR-1000 board stack along side of HPSDR "Ozy" control board and "Janus" sound card replacement board; W1VLF custom low pass filters for LW, MW1, MW2 with shielded rotary switch; cooling fan; custom, balanced I/Q connection between SDR-1000 and Janus board; various other custom cables, including short DB25-to-DB25 IDC ribbon cable (replaces bulky parallel port cabling). Torroid and binocular core ferrites used throughout for RFI supression. http://www.guyatkins.com/files/sdr_inside2.jpg Another inside view of the homebrew SDR-1000/HPSDR receiver enclosure. I've recently completed the combining of my receive-only SDR-1000, HPSDR Janus and Ozy boards, and Paul Cianciolo W1VLF's low pass filter modules into a single enclosure. This effort does away with three separate assemblies and a snarl of external cabling, and makes the whole affair more compact and neater. I was going to need to build an enclosure for the HPSDR boards anyway, so I decided to repackage the entire SDR radio's components under "one roof." A Griffin Powermate USB knob is attached to the cabinet front for "traditional" knob tuning to complement keyboard/mouse control. The low pass filtering for longwave, medium wave lowband, medium wave highband, and a bypass position is accomplished by a four-position rotary switch to the left of the tuning knob. I avoided having to use a separate power supply for the HPSDR boards' +12V, -12V, and +5V requirements by supplying appropriate voltages directly from the SDR-1000 board stack. The -12VDC regulator on the HPSDR Janus board conveniently uses the -15V output from the SDR-1000's DC-DC converter as its input supply. I previously modded the DC-DC converter by replacing the stock chip with a much higher quality, low-RFI module bought on Ebay. (No more wandering spurs!) The SDR board stack conveniently sits on some unused Atlas board DIN connectors, and four spacers on the stack are insulated from the bottom of the Janus board. The stack is secured to Atlas with multiple loops of monofilament fishing line, around the stack spacers and tied through plated-thru holes in Atlas. A thin 1/8" sheet of medium-density foam fits between the upper Ten-Tec enclosure cover and the edges of all boards except Atlas. The slight pressure with this foam completes the securing of the boards and makes the assembly quite stable. One of the DIN connectors is still available for the future Mercury board, although I will have to move the project to a larger enclosure if I want to make more slots accessible for other HPSDR boards/devices. Lettering on the enclosure (a Ten-Tec BK-959) is still to come, but for now it's a fully functional SDR-1000 with improved dynamic range and lowered noise floor due to the HPSDR boards replacing the former Presonus Firebox sound card. I have yet to do any serious DXing with the radio connected to the HPSDR boards, since I hadn't used them until this project was completed. However, I'm heading north to the Queen Charlotte Islands (BC) today for a week-long DXpedition with other MW enthusiasts...the setup will get a through test soon! More details and photos on the low pass filters I use for trans-Pacific MW DXing with the SDR-1000 can be found here: www.sdr-1000.blogspot.com Guy Atkins KE7MAV Puyallup, WA _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
