QRPGuys Lidia 40m Direct Conversion Receiver – $35, the digital dial is an option
The QRPGuys Lidia 40m Direct Conversion Receiver is the creation of SP5DDJ and he has dedicated it to the memory of his wife Lidia. Wim has granted permission for us to produce it as a kit. We are offering it on 40m, but the main IC is rated to 60mHz so it may be configured to work on other HF bands.
The heart of the receiver is a 92 transistor Motorola MC3361C IC that includes an Oscillator, Mixer, and Active Filter. The kit features all through hole components, an integral open frame chassis, with rear BNC antenna connection, 3.5mm earphone jack and a standard 5.5mm x 2.1mm DC power jack. Our kit has the option of adding the QRPGuys thru hole Digital Dial kit to the front panel, which has the mounting holes and window cutout to fit. The layout has a front panel audio gain control, 10 turn pot. for main tuning, board mounted RF gain pot., and a switched adjustable audio filter for CW/SSB reception. Experimentation is always encouraged and we have incorporated solder pads to facilitate trying other filters and varactor combinations. The design allows mounting the main board in an alternate chassis if you desire. Chuck (K7QO) has measured the sensitivity at less than -120dBm or .2uV.
We supply two varactor diodes that can be configured for 150kHz to over 300kHz bandspread. Current usage is ~44mA @12V with our digital dial. The LM386 audio amplifier has enough power to drive a small speaker if desired. Board dimensions are 3.50″w x 2.62″d x 1.75″h. (90mm x 66mm x 44mm) The unit weighs ~4oz. or (113g.). The thru hole digital dial must be ordered separately. On a scale of 1 to 5, 5 being the most difficult, this kit is rated at a 3. Allow about 3 hours to build.,
Shown with Optional Thru Hole Digital Dial
Order the digital dial at https://qrpguys.com/digital-dial-frequency-counter