Check N2CQR's Solder Smoke Daily News posting yesterday for a really super neat Direct Conversion Receiver project (DCR) from Geoff, N6GWB. One of the circuits he mentions he used with the J310's configured as a Dual Gate MOSFET is based on this design from me. Not a lot of parts but surely a lot of performance. For the full detail of the J310 DCR check my N6QW website. The direct conversion receiver offers a superb result for not a lot of hardware nor lot of money. Yes, something for those who had to pay Uncle Sam some $$$ a few days ago. Notably this same circuit topology was used as an IF amp stage by substituting a fixed Bias on Gate #2. I found a module using this approach in the Junk Box and have a "sorta of working" SSB Transceiver using that old module. You will see that shortly. Yes, it has a homebrew 4.9152 MHz four pole filter and for those with a Nano VNA you could actually use that jewel on that board. I mentioned to Geoff, that a companion project woul
Well, lots of folks didn't. But here is something to take your mind off of having to write the IRS a big check. A first look of a potential amplifier circuit using a P Type MOSFET. IRF9Z34SPBF ~ $1.92 @ Digi Key The Green line is the output and the Blue line is the input. The simulation shows about a 30dB gain at 15MHz. The device in the LT Spice simulation was from their library. This is an obsolete device, and the Substitute is the IRF9Z34SPBF from Digi Key. I do not know how valid this is as a working piece of hardware, but these results look promising as we march toward a PNP version of the P3ST. The secret of the mounting of this SMD device is to use a small piece of copper sheet available from Jeff Bezos roughly the size of a postage stamp and solder the tab to the copper plate allowing enough extra space at the top to pass an insulator for a 4-40 bolt as found in the TO-220 transistor insulator kits. Go back a few posts about the use of the aluminum U Channel for the