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April 18, 2024. Linear Amplifiers for your QRP Radio

The following subject is on par to bringing with you an ice chest of Cold Beer to a Tent Revival Meeting on a hot July Sunday afternoon. [It is with uncertainty that you would be marched out of the tent or mobbed to get a cold brew.] Linear Amp with Tubes.   Yes, this AI stuff works as this showed up on my Android phone and I do not know how it did. One of the early on paragraphs states this is a linear amp for QRP Transceivers so there is a connection to this blog.  I just had a revelation that QRP follows QRO in an alphabetical listing -- so who ever came up with the Q Signals was a visionary that you must step down for less fire in the wire. I have many QRP homebrew transceivers, and you can spot them on my You Tube channel, so they do exist. Literally all of them include the ability to switch in an external linear amp. My current  40M homebrew SDR Radio can operate at 5 watts, 120 watts or 600+ watts. That is a lot of fire in the wire .  I must admit that I had to add a whole bag o
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April 17, 2024. Something you can build.

  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

April 16, 2024. So you didn't get a refund?

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