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 IRF510 heat sink. The assembly now involves the Device soldered to the copper plate the mica insulator between the copper plate and the U Channel and then a 4-40 tapped hole into the U Channel. A wire soldered to the copper plate is the Drain connection.

73's

Pete N6QW

January 26, 2024. A simple CW Transceiver/Transmitter

Cruise through the lower part of the ham bands bands and what do you hear? Well, FT-8 and CW. Often you will not hear any SSB stations yet go to the lower part of the bands, and it is a cacophony (I love that word) of bad sounding signals and some high-speed keying. Fast is not so much of the issue as is bad, run together and jerky keying. But none the less our hobby started there. So, you could crank down your ICOM 7300 and watch the waterfall on CW or you could homebrew a radio. Actually, to do CW right you need more thought up front than you do with a SSB transceiver. Often, I will state that a CW Transceiver is much more difficult to build than a simple SSB rig. I published two articles in QRP Quarterly on CW transceivers and all I got was a yawn so maybe history will repeat itself. Yawn! 30M CW Transceiver with RIT! Of interest is that the LO is a Varactor tuned LC oscillator using a NE602. Look closely at the RIT circuit which is only activated on ...

March 31, 2024. Happy Easter to those who celebrate this day.

What a great day to Binge on Chocolate and experience the pain of that filling that has been leaking. I would be in that category with the leaking filling(s) had I not just spent an amount equivalent to one of the fancy new uptown appliance box transceivers on two filling repairs. Well at least I can binge on the Chocolate bunnies without fear of pain. Regrettably everything appears to have jumped in price including the price of parts. Well not so much the parts as the shipping costs. That notably is seen in the eBay treasures. I spotted a nice heathkit DX-20 for about $50 and the shipping was $65. Likely it is a twofer with part being a way to in effect charge a higher price by inflating the shipping and in part by increased shipping costs. Shipping with insurance across the US was about $150 for this jewel and that was three years ago. 6AM on the Left Coast ~ 20M Easter Sunday! My only hope is the cost of Chocolate Bunnies remains steady although a pound of See's Candies f...

August 30, 2024. A PNP 20M SSB Transceiver

Shown below is the Block Diagram for the 20M PNP SSB Transceiver steered in the Transmit Mode . The components shown in the dotted block are relay steered so that the block module is single pass and amplifies in a single direction. The Block diagram show steered in Transmit. Essentially the steering process works so that the IF Module input follows the Balanced Modulator on Transmit and then the input side follows the Receive Mixer on Receive. All done with some relays and a bit of RG174U coax. For those who count things in detail, this block diagram is not unlike what was used for the PSSST Transceiver which can be found on my website . Yes, a warmed over P3ST only using PNP devices. TYGNYBNT. 73's Pete N6QW

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