Re: TX project advice

Donald Kelly

Jon - Congratulations on building your DC receiver. Not many people build from scratch and even fewer build receivers.


Just a thought for future experimentation. You have “Experimental Methods in RF Design”. Later in the book you will find KK7B’s section on higher performance DC receivers.

They are a lot of fun to build.


A good first transmitter design might include W7ZOI’s Universal QRP Transmitter. It is a 1 to 1.5W transmitter using very available parts. It can be a driver for a more powerful TX later on.


This is a good reproduction I found on the WEB. I could send you a copy of the chapter from “Solid State Design for the Radio Amateur”. It is a classic MOPA format that modernized the

legendary designs like the 6AG7/6L6 transmitters many of us used as Novices.


It is a limited transmitter but will teach you a lot about TX construction. I have used various power amplifiers over the years.

I casually operated 1.5W with a DC receiver and a simple TX like this for over a year and logged 40 state and 3 foreign countries.




This is a 20W transmitter I built a few years ago. The basic driver is about 1W driving a 2SC1307. It is VXO and covers about 6KHz.


Good luck with your project.







From: 4sqrp@... [mailto:4sqrp@...]
Sent: Friday, May 08, 2015 1:05 PM
To: qrp-l@...; qrp-tech@...; 4sqrp@...; ba_radio_builders@...
Subject: [4sqrp] TX project advice



Greetings Everyone,


I finally have my 40 meter DC receiver in band and working well and the helically wound vertical is all but done. While I want to tweak the AF amp and do some filtering my biggest concern is actually getting on the air before FD.


To this end, I need to build a transmitter. My specifications are... 40 meter, under 5 watts, simple design, commonly/currently available and inexpensive or easily manufactured parts, and now the kicker SSB/CW.


A tall order but hey, you guys, and gals, are the ones who would know. I am skilled in assembly but my EE/RF design skills are still in there infancy. Any suggestions in this area would be greatly appreciated.



~Jon Wanzer KK6GXG

(408) 515-3583
jon@... |

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