Matching 50 ohm antenna to 6V6 transmitter

The Pastime Projects 6V6 transmitter kit is based on a design that was first published around 1948.  Our kit followed the design shown in several ARRL publications, including the 1948 handbook . A reproduction of that article is included in each kit, with ARRL full written permission.

For many years I took a couple reproductions of this transmitter to Ohio and Indiana ham-fests. Many hams who were licences as novices in the 1950 and 1960 years, came up to my display and said “I remember when I was starting out I built one of those transmitters”.  Later, when Pastime Projects introduced the kit for sale,  we called it the “Remember When” transmitter kit.

One common thread among the hams who built this kit was a problem with second harmonic interference – as often reported back to the unlucky ham by the F.C.C. !  To prevent similar problems with our current kit, we researched and built harmonic filters which we sell. These are the latest and greatest design. Read more about them on our web site.  They do require point to point wiring on a perfboard.  And, you wind the toroid coils.  But not bad for the price.

The problem is you need a low impedance match from the transmitter to the coaxial coil to conveniently match the low pass and/or second harmonic filters.  We will discuss the methods of matching the 6V6 output link to a 50 or 75 ohm load.  If your antenna is a balanced line,  we will cover that conversion  from 50 ohms to 200 ohms a little later.

We are writing this up in our monthly e-mail newsletter. If you want a copy email us at pastimeprojects@yahoo.com.  Meanwhile watch here as we discuss the ongoing experiments we are conducting right now.  We are having good results with matching the link to a 50 ohm dummy load with little if any  reflected power….. in other words, low SWR. Stay tuned! 

73 Glenn NN8G 

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