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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W4RFM on January 10, 2019, 06:02:12 PM



Title: 2 tube oscillator and buffer circuit
Post by: W4RFM on January 10, 2019, 06:02:12 PM
Does anyone have a favorite 2 tube oscillator and buffer circuit? I am thinking I saw a 6AG7 and a 6L6 circuit, that would be used with a crystal, to drive the input stage of my future AM rig.  I only need 5 watts or so.


Title: Re: 2 tube oscillator and buffer circuit
Post by: W9ZSL on January 10, 2019, 07:53:38 PM
Go to the good old 2-tuber in the '49 handbook. Here's the one I built a few weeks ago and it gives me around 5 watts out. Would have been more, but the power transformer I used came up a few volts short! It's shown here with the parallel 807 amp that I built on that chassis I got from you.


Title: Re: 2 tube oscillator and buffer circuit
Post by: W4RFM on January 10, 2019, 08:09:48 PM
Is that the "Simple Transmitter RF Unit" in the west coast handbook? Page 48?  Now I see where Heath Kit got the plan for the AT-1.
Thanks Michael.


Title: Re: 2 tube oscillator and buffer circuit
Post by: w9jsw on January 11, 2019, 06:57:47 AM
This design was in ER a while ago. I have the text for the article as well.


Title: Re: 2 tube oscillator and buffer circuit
Post by: W9ZSL on January 11, 2019, 11:09:11 AM
You bet Bob. I just built an AT-1 and not only are the circuits similar but they sound the same and put out about the same amount of power. Either circuit can be modified for a VFO. The main concern about the unit from the Handbook is if the plate of the oscillator has a coil, the 6L6 must act as a multiplier.
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