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The KF5CCN Heathkit Page


I have alway wanted a "Big Tube Linear" since I was a kid.
I finally got one on April 28, 2010. It is a Heathkit SB-201 with a pair of 572B Tramsmitting tubes. Below is some information and history about this vintage boatanchor, a workhorse of an amplifier.

SB-201

The Heathkit SB-200/201 Vintage Linear Amplifier

A Great Buy at Today’s Prices

Sooner or later it seems that every amateur that operates on the HF bands wants to try to boost power with a tube type linear amplifier. Getting through the QRM can often make the difference in enjoying a good solid QSO in today’s crowded bands. Also it just feels great to get good signal reports. With prices for new commercial linear amplifiers right up there with new solid state transceivers, considering used vintage equipment presents an option that works a lot better for those of us with limited budgets. I suspect that many amateurs are fearful that older amplifiers will not work, or if they do, not for long. If you understand the circuits and get comfortable with the nuances of the older vintage radios you can keep them going for years with a minimum of effort, and they will perform with the best of the commercial units watt for watt.

One of the best buys on the market today is the Heathkit SB 200 and SB201. These old workhorses were built 20 plus years ago, and there are still a whole bunch of them out there doing yeoman’s duty on a daily basis. These amplifiers often sell for around $300 or less. When you consider that a new high voltage transformer alone would cost you more than this it seems unreal to me. At this price about the only way you could lose would be if the power transformer were inoperative. Further, the SB 200 uses a pair of relatively inexpensive 572B tubes, which can put out a nice solid signal approaching 600 watts (output).







Here we see the SB-201 with a true PEP reading meter, indicating 800 Watts Continuous carrier



Showing 800 Watts again




The PEP meter sporting sexy blue LED lamps. Notice the two supplemental cooling fans on top. This thing puts out some heat! The original record player motor fan inside was replaced with a 120 VAC muffin fan. The box behind the fans on top is a dry dummy load.



Here is the top "hood" open revealing the RF shield.



RF shield removed, exposing the huge 572B triode tubes. The ruler shows 6 inches, the length of the tubes.



Here are the tubes lit in all their glory.



Click here or the above picture for a short Quick Time movie of the directly heated cathode tubes quickly lighting up to the intensity of a 15 Watt lightbulb.,





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