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An ideal amplifier for the KX2 (and KX3)


CR
 

I've just finished building up a superb amplifier kit from Victor and Yana at eb104.ru that uses phase-change cooling. It will output 750 clean SSB watts with 4.5 watts of drive once I replaced the 10-dB attenuator pad with a 4-dB pi pad, namely a shunt 220, a series 24, and a shunt 220. The attenuator is easily accessible without any disassembly. (Arithmetic would suggest that the unmodified amp could be driven to near full coutput by the KX3.)  It employs one BLF188 as the active device with well designed protection from excessive drive, SWR, or drain current.

The amplifier is elegantly constructed, complete, and tested. You need only install it and its connectors into the included enclosure. As I should have expected from phase-change heat transfer, it runs cooler than any amplifier I have ever operated. See details at


I have built many amplifiers using eb104.ru modules. Their boards are of the highest quality in design and performance.

You will have to supply 13.8 VDC, 50--53 VDC at maybe 35 amps, and an external bandswitch box with a wafer switch, since the amp is designed to be bandswitched by a transceiver via the DB25 on the rear panel.  To play it safe I would use a PNP PTT  circuit to protect the KX2's key out circuit from the current drawn by the (three) bandpass filter relays in the amp.


Chuck w8mqw


Drew Vonada-Smith K3PA
 

When you say clean SSB watts, what do you mean specifically?  Are there any IMD figures?  I would not normally associate a 12 V driven amp to be particularly clean.

73,

Drew K3PA


CR
 

Drew:

I don't understand your question. The amplifier is a 53-volt amp. The IMD with PureSignal is below 53 dB.

Chuck w8mqw



On Sat, Mar 2, 2019 at 2:22 PM Drew Vonada-Smith K3PA <drew@...> wrote:

When you say clean SSB watts, what do you mean specifically?  Are there any IMD figures?  I would not normally associate a 12 V driven amp to be particularly clean.

73,

Drew K3PA


Drew Vonada-Smith K3PA
 

Thank you Chuck.  I saw the 13.8 but not the 53V part.  My error.

73,
Drew K3PA