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Re: 2N2222A upgrade

 

Indeed this is most helpful. The load kit I have has an rf probe built in and the general power readings will help. The heat sinks probably won¡¯t matter unless my antenna works and I can do digital modes :).

That being said I am just trying to get on Hf now. I don¡¯t even know if my v3 is tuned up and if I need to filter it so I am quiet for now. Once the parts get in I will go to town.

KF4FTR

On Tue, Jul 14, 2020 at 4:54 AM Bob Fischer, Fischer Technical Services <FischerTek@...> wrote:

I installed 2N2222A transistors in my Build #3.? Did not add the heat sinks but they shouldn't hurt anything.
I also soldered another 22 Ohm resistor in parallel with each of the emitter resistors.
Build #3 Notes attached.

You might also be interested in the simple Q90 modification results I got from the build I am working on now:

uBITX Build #5? ? July 2020 ?????using V3 board?

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Original Transmit Power into dummy load @ 13.7VDC:? ? ? ? ? 80M = 20W, 40M = 14.5W, 20M = 8.5W?? 17M = 3.5W?? 15M = 1.8W?? 10M = 0.75W

WB8BEL Modifications:

1. Increased the gain of Q90 transmitter amplifier: Shorted emitter resistor R83 New Transmit Power @ 13.7VDC: 80M = 20W, 40M = 16W, 20M = 14W? ? 17M = 5W? ? ?15M = 3W? ? ? 10M = 1.5W


Good Luck.

Bob


From: "Christopher Miller" <djmalak2k6@...>
To: [email protected]
Sent: Tuesday, July 14, 2020 7:23:14 AM
Subject: [BITX20] 2N2222A upgrade


Hello,

I just purchased a half dozen 2n2222A transistors from mouser with heat sinks.

I would just like to verify I purchased the right transistors and heat sinks for my v3 are correct.

Chris
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