Re: RF power chain mods and improvements..

Jerry Gaffke
 

That looks very promising!
Looking forward to seeing where this comes out.

A few obvious observations:

The BFR106@1000 is $0.10, the 2n5109 @ 1000 in a to-39 from Central Semi is $1.50.
Those seem excellent choices if they work.
Looking like these fixes to the uBitx might get done for around $5-$10 more in parts cost, no board changes.

That 2n5109  is cheaper than two of the 2n2222a's in a to-18.
Though the DXT2222A-13  in a SOT-89-3  can be had for $0.10 @ 1000
Central Semi has a 2n5109ub in surface mount, they claim it dissipates a Watt, can't find a price. 

I'm fine if it comes to a fourth stage on a small daughterboard placed between T8-5 and RV1.
if that makes upgrading old boards easier.  (I know, broken record.)

Weird that my search of post  https://groups.io/g/BITX20/message/51550  didn't find any of these higher Ft NPN's.
Either the Mouser parameterized search tool is not very reliable, or me.

Jerry, KE7ER


On Sun, Jun 10, 2018 at 10:54 am, ajparent1/KB1GMX wrote:
Gain and power line up with a few possible solutions listed:

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