Great idea solder leads to the SMD Larry! steve > On Oct 22, 2020, at 11:08 AM, Larry <[email protected]> wrote: > > FYI, since the genuine 2N5109 is so difficult to source (and the 2N3866), you > might want to look at using a DCP68. This is a surface mount device that will > electrically replace the 2N5109 in the W7IUV preamp provided you don't need > to operate it at frequencies higher than 3 Mhz. > > I have successfully used this device by simply soldering short leads on the > part and installing it directly in place of the 2N5109. You do need to > provide a heat sink of some sort. I have soldered the collector pad down to a > 3/4 inch square pad on an PCB and have also just soldered a 3/4 inch square, > or larger, piece of copper sheet directly to the collector tab. > > The measured NF at 137 kHz and 475kHz is about 1 dB better than the 5109 and > about 0.5 dB better on 1.8 Mhz. Best of all is that it costs less than a buck > and is available from most common distributors. > > 73, > > Larry - W7IUV > > > > > > On 10/22/2020 9:22 AM, Edward stallman wrote: >> I remember about a year ago a discussion not to buy the 2n5109 transistors >> from E-Bay sellers . Some searching shows the 2n5109 has been discontinued >> for many years . So is anyone that's been saving one for many years willing >> to part with it ? I'm using it in a W7IUV pre-amp . >> Thanks Ed N5DG >> _________________ >> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
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