BS170's did I get fakes?

[Fred]

Had problems getting things running right and was fearful I blew the transistors. I ordered these: https://www.amazon.com/dp/B096W66WKB?ps ... ct_details. However they appear to have the S and D pins reversed. I just "dry fit" them into the board and they blew right away. Put them in backwards and they worked and I'm showing 5W out on 80 meters, however only 2.3 on 40 meters.

Am I going nuts???


Thanks Fred

[gatorjj]

I had a heck of a time replacing the BS170's in terms of getting ones that would work properly. Ones through Amazon and Ebay would blow or insanely overheat. When Mouser finally had some available last month I bought 10, and good thing I did since the first 3 I put in acted similar (3rd one in the series would get instantly and incredibly hot in receive). The second trio from this batch worked great though, maybe too well as I'm getting around 8 watts on some bands now with 80+ efficiency.

If they are not overheating, I think you're good with 5 watts on 80m and 40m just needs the toroids tuned.

I don't know anything about these little guys, though it seems to me something about them these days is a bit hit or miss even from trusted sources. They have greatly improved my solder/desolder skills though

J.J. KF4VE

[Fred]

So did a little checking with a tester and the pinouts are definitely reversed on S and D. The remaining transistor I have from the original kit shows a Vt of 2.3V and a Capacitance of 62 pf. The new ones show a Vt of 2.4 and a Capacitance of 62 pf. I'm assuming these would be fine to use as long as I solder them in "backwards" to the silk screen. Has anyone used these "backwards" 170's with success. If anyone smarter than I knows my gracious thanks. Not wanting to cause issues that I'll regret later down the line.

Thank you all.
Fred

[Jan PA3GGZ]

Yes I did and they work. It is not easy to replace them twice without damage the pcb. I manager.

[LILO]

Easy, actually.
Cut the legs and then desolder them individually.