Re: [Elecraft] [K2] T/R switching

2012-03-15 Thread Don Wilhelm
As I recall, 500 mV drop across a saturated 2N3906 is not unusual - I think all is well. 73, Don W3FPR On 3/15/2012 6:55 PM, picmas...@mail.bg wrote: > Hi Don, > > Thanks for your answer. The output of the 8V voltage regulator is just > perfect (for a 10% device) - 7.98V. I was wondering why I g

Re: [Elecraft] [K2] T/R switching

2012-03-15 Thread Don Wilhelm
Nickolay, Yes, anti-static measures are important when handling the 2N7000 (and many more devices. If you do not have a goo anti-static mat and a wrist strap, then shorting all pins together until after the device is soldered in place is a good preventative measure. 73, Don W3FPR On 3/15/2012

Re: [Elecraft] [K2] T/R switching

2012-03-15 Thread picmaster
Hi Don, Thanks for your answer. The output of the 8V voltage regulator is just perfect (for a 10% device) - 7.98V. I was wondering why I get 500mV voltage drop across Q1 & Q2, but if you say that's OK, then I'm fine. Slightly offtopic - I had also another failure of 2N7000 - again in Control Boa

Re: [Elecraft] [K2] T/R switching

2012-03-15 Thread Don Wilhelm
Sorry for the blank post, it was a "slip of the finger" problem. The 2N7000 is a great switching FET, but as you noticed is susceptible to ESD damage until it is mounted in its circuit, and then the static susceptibility is contained. As for your fix and substitution, measure the output of the

Re: [Elecraft] [K2] T/R switching

2012-03-15 Thread Don Wilhelm
On 3/15/2012 12:26 PM, picmas...@mail.bg wrote: > Hello fellow hams, > > One more K2 (#7293) was born this week in Europe - thanks to the Elecraft > team for designing this kit and making it available for the ham crowd. > > The radio is now assembled, but I have small issues with the testing. Du

[Elecraft] [K2] T/R switching

2012-03-15 Thread picmaster
Hello fellow hams, One more K2 (#7293) was born this week in Europe - thanks to the Elecraft team for designing this kit and making it available for the ham crowd. The radio is now assembled, but I have small issues with the testing. During the initial testing on 40m reception the radio was alm