开云体育

That's interesting. Perhaps the bias wants to be higher than 100ma. Though as I recall, wa2eby was recommending 10ma of bias, and is quite competent. As is Allison. Perhaps there's IMD contributions

I somewhat agree with Tim on this, but will go out on a limb, risk getting flamed and say I don't think a reverse power measurement in firmware is really necessary. In my opinion, two absolutely

The goal is whatever we want it to be. Showing SWR on the uBitx makes it useful for verifying an antenna system is working? without having to lug about an extra box, especially when operating

Jerry, I tried raising the voltage on my final to 24v. It didn't help the 3rd order IMD at all. I suspect most of the IMD is coming from crossover distortion, not flat-topping. tim ab0wr "Jerry Gaffke

I vote for making the PA output transformer primary winding centertapped, and feeding Vcc into that center tap instead of using the two chokes from Vcc to the drains. When using LTSpice to simulate it

Jerry, What is the goal here? Is a wattmeter function really needed inside the ubitx? Or would it be better as an external attachment that can be used with other equipment? For me, measurement of the

Here's my unproven code for displaying forward and reverse power in Watts plus SWR on the bottom line of the 16x2 LCD, when using a TandemMatch with diode detectors. It's actually quite simple and not

I'm using a direct probe. The 815 has a 50ohm input which should be a match to most points in the ubitx. At least a close enough match to not directly affect the circuits operation. I suppose I could

Ashhar… see this result too. The PA output transformer is sub-optimal so some of us have found. Needs to be 2T:3T and frequency compensated by a cap across the primary. My simulations show something

It is admittedly obtuse code.?? Pretty much by nature, as the registers on the si5351 are rather obtuse. But I convinced myself it was correct (with no overflows) before releasing it. I doubt most

Thanks...I've downloaded...I'll check it out. V n2aie

the diode on the bottom of the nano. near the usb conn. i put in a 1n400xs, fixes most of them. stinky

“However, the new PCB has pads for the RD16HHF1” Thank you !!!!!! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton,

Yes, you’ve got it. The Nyquist sampling theory sets the limit of resolving the Power (and hence SWR), and the A/D rate needs to be faster than that or it won’t work properly. For a 3 KHz signal

Also have some MPSA13 coming in, those are the darlington, not the MPSA18, sorry about the confusion. Part number is pretty well the same except one number.? The 13 is what I meant to ask about using

The hfe on these is typically 1150. Max is 1500, min is 500. I was curious as to if the higher gain might help with the drive on 30 meters and up.

my favorite to92 npn gain guy. bes ide the xx390x twins the best transistor you can buy. tayda sells .12 each hfe ~400-500

Thank you, Jerry - that helps guide me through the code and chip documentation (I was getting puzzled at doing all of these computations in unsigned 32-bit integer space with overflows and stuff to

Yes, the plan was to use an RD device for the new version. We ran into availability issues. The lead time from Mitsuibishi was 10 weeks. So, I took a call to continue with the IRF510s. However, the

Ashar, Is this mod going to be implemented on new production? Thanks! 73 Steve G1KQH