开云体育

Rich, you asking for the bottom of the board, correct? 73, Cliff, AE5ZA

Well John, add another mystery to the list, at least this one hopefully won't be so difficult to solve. I'm happily going along decoding and sending CQ in Wsjtx and I noticed that all signals on the

Hello John Certainly it is! And remarkably high performance at a low cost and simple implementation! I'm not sure this is the case. When you sweep the RF, at each of the 80 points on an RF sweep

Thank you so much Bojan and Gyula - I just have to find the short circuit now!

Hi Tony, Hans et al, As I had posted earlier, modelling the output transformer for QDX/QMX is tricky business! Proper modeling of the output transformer is complicated at the outset. There are

A year or two ago I was pulling my hair out with some devices on USB having the same intermittent problems. Turns out that several USB cable, even new ones were badly out of tolerance and not mating

Hi Hans, You make valid points, especially about modeling the output transformer. I’ll leave this question to JZ as he has more expertise in this particular area. I do think his model is fairly

Try another USB cable. Larry KB3CUF

(repost as I forgot to include a subject after the hashtags before, sri bout that). I had my QDX (rev 5, fw 1.09) working a few weeks ago, sending/receiving OTA just fine. Today, I fire it up and the

In my case, I have only seen the sound card show up as ttyACM0 or ttyACM1, usually 0. I've not looked to see if there is a USB0 or USB1 present before/after the SC disappears. BTW, sorry about

Hi Ryuji, The Tayloe detector/downconverter is a complex and interesting entity! What are you taking for the impedance at the input of that circuit? Dan Tayloe, in private communication with Steve

Hi Cliff, Would you please take a good clear high resolution picture of your board, zoomed-in on the four PA transistors, and post it up here for us? Thanks! Rich

Martin / Luc, Sorry I missed all three sessions yesterday. Forgot about the event till after the first session and was busy with job hunting activities for the second and third sessions. (Need a job

I revisited this issue with morning coffee. The problem of unwanted interactions between the LPF and BPF is most severe where the BPF's center frequency is near the corner frequency of the connected

Dan, did you check the settings in the terminal program to see that all of the bands are set to active? It's possible that some stray RF of something else reset them. -- 73, Dan - W2DLC

No problem, Cliff! We still have a mystery on our hands, though. I hope we can get to understand the transistor failures! Perhaps run your radio at reduced power for a while? JZ

Hey Bob, Please check each wall wart that you might think of using.? Many are not regulated, and produce unloaded voltages far in excess of the numbers on the case.? There have been issues here on

Hi Gyula I measured VDD 2.99v when powered on. Mike

3v is better than battery voltage. -mike/w1mt

Hi Mike PWR_HLD when battery connected is? zero PWR_HLD when on/off is pressed is 3v and says at 3v pressed or not. Mike