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Grant, If all is setup correctly try running the QDX on a lower power. Maybe 7 volts. I've not experienced it myself (I run max 1 watt on my QDX) but the TCXO might heat up too quickly and drift too

Hi, yes, you need the pin LCD D6 to be off GND. Perhaps you can follow the path as in the attachment and look under the microscope for the short. And hope that the pin 5 has survived. 73 Bojan

Hi Ron, That pin 5 should not be shorted to GND. ?I always use a milliohm meter to try to find the precise location of a short. ?Maybe it’s within the processor or along the pc trace somewhere.

Apologies for the epic reply delay - just saw your comment while searching .. So just to complete the thread The DPDT gold contact? (<20V *and* 0.4VA max so.. )? ultra low voltage /current switch

I am looking for confirmation that my thinking is right. I was one WSPR 20m today. I was spotting signals from US (12821 km at 0.2 W) and ZL (2507 km at 0.2 W) but no one picked up my beacons. I was

I replaced the standard transformer with the WTST today to see how it compares on the 80-60-40-30-20m build. There was a worthwhile increase in power on all bands and maybe a smidge more efficiency.?

In version 1_00_009 and earlier of QMX firmware, the PTT out is not working. It's on Hans's to-do list. PTT out should magically start working for you, hopefully in the next version of QMX

Hello QRP Labs Community, I recently placed an order for the QCX Mini Kit about five days ago, and I'm eagerly looking forward to receiving it. However, I've noticed that my order hasn't shipped yet,

I have to give the Tayloe circuit and its intrinsic BPF a big shout-out here! When I set my QDX-HB to 30m, using its 20m filters, reception on 30m is great and there is no sign of the monster SWBC or

For the life of me I can’t figure out why no matter what I do. If the QMX is powered on my DVM sees 5v on the ring of PTT. I have gone back over the main board looking for shorts. I have done a

H i Hans, S orry, I didn't describe it clearly enough: I measured with the oscilloscope while pressing the T key in the diagnostic screen. T hat is, during normal transmission. I t doesn't matter

@DL2ARL yes, my qcx mini was built for 17m, and I use it just like that on 20m Power on 20m drops to abt? 80%, so only 4W versus 5W on 17m Receive is also 1 S-point weaker, but? a little trick is

Thanks Dan I had to reflow about half my band pass filters but after that transmit and receive worked. It looks I need to play around with my windings on my BPFs to get better 40m and 20m. 9V supply

Hello Jorg There may not be any actual problem. Clk2 is used as a signal generator for the RF sweeps, as well as the signal source for transmit. When you do an RF sweep it is normal for the Clk2

Hello Stephan I don't agree... the LPF does indeed suffice for rejection of the harmonic content. I believe the BPF in general provides an improvement in performance. The QSD has very high

I have a strange problem where often the QMX boots up fine but after a few seconds, the screen goes darkish in terms of contrast where I have to angle it to read characters. At the same time, the

one of the nicest simple PSU? DIY designs is the Weber one . Fred at Far circuits in chicagoland can sell you a PCB for this for about 8 dollars . THe biggest issue is to find good quality BIG

So, I had the 20m sensitivity issues myself, and rather than futzing around with it I had the realization that the RF is passing through a 5th order lpf on its way into the radio, so another series

I did have to reinstall the firmware software. the qmx drive showed up and I copied the firmware onto it and it installed per the manual. Then the screen display turned on and it installed the

Nic, Congrats on getting your rig up and running. I just did the same thing with my rig after getting replacement SMPSs from Hans. However, I replaced the 6.3 V C107 with a 10 V item before installing