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I've had a really odd situation with presets.

Some of mine, when recalled, present similar to as described here.?

My 80m & 40m though often Txs fine but at (relatively) insane power. 8-10w out and this is verified on an external power meter and PuTTY.

I too have spotted using them.?

Ok, so given both 60 and 40 share the same rx filter then I wonder if the fault is inducing noise from elsewhere in the radio due to a fault.
This could be a solder bridge, dry joint or any of the usual faults we put in when building a radio : )

The LPF forms part of the RX chain, it would be worth checking that, or even swapping LPF's between 30 and 60/40 to see if the fault moves / changes.

Warren.

Yes 60m has similar noise, my antenna is for 40m so too small for 60m.??

The noise is high on 40m but not 30m.? Signals on 40m are very weak.? I have other qrp rigs and at nite there are many signals on 40m but I can usually only hear 1 or 2 on 40m on the QMX.

I would greatly appreciate assistance to find the issue.? Thanks!

Hi Bruce,
From memory my Sweeps look similar to yours for 40m.
You speak about the loud noise on 40m when compared to other bands, whilst you may not use 60m does it have the same noise on rx?
Given the sweep look OK, maybe you have a different issue that is allowing "noise" from elsewhere in the radio to bleed into the RX chain.

73,
Warren.

I have a scope, but I'm not sure what I'm doing with it. I did measure some voltages in RX and TX mode of that mosfet. I have attached a photo showing those.

Can anyone confirm, does my RF sweep above confirm the caps c40x and the torroid L401b are good and working?? Seems to me from reading if either of those were wrong for 40m I would notice it on a bad 40m RF sweep?

To begin with the QMX+ was working great until I couldn't get the battery voltage down underneath the GPS.? So, I started looking for the missing voltage and got my multimeter probe across a couple of pins on the 3.3 board and the lights went out.? So I ordered another board and put it in without success.? I have another board so I'm afraid to stick it in and smoke it.? I do have spares of the boards.? Nothing like having spares.? In the meantime I was checking for the 2032 battery voltage across the holder and there were none.? After further inspection the batter I bought had a ridge on the + side so the upper contact was not making.? I found another one without the ridge and now have battery voltage under the GPS so that issue is fixed but now I need to chase down the problem I created.? Any ideas?

Ed.. AB4IQ

I agree. Stopped using Presets. Has Hans posted on this topic??

Was 20-80 tx and rx - and has been a solid unit for months.

Now 20-80 Receive
80m only transmit.

Terminal software only shows 80m - so it thinks it single band.

Fresh firmware, 1.10, and no other issues.

Anyone seen this before...any tips?

Tom

Bi Ludwig
Thank you for the reply.? The probe is a PP-150 which came with the oscilloscope.? I have used it for a few years.
Its bandwidth (@10:1) is 100 MHz.? The probe compensation allows the square wave calibrator to show a good squarewave with no ringing.
The input impedance is 10Mohm/18.5pF.
It is the output voltages from the ExOR gates and the AND gates that concerns me as the lower the voltage output, the lower the RF output from the BS170's.? The measured RF output is within a few 10ths of a Watt as shown on the puTTY Terminal.? Both measurements decrease at the same rate to 0 @ 6m.
Any help you can give would be appreciated.
Regards
Greg

My statements above only seem to be true on 40m, so I opened a new thread for this.?

I did not experience key click issues with recommended settings on 15m or 20m.? Please see my other thread and assist if you can.

Doug,

Made it up from 2 right angle 2.1mm pin barrel pigtails.

73 Kees K5BCQ

Nice, where did you get that cable?

Ordered on 25 June, in my mailbox today, 1 July! I think that is fantastic fast!
--
73
Karl
KI4ZUQ

I am experiencing something that makes me wonder if the information in the Wiki reflects the current firmware.

Background:
When I start up, measuring on a good meter, I get
7.55 V input
5.0? V Vcc
3.01 V Vdd

The Vdd is too low, obviously, and I have been looking into this.? I have bought a new set of SMPSs, but they apparently have not yet been shipped, so I am still looking at my existing supplies to see if I can find the problem.??

The other way to look at this is the measurements from the microcontroller.



The 3.3 volts is still running linear, certainly because the power supply voltages are off.? If the Vdd volts is being used as a reference voltage (likely), then the measured voltages would be off by? a factor of 3.3/3.1? The supply voltage of 8.1 V is close to (7.55 * 3.3 / 3.1), which is 8.04V.? Similarly, (5V * 3.3/3.1), or 5.32 is close enough to 5.47 to be believable.? I am therefore poking around the 3.3V linear supply.? The output of the 78M33 is 3.9V, but the voltage at the zener is 3.03V, so the diode on the back side of the board is dropping? 0.87 V, vs about .6 volts expected.? I?

My question:

I keep going back to the Wiki, which says:


I get to the PuTTY page, but it seems to be limited to the hardware diagnostic page.

I keep coming back to this statement in the wiki and wondering if a newer version of the firmware has changed this, or if there is something that I am not understanding.? Can someone who has direct knowledge of the firmware comment?? I imagine that is Hans, but I would appreciate input from anyone who has direct knowledge.

Bonus questions:
- What is the criteria for turning on the SMPS and turning off the linear power supply?? ?Specific voltages please.
- How is the Voltage in the 3V3 SMPS section of the diagnostic page calculated.? My guess is that it is some factor multiplied by ADC_3V3.? What is the factor?
- How the heck am I getting a solid 5V on Vcc if the power supplies? are in linear mode?? There is no linear 5V regulator, so I must be on switching mode, and the PWM must be set to a good value to deliver 5.0V, but the diagnostic page is showing that the measured voltage is 5.47 volts.? The controller must know something that it is not displaying on this page.? Maybe??

Thanks,
Mark
W8GU

I have compared these sweeps to the sweeps and they look almost identical to those by Hans in the operating manual.

I have again checked the L401b and c401 thru c404.? Everything looks good there.? I cant understand why 40m has soo much noise and soo little signal.? Any help or thoughts please!?
Thank You!