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Re: Select Button on Alignment QCX+ 20m

@CurtisM
 

Richard

also check the solder where this path connects with the microcontroller - few of us complete a QCX+ without missing one solder joint at least partially (for me it was a connection to the highpass pot).  glad you are almost there - look and check carefully - and enjoy the wonderful alignment experience. 

73 curt


Re: QSX+ on 10m or even 6m?

geoff M0ORE
 

Another typo??

On 07/09/2020 15:52, Dean Smith wrote:
Anyone managed it? or are there limitations ie LO frequency, deafness ect?


Re: Select Button on Alignment QCX+ 20m

Alan G4ZFQ
 

I have checked R44 and R45 and searched the whole board for any bad
Richard,

Check voltages on pin 25 of the 328 when pressing the buttons. Button presses give different voltages.
I'm not sure but they should be mentioned somewhere in the manual.

73 Alan G4ZFQ


Re: Select Button on Alignment QCX+ 20m

Gary Bernard
 

I had the same problem, turned out it was a cold joint on the button.


-----Original Message-----
From: Richard M0AUW <cotswoldgent@...>
To: QRPLabs@groups.io
Sent: Mon, Sep 7, 2020 11:11 am
Subject: [QRPLabs] Select Button on Alignment QCX+ 20m

I’ve Just completed my 20m QCX+, it booted up fine showing 20m in the LCD, but when I went to press the select button to get Preset nothing happens. The LCD is working and showing the correct freq and when pressing the other buttons, I get a reaction. So, it seems to be just the select button. If the LCD is working could it be a problem with the 328 microcontroller?
I have checked R44 and R45 and searched the whole board for any bad solder joints, especially the button joints, all seems OK. Any ideas?
 
Many thanks Richard M0AUW


Select Button on Alignment QCX+ 20m

Richard M0AUW
 

I’ve Just completed my 20m QCX+, it booted up fine showing 20m in the LCD, but when I went to press the select button to get Preset nothing happens. The LCD is working and showing the correct freq and when pressing the other buttons, I get a reaction. So, it seems to be just the select button. If the LCD is working could it be a problem with the 328 microcontroller?

I have checked R44 and R45 and searched the whole board for any bad solder joints, especially the button joints, all seems OK. Any ideas?

 

Many thanks Richard M0AUW


Re: Unknown component board

KN6HGG
 

Yep, boost or buck converter with adjustable voltage+current, and a high wattage one judging by the inductor size. Most likely boost converter, but the easiest way to find out is to hook it up and use a multimeter!


Re: Alignment Troubles #qcx #20m #alignment #bpf

Ronald Taylor
 

Connor, 
"Added a 104 cap where C5 goes, and the BPF moved to an "8" and stayed there. Did not change at all in reaction to trimmer setting with the extra cap in place." - 

A 104 capacitor is 0.1 uF or 100,000 pF. Putting that across a 30 pF (max) trimmer in a circuit meant to be tuned to 14 MHz will drop the resonant frequency of that circuit to about 240 KHz. And the little 30 pF trimmer will have no additional effect on that much capacitance no matter where you set it.

Make sure that when you measured for T1 winding continuity across C1, you didn't measure between the two outside pins of the trimmer. These are connected together and will indicate 0 ohms. Measure between one of the outside pins and the center one. Better yet, just measure across the new 104 that you added. Or the open pads for C6 would work as well. In this way, you are looking for continuity through the large winding of T1. I still don't think you have it.

I'm glad you were able to do the 3 null adjustments and you got to 8 on the BPF but the BPF is not tuned at this point and will not be an effective bandpass filter, so if you want it to be correct, remove the 104 capacitor, find this issue with the large winding on T1 and tune it up. If it receives well as is and doesn't suffer from interference from broadcast stations, then enjoy it as is... Your choice ... Good luck ...Ron


On Mon, Sep 7, 2020 at 12:03 AM <connor.mike7986@...> wrote:
Just re-checked across C1, 0ohms. 
Added a 104 cap where C5 goes, and the BPF moved to an "8" and stayed there. Did not change at all in reaction to trimmer setting with the extra cap in place.
Remelted the solder on the volume pot and double checked connections, so it is fully connected now if it was not before(I didn't check this one prior). Afterwards was able to at least to set the 3 nulls to their minimums.
I will need to wait till the band gets more traffic in the morning to see if I can receive anything.

Connor, W7AOE


Re: Unknown component board

Bruce K1FFX
 


Re: Unknown component board

jjpurdum
 

Pretty sure it's a step-down buck converter.

Jack, W8TEE

On Monday, September 7, 2020, 12:29:11 PM EDT, K2DB Paul Mackanos <paul.mackanos@...> wrote:


Does anybody have any idea what this is, I ordered two of them at one point in time, can’t remember what it was, or what it is for.

Just wondering if anybody can tell me what it is, and how to adjust it because there are two Multiple turn pots on it ?

I’m going to guess a DC voltage buck or boost converter.

Paul K2DB


Re: Unknown component board

Gregg Myers
 

On Mon, Sep 7, 2020 at 10:29 AM K2DB Paul Mackanos <paul.mackanos@...> wrote:
Does anybody have any idea what this is, I ordered two of them at one point in time, can’t remember what it was, or what it is for.

Just wondering if anybody can tell me what it is, and how to adjust it because there are two Multiple turn pots on it ?

I’m going to guess a DC voltage buck or boost converter.

Paul K2DB


Unknown component board

K2DB Paul Mackanos
 

Does anybody have any idea what this is, I ordered two of them at one point in time, can’t remember what it was, or what it is for.

Just wondering if anybody can tell me what it is, and how to adjust it because there are two Multiple turn pots on it ?

I’m going to guess a DC voltage buck or boost converter.

Paul K2DB


Re: 80 meter bpf toroid winding 30 turns givel 4.3 micro Henrys, not 3.8

Arv Evans
 

As mentioned earlier by someone else,  compressing or spreading 
the turns on a toroid core probably does not change the inductance
very much (the number of turns remains the same).  What it does 
do is to change the distributed capacitance between turns.  

Also mentioned by others is that the apparent inductance of metallic 
cores does change with frequency.  This could be a factor if you are 
operating the core at widely different frequencies.

DC loading also causes toroidal cores to change apparent 
inductance.  While probably not an issue with DC isolated 
filters, it could be problematic for tank circuits that carry DC
current.

Arv
_._



On Mon, Sep 7, 2020 at 8:56 AM Kees T <windy10605@...> wrote:
KI7MWA,

If xx turns of #28 wire do not allow moving the turns around a little, try #30 wire.

73 Kees K5BCQ


Re: 80 meter bpf toroid winding 30 turns givel 4.3 micro Henrys, not 3.8

KI7MWA
 

I thank all for the advice.  Clearly I've f***ed this up, so I've ordered another kit and I'm tossing this one.


Re: QCX+ T1 Toroid Wire Length? #20m #qcx+ #20m #toroid

Syd
 

   I suspect that when winding T1, if you get the primary or the BPF winds wound in the wrong sense, it will have no effect with the circuit. The only windings that must have the right sense are the 180 degree, out of phase , windings into the quad detector! The input winding sense of the transformer has nothing to do with the secondary winding sense, and the BPF winding works alone, so it's sense doesn't matter either.  Only the quad inputs do matter, so they better have the same sense, no matter what the other windings have. 
   That's why I make the large winding first, then install T1, and then add in the other windings, one by one, by soldering the start, winding the turns, and then solder in the end of the winding. It's real easy to get the sense right, all you have to do is look at the input lead of the large winding and see how it was wound into the toroid and do the same for all the other windings and the sense will be correct.  I find this much easier than doing the whole shebang and then trying to figure out what goes where.


Re: QSX+ on 10m or even 6m?

Dean Smith
 

Oh no... , that'll have people running for their keyboards, sorry :[
i meant QCX. 6M sounds interesting, i thought it would be just out of reach.
10m would be achievable with usual firmware i take it?
Just when you think your mind is made up..,now i'm not so sure,


Re: QSX+ on 10m or even 6m?

ajparent1/KB1GMX
 

from playing here...

QCX..  10, 6M seriously need RF preamp on RX.  Adequately sensitive for lower HF
but higher bands rquires a 10 or more DB lower MDS.

2M, didn't bother the general scheme is not suited for 2M use.  Minimally
needs a preamp.  Then LO and mixers issues.

I didn't bother with transmitter as while BS170s are good at 2M they are not going to 
run class E even at 10M.

Having done many radios for 6,2 and above hacking a ACX for that is the hard
way to go and the amount of CW activity is thin mostly contesting.  FT8 is the
big thing how.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: QSX+ on 10m or even 6m?

Hans Summers
 

Hi Dean

You mean QCX+ not QSX+ :-)

As you go up in frequency, receiver sensitivity and transmit output power go down. 

6m does not work. It requires a tweak in the firmware, which I have done in a beta version I run here but which is not yet released. In the beta version, 6m does work, a couple of people have tried it. I can't quantify the degradation in receiver sensitivity. Transmitter output power was reported in the range 1-2W. 

73 Hans G0UPL
http://qrp-labs.com

On Mon, Sep 7, 2020 at 5:52 PM Dean Smith <bardezbiker@...> wrote:
Anyone managed it? or are there limitations ie LO frequency, deafness ect?


Re: 80 meter bpf toroid winding 30 turns givel 4.3 micro Henrys, not 3.8

Kees T
 

KI7MWA,

If xx turns of #28 wire do not allow moving the turns around a little, try #30 wire.

73 Kees K5BCQ


QSX+ on 10m or even 6m?

Dean Smith
 

Anyone managed it? or are there limitations ie LO frequency, deafness ect?


Re: Clock/TMP36 Connect

Phil
 

Thanks Brian! I was just trying to figure that out. Good timing!

Phil

On Sep 7, 2020, at 7:44 AM, BrianB <brianb@...> wrote:

Phil,

If you are going to display the temperature in Fahrenheit the following settings will get you a good starting point.

Temp1 CAL 0C = 066
Temp1 CAL 25C = 094

73,
BrianB
N6CVO

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