Date   

QCX mini silkscreen request

Brent DeWitt
 

Hi Hans,

If it ever comes time to update the mini's silkscreen for other reasons, I's like to suggest adding "CAT" and "PTT" to the edge of the display board.
--
Brent DeWitt, AB1LF
Milford, MA


Re: N1MM+ CAT control with QCX+

Glenn ODonnell
 

Use "Kenwood Slow" in N1MM. Works well for me. TS-480 does not. 

VY 73 de Glenn K3PP 


Re: A power unit for the 50W amp...

Larry Acklin
 

Perfect. I used the same power supply, with the added resistance to the voltage set pot, set mine to 19 45V.
With my QCX+ 40M, I am getting ~45W into the dummy load. 10 sec dead keydown doesn’t even warm the heatsink..

Happy here, and with a little margin in the voltages.  I am not fussy about getting the full output of 50+W

73 es QRO :)

Larry
KB3CUF


Re: 50 watt amp not working

Ronald Taylor
 

Hi Terry. The source pins should be grounded. The gate pins will look like a ground if the bias pot is turned all the way down. The drain leads should not measure 0 ohms to ground whether the transistors are installed or not. Looks like you have a short to ground from the drain lead. If the transistors were installed I’d say look at the mounting hardware to make sure the insulators are  installed correctly. But the photos shows no transistors installed and T2 disconnected on one side. Inspect the board traces under magnification. Seems something is shorted to ground somewhere. These pads are very close together. Possibly a drain pad to source pad short?  

Ron

On Sun, Feb 7, 2021 at 09:04 terry schulz <terry.schulz@...> wrote:
Hi, I have a question are all three pins suppose to be connected to the ground in some way? because these are and q2 is smoking on startup also have a
big voltage drop at startup on the power supply hoping someone else has had the same problem Thanks terry


Re: OCX mini IC9 defect? #help #opamp #qcxmini

Jelle
 

Hi PA1DMG, thank you for you answer. I have collected some more readings around IC9.

Do you also believe I am not to expect any further issues as I have I-Q Bal, Phase Hi & Lo responding?

Many thanks, Jelle


Re: OCX mini IC9 defect? #help #opamp #qcxmini

Jelle
 

Hi Steven, thank you for you answer. Do you also believe I am not to expect any further issues as I have I-Q Bal, Phase Hi & Lo responding?

Many thanks, Jelle


Re: OCX mini IC9 defect? #help #opamp #qcxmini

Jelle
 

Hi Zdenek, thank you for you answer. Do you also believe I am not to expect any further issues as I have I-Q Bal, Phase Hi & Lo responding?

Many thanks, Jelle


Re: OCX mini IC9 defect? #help #opamp #qcxmini

Zdenek OK2BQN
 

Hi Jelle,
Replace IC9
73
Zdenek


Re: QCX key click/thump

Jakub
 

Hi,

I had the same issue with QCX mini and changing C21 to the same specs helped to some extent. The clicks are barely noticeable. What is interesting clicks go slightly louder after some time. Maybe it’s because  I used what I had at hand, so I may be looking for something of a better quality. 


73
Jakub


Re: Attenuator Recommendation

Ham Radio
 

For those so inclined, below is BASIC program that you might find useful.  Any floating point BASIC program should work. You can make up your own Voltage versus Power table this way.

10 REM CONVERT VOLTS TO POWER IN WATTS FOR ANY LOAD                                  
20 REM WRITTEN BY B. MURPHY FEB 17, 2020                                        
30 PRINT                                                                        
40 PRINT "ENTER IMPEDANCE IN OHMS";                                             
50 INPUT Z                                                                      
60 PRINT "ENTER RMS VOLTAGE START RANGE";                                       
70 INPUT S                                                                      
80 PRINT "ENTER RMS VOLTAGE END RANGE";                                         
90 INPUT E                                                                      
100 PRINT "ENTER RMS VOLTAGE INCREMENT";                                        
110 INPUT I                                                                     
120 PRINT                                                                       
130 LET V=S                                                                     
140 LET P=V*V/Z                                                                 
150 LET K=V*2*1.414                                                             
160 PRINT "RMS VOLTS",V,"  PP VOLTS",K,"POWER",P,"WATTS"                        
170 LET V=V+I                                                                   
180 IF V<=E GOTO 140                                                            
190 PRINT                                                                       
200 PRINT "ANOTHER RUN (0=NO, 1=YES)";                                          
210 INPUT R$                                                                    
220 IF R$="1" GOTO 30                                                                                                               
230 PRINT                                                                       
240 PRINT "ALL DONE. BYE BYE"                                                   
250 END 
--
73, Bernie, VE3FWF
(most typos in this message have been generated by highly sophisticated auto-correction software)


Re: QCX mini power problem #building

Jan Brink
 

Thanks to Marc PA1DMG I have been able to narrow down the problem to IC6 and 7 . These two are running hot so probably faulty  when I apply power (5V). With R244 (bridge 0 ohms) disconnected the display is working. So without SMD soldering skills and tools what's next ?


Re: Ultimate 3S #u3s

Rob Giuliano
 

Thanks Halden.  Good information.

A potential product improvement would be for the CPU to control the bias through a digital potentiometer, with per-band settings in the firmware.  But I'd prefer that Hans spend his time on his almost-introduced kits than to add such a feature to this one.
I've often thought you could control the bias with a PWM out as a analog output. 
Have a set frequency for the PWM PIN and filter, then store the duty cycle per band to get the needed bias. Maybe even a voltage divider to keep it in a better range for resolution.
I've never done this on a transistor (or MOSFET).
Then the bias number in EEPROM would just be a byte per band for the PWM value of 100 / 255.


Re: OCX mini IC9 defect? #help #opamp #qcxmini

Jelle
 

Some more information around IC9.

I toke to following readings:

Location Example int DVM Comment Vmax Vmin Vavr Vpp Vrms
+ supply terminal 11.98 11.98 As I already mentioned: a 12V supply
IC8 pin 7 2.48 2.52 IC8b output
IC8 pin 8 11.67 11.93
R35 Top x 4.58 4.86 4.66 4.66 0.20 4.66
R35 Bottom x 0.04 Photo 01 8.51 -0.08 2.83 8.51 4.13
R34 Left x ? photo 02 10.70 0.16 4.05 10.54 5.51
R34 Right x ? photo 03 10.46 0.16 4.21 10.22 5.59
C19 left x 0.04 photo 04 8.51 -0.08 2.75 8.51 4.05
C19 Right x ? photo 05 10.38 0.16 4.13 10.22 5,51
C20 left x ? photo 06 10.38 0.16 4.21 10.14 5.59
C20 right x 2.54 photo 07 2.59 2.43 2.51 0.08 2.51
IC9 pin 1 4.84 ? IC9a output earlier photos 10.79 0.16 4.05 10.62 5.51
IC9 pin 2 4.84 ? 10.70 0.16 4.05 10.54 5.51
IC9 pin 3 0.65 0.04 8.51 -0.8 2.83 8.59 4.13
IC9 pin 4 0.00 0.00
IC9 pin 5 0.67 0.35 2.43 2.27 2.35 0.08 2.53
IC9 pin 6 2.44 2.52 2.59 2.43 2.51 0.08 2.51
IC9 pin 7 2.44 2.52 IC9b output 2.59 2.43 2.51 0.08 2.51
IC9 pin 8 11.67 11.93 11.60 11.43 11.52 0.16 11.52
IC10 pin 1 5.83 x IC10a output
IC10 pin 2 5.83 x
IC10 pin 3 5.83 x
IC10 pin 4 0.00 x
IC10 pin 5 4.21 5.20 > 4.31
IC10 pin 6 3.94 ?
IC10 pin 7 5.83 ? IC10b output
IC10 pin 8 11.67 11.93

Here I took the reading from the manual (the example column) and the readings from the internal DVM (x is not taken, ? changing values). I copied the comments or I added the references to photos attached. The following columns are the values from the DSO0138mini scope (cheap scope).

Top, bottom, left, right are orientations looking on the component side of the board (that was the plan).

In circuit resistance of R34 is 10k15.

Does confirm Stevens suggestion I think. Anyone else how likes to comment?

Many thanks, Jelle


Re: QLG1: Great Customer Service #qlg1 #clock #gps

Art Olson
 

Glenn

I had the same issue vcc pin on the rf module was shorted to ground. I didn’t think to let Hans know so I just ordered an assembled one yesterday. 

Oh well, this was only my first kit from Hans that had a problem. I have built several with no issue over the years without any problem. Just the luck of the draw I guess

Art
N2AJO 


On Feb 7, 2021, at 9:25 AM, Glenn ODonnell <k3pp@...> wrote:

It's ALIVE!
 
I want to thank Hans for making his cool kits but also for fabulous customer service! I assembled my QLG1 GPS unit and it didn't work. I narrowed it down to the SMD module - a dead short between VCC and GND on the module. I verified it by popping off the module and testing it. 
 
Hans quickly got another one to me. It arrived earlier this week and I finally got time to apply solder yesterday. It works! I wired it up to my QRP Labs clock and voila! 
 
Woo hoo!! 🎉🎶😎
 
VY 73 de Glenn K3PP
<B8407C80-4E7D-4DA9-B6D0-1FF587053AAB.jpeg>


50 watt amp not working

terry schulz
 

Hi, I have a question are all three pins suppose to be connected to the ground in some way? because these are and q2 is smoking on startup also have a
big voltage drop at startup on the power supply hoping someone else has had the same problem Thanks terry


Re: 20m QCX+ for sale

g4edg
 

Now sold. 


Re: Attenuator Recommendation

Ham Radio
 

Of course. 
--
73, Bernie, VE3FWF
(most typos in this message have been generated by highly sophisticated auto-correction software)


Re: QCX for 2m VHF? #mods #vhf #qcx #chat

KEN G4APB
 

Hi Dick,
there is supplier called Transverters-store on ebay that sell a 2m to 10m board. I bought one for 4m and managed to fit it in a box a little bigger than the qcx- mini. The preamp should easily overcome the loss of sensitivity of the qcx, and the transverter only needs 25mw to drive it, so i bought the attenuator board too but you probably could leave out the finals in the qcx to achieve this.
Just a thought.
Ken g4apb 


Re: #u3s #troubleshooting No Spots / not sure transmitting #u3s #troubleshooting #help #lpf

Roger Hill
 

Hi Alan:

I have been wasting time too, trying to write a small program to pull down large amounts of data from the website. Running into difficulty with passing the parameters to get what I want. So fiddling around to pass a boring Sunday morning in lockdown.
Roger

---
***************************
Roger Hill
***************************

On 2021-02-07 10:53, Alan G4ZFQ wrote:
Roger,
I've been wasting time, attached some charts with different presentations.
All data derived from spots I made.
It does not seem too easy to show something representing the usage of
the 200Hz segments.
For 20m Population I split the spots into 10Hz chunks and plotted. It
struck me that locally any 24/7 stations could skew results.
100 is 1500Hz, centre of the WSPR segment.
20m uniques covers 2 weeks, one spot per station. The number for each
Hz was calculated here
https://www.browserling.com/tools/word-frequency
The centre heavily populated and sub-peaks. Maybe there is a subtle
logic to the way frequencies are selected?
The 60m plot was fewer samples, again showing clumps and gaps where I
made no spots in 2 weeks.
The 20m waterfall shows the last 90 minutes, about 250 spots. Not
setup particularly well.
Of course it is unknown how significant frequency collisions are.
They probably rarely make much difference but it would be best to
avoid the centre area on busy bands.
73 Alan G4ZFQ


Re: #u3s #troubleshooting No Spots / not sure transmitting #u3s #troubleshooting #help #lpf

Alan G4ZFQ
 

Roger,

I've been wasting time, attached some charts with different presentations.
All data derived from spots I made.
It does not seem too easy to show something representing the usage of the 200Hz segments.

For 20m Population I split the spots into 10Hz chunks and plotted. It struck me that locally any 24/7 stations could skew results.
100 is 1500Hz, centre of the WSPR segment.

20m uniques covers 2 weeks, one spot per station. The number for each Hz was calculated here https://www.browserling.com/tools/word-frequency
The centre heavily populated and sub-peaks. Maybe there is a subtle logic to the way frequencies are selected?

The 60m plot was fewer samples, again showing clumps and gaps where I made no spots in 2 weeks.

The 20m waterfall shows the last 90 minutes, about 250 spots. Not setup particularly well.

Of course it is unknown how significant frequency collisions are.
They probably rarely make much difference but it would be best to avoid the centre area on busy bands.

73 Alan G4ZFQ

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