Date   

Re: Difficulty during alignment - RF output #20m #qcx #problem

Alan G4ZFQ
 

Good explanation. From this it looks like Q6 is bad and Q1-3 are all good.
Ron,

Possibly, but the first post says "The RF Output is non existent (measuring using the built in test equipment "9.2 RF Power"). When I touch the pad at L1"

Which might be due to bad joints on L1, L2, or L3 or even O/C BS170s.

73 Alan G4ZFQ


Re: QCX mini: RF output BNC or SMA #poll-notice

George Korper
 

Hi Hans,
I concede and accept the election results.  The. BNC it is and less inventory. 
Now it will all use a consistent set of jumpers with the amplifier. 
I enjoyed all your videos including your retro sideburns! 
The new MINI looks great in the new enclosure. 
73's
K3GK

On Tue, Aug 11, 2020 at 8:14 AM Hans Summers <hans.summers@...> wrote:
Hi all

On the topic of BNC vs SMA preference for the QCX mini RF connector... I closed the poll since it had been open for a few days and I think everyone had a chance. 

Of the 5,136 members of this group, 118 votes were received (2.3% voter turnout). 

Results:

BNC:  90 votes (76%)
SMA:  28 votes (24%)

So. There you go. Democracy. Two mainstream choices, neither of which may actually represent your views. Only a minority of voters actually bother to vote. Wow. We might almost be voting for the leadership of our country! Hi hi. Except that the result would be a lot closer and then we could spend the next 4 years arguing about it :-) 

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

On Thu, Aug 6, 2020 at 3:44 PM Hans Summers via groups.io <hans.summers=gmail.com@groups.io> wrote:

A new poll has been created:

On the proposed QCX-mini, do you prefer a BNC connector like on QCX, or an SMA connector? 

1. BNC
2. SMA

Vote Now

Do not reply to this message to vote in the poll. You can vote in polls only through the group's website.


Re: Difficulty during alignment - RF output #20m #qcx #problem

Ronald Taylor
 

Good explanation. From this it looks like Q6 is bad and Q1-3 are all good. 

Ron

On Tue, Aug 11, 2020 at 04:16 <W5EGA@...> wrote:
Let me see if I can explain this clearly... for reference I will use the same orientation of the board as depicted in the manual. 

123    123
 \|/       \|/
Q6      Q1 

Q2      Q3
 /|\       /|\
123    123

With regard to Q6 pins left to right:
Pin 1 = 13.5V DC with a drop to 13.4V DC with key down.
Pin 2 = 13.4V DC with a big drop that fluctuates with key down.
Pin 3 = 13.4V DC with a big drop that fluctuates with key down.

With regards to Q1 pins left to right:
Pin 1 = 13.4V DC with big drops that fluctuates with key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 0.0V DC with not change upon key down.

With regards to Q2 pins left to right:
Pin 1 = 0.0V DC with not change upon key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 13.4V DC with big drops that fluctuates with key down.

With regards to Q3 pins left to right:
Pin 1 = 0.0V DC with not change upon key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 13.4V DC with big drops that fluctuates with key down.

I hope i was able to explain this good enough. Please let me know what you think I should try next and THANK YOU for taking time to help me learn and fix this problem!


Re: Firmware upgrade blues - help needed

N3MNT
 

Did you download a the latest driver for your USB programmer.


Re: QCX mini: RF output BNC or SMA #poll-notice

Hans Summers
 

Hi all

On the topic of BNC vs SMA preference for the QCX mini RF connector... I closed the poll since it had been open for a few days and I think everyone had a chance. 

Of the 5,136 members of this group, 118 votes were received (2.3% voter turnout). 

Results:

BNC:  90 votes (76%)
SMA:  28 votes (24%)

So. There you go. Democracy. Two mainstream choices, neither of which may actually represent your views. Only a minority of voters actually bother to vote. Wow. We might almost be voting for the leadership of our country! Hi hi. Except that the result would be a lot closer and then we could spend the next 4 years arguing about it :-) 

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

On Thu, Aug 6, 2020 at 3:44 PM Hans Summers via groups.io <hans.summers=gmail.com@groups.io> wrote:

A new poll has been created:

On the proposed QCX-mini, do you prefer a BNC connector like on QCX, or an SMA connector? 

1. BNC
2. SMA

Vote Now

Do not reply to this message to vote in the poll. You can vote in polls only through the group's website.


QCX-mini discussion from Saturday's ZOOM Q&A session

Hans Summers
 

Hi all

I uploaded a 17-minute segment of the recording of Saturday's ZOOM Q&A session, this segment is about the proposed QCX-mini CW transceiver. I do hate seeing and hearing myself on video but endured the pain regardless... see https://youtu.be/KBd8r2kaklc if interested!

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


Re: Difficulty during alignment - RF output #20m #qcx #problem

W5EGA@...
 

Let me see if I can explain this clearly... for reference I will use the same orientation of the board as depicted in the manual. 

123    123
 \|/       \|/
Q6      Q1 

Q2      Q3
 /|\       /|\
123    123

With regard to Q6 pins left to right:
Pin 1 = 13.5V DC with a drop to 13.4V DC with key down.
Pin 2 = 13.4V DC with a big drop that fluctuates with key down.
Pin 3 = 13.4V DC with a big drop that fluctuates with key down.

With regards to Q1 pins left to right:
Pin 1 = 13.4V DC with big drops that fluctuates with key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 0.0V DC with not change upon key down.

With regards to Q2 pins left to right:
Pin 1 = 0.0V DC with not change upon key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 13.4V DC with big drops that fluctuates with key down.

With regards to Q3 pins left to right:
Pin 1 = 0.0V DC with not change upon key down.
Pin 2 = 0.0V DC with a jump to 2.5V DC upon key down.
Pin 3 = 13.4V DC with big drops that fluctuates with key down.

I hope i was able to explain this good enough. Please let me know what you think I should try next and THANK YOU for taking time to help me learn and fix this problem!


Re: Rotary encoder acting funny #problem

Jerry DiPietro
 

Mine also acted weird when I completed and tested the 20 mtr build.  It was a cold solder joint.  
Jerry K9GD

On Aug 11, 2020, at 7:11 AM, Ben Bangerter, K0IKR via groups.io <bwbangerter@...> wrote:

Darren,

Perhaps the encoder data line is open or shorted?  Check with an ohmmeter and visually inspect the trace, on both the front panel and main board.  Good luck!

73, Ben K0IKR


Re: Rotary encoder acting funny #problem

Ben Bangerter, K0IKR
 

Darren,

Perhaps the encoder data line is open or shorted?  Check with an ohmmeter and visually inspect the trace, on both the front panel and main board.  Good luck!

73, Ben K0IKR


Re: Winding toroids

Ben Bangerter, K0IKR
 

See my post #45634 from last April for an alternative method for winding and mounting the transformer on a QCX or QCX+.  It worked well on my recent QCX+ build.

73, Ben K0IKR


Re: Firmware upgrade blues - help needed

Alan G4ZFQ
 

I have tried using the latest Zadig too, for driver installation, but that didn't help.
Anders,

Did you follow a guide like this? https://learn.sparkfun.com/tutorials/pocket-avr-programmer-hookup-guide/installing-drivers

If not read through, see if it makes sense. Although I just noticed their Zadig link is old, why do people keep old files when a link to the site gets the latest? https://zadig.akeo.ie/

73 Alan G4ZFQ


Firmware upgrade blues - help needed

Anders Landgren
 

So...
I have finally got a wire up the tall tree in our new home. And thought I'd fire up my lovely QXCs. But I also wanted to give them a fresh start by upgrading the firmware. They're currently on 1.00f.

I followed the instructions I found in the group files, using eXtreme Burner, but no luck.
The app cannot find my usbtiny thingy that I got off ebay years ago.

So I ordered a Sparkfun AVR programmer from Digitech. It arrived yesterday and... still no luck :-(

AVRDudess doesn't seem to recognize it either.

I have tried using the latest Zadig too, for driver installation, but that didn't help.

The thing is... I distinctly remember that I was able to upgrade both radios to 1.00f using that ebay programmer years ago.

I've tried for hours reinstalling drivers, different USB cables, inserting the isp connector the other way round, but really don't understand AVR programming and am not sure how to even begin troubleshooting.

Any ideas? Anybody out there who could take an old man by the hand and help him get started? I have a nagging feeling I might miss something obvious...

73
Anders, SM5NNO


Re: using U3S with receiver module for WSPR in IQ mode

fred.g3srf@...
 

Thank you to Bruce and Alan. I'll stick to WSPR for use with the U3S and WSJT-X for other modes.


Re: Difficulty during alignment - RF output #20m #qcx #problem

Alan G4ZFQ
 

I have checked Q4 with the multimeter... it shows 14.6V DC without key down and drops to below half upon keying the radio.
Q6 is the prime suspect. What are the voltages on it? Note I say voltages, there are 3 wires, 3 voltages two conditions RX/TX. 6 voltage readings. If you can tell which is collector, base and emitter it helps understand what is happening.

I also checked Q5 and it showed 0VDC without key down and 13V DC upon keying the radio.
Q5 is not a suspect, Q4 could be. Again to test give all 6 voltages unless you know they are not all needed.

I'm at a loss but I'm not ready to quit. Any other suggestions? What do you think about desoldering L1-L4, re-winding them with fresh wire, and starting again?
Initially Q6 or something associated with it is responsible for the symptoms you report. It is possible L1-3 may be badly soldered but rewinding is not necessary.

73 Alan G4ZFQ


Re: using U3S with receiver module for WSPR in IQ mode

Alan G4ZFQ
 

can anyone say if the IQ facility is available on the WSJT-X software.
No, it may be one day but as far as I know there are no immediate plans to add it.

73 Alan G4ZFQ


Rotary encoder acting funny #problem

Darren KN4WML
 

Here's another one.....   I have my qcx+ built in a different enclosure then what it's built for. Everything  The build went ok, everything powers on like it should. The BPF adjustment was in specs, but the IQ balance, low and high adjustments seem to be really low. The 3 are almost at a low 1 on the adjustment. I know it supposed to be adjusted to the lowest point, but this seems a little to low from what I've seen.   
 That's not the main issue at the moment....
    At first everything was working as it should.. buttons, encoders, screen, on/off switch - now the encoder for tuning, which ever way you turn the dial it's like im turning it to the left (down). I put 3 of them on and it still wants to turn left (down).  I turn it left or right it lowers the frequency. .       

That's a new one for me.... I'v hit another stopping point on this one.   

   Thanks
  Darren
  KN4WML


Re: Mass or weight of QCX 50W Amp #pa

Hans Summers
 

Hi Halden

I just measured one here, without enclosure, but including the two heatsinks: 266g

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

On Tue, Aug 11, 2020 at 8:03 AM HF via groups.io <incorridge=yahoo.com@groups.io> wrote:
What is the mass or weight of the QCX 50W Amp without the enclosure?
Halden VE7UTS


Re: Adapt A Bioenno 24v LiFePO4 Battery To Run The QRPLabs 50 Watt PA?

HF
 

Hi Gregg,
Thanks for your quick reply!  I think I'll try keying a 4-ohm load on my boost converter and see how it handles it.  If it's fine, then I'll try it with the PA.  If not, I may try to buy one of the kind you bought.
Cheers
Halden VE7UTS


Re: Adapt A Bioenno 24v LiFePO4 Battery To Run The QRPLabs 50 Watt PA?

Shirley Dulcey KE1L
 

Bioenno rates the maximum current draw of its batteries at 2X the ampere hour rating continuously, and 4K the rating for up to two seconds. Even the little 3Ah ones should be able to provide enough power, but they're not a great choice because they won't run the 50W amp for long. Run time will be the limiting factor with that type of battery, not peak current. 

That is not true for some other types of batteries. Most varieties of lithium and NiCd are really good at peak current. NiMH isn't quite as good as a function of capacity, but because it has more capacity as NiCd you're still usually good. SLA and alkaline are significantly worse, and standard carbon-zinc batteries are the pits.


On Tue, Aug 11, 2020 at 12:58 AM Gregg Myers <gregg.w7grm@...> wrote:
Hi Halden,

To answer your question about about the sudden high current draw, I have not measured the instantaneous envelope response and it would be a bit difficult for me to measure this because I don't have the proper RF attenuator. However, I have have at least 50 QSOs using this power configuration with the 50w PA and can say I have had no complaints or negative comments on the air. So that is a plus. That is not to say that alternate devices might work just as well or maybe even better. The boost module I have was actually recommended by someone else, and I thought it looked interesting enough (and cheap enough) to give it a go. Since it seems to be working for me, I have not had any reason to look elsewhere. 

So I would not discourage your experimentation with other devices and if you do, please provide feedback - probably most of these DC converters are not so different, but it's good to know which are proven in actual practice, especially with regard to unwanted receiver noise.

At the same time, to summarize my experience, I have no ill effects to report on air, nor any noticed noise on the receiver with my setup. I have a 20A-hr LiPo battery or a deep cycle marine battery at my QTH so I have not needed to explore any weaker battery source for running the converter. Maybe someone else might comment if they have tried other batteries. I do run the QCX at exactly 12v when using the PA such that the input RF is not overdriving the Amp. I think that is good practice for everyone, and dropping your QCX supply down to 12v power with some diodes is quite ok.

Ha, I guess I'm not that much help! 😀

Cheers,
Gregg 
W7GRM

On Mon, Aug 10, 2020 at 10:23 PM HF via groups.io <incorridge=yahoo.com@groups.io> wrote:

Hi Gregg,

I’m thinking about how to power this amplifier and my QCX although I haven’t ordered the amplifier yet.   Your solution looks great!  But I have a concern.  How well does the boost converter respond to the PA’s sudden demand for 5A at key-down?  Have you looked at the RF output envelope shape to assess this?  Or does it work so well that this detail doesn’t really matter?

I’m thinking of using the “250W 10A Step Up DC Boost Converter Constant Current Power Supply LED Module” from ebay because I already have a few of them.  It seems to do about the same thing as the converter you cited.

Right now, my QCX runs on 4 Li-ion 18650 cells from Tenergy.  I use a diode to drop a little voltage at the beginning of the discharge cycle.  The higher voltage gives me a bit more TX power, though it’s so small, it’s probably not discernible at the receive end.

I’m not sure the 2.6 Ah Li-ion batteries are up to the task of providing 7-9A pulses on transmit.  Also, they probably wouldn’t last very long.  So, I’m thinking of using my Miady 6Ah LiFePO4 battery when using the 50W PA.  The guidance on using the PA says to run the QCX at 12V to avoid overdriving the PA.  So, I’d probably put in a diode or 12V LDO regulator to drop the LiFePO4’s voltage down to 12V.

Cheers

Halden VE7UTS


Mass or weight of QCX 50W Amp #pa

HF
 

What is the mass or weight of the QCX 50W Amp without the enclosure?
Halden VE7UTS