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Re: QCX+ Pin Headers

N3MNT
 

They will fit fine.  I use headers on as many connections to the board as possible.  For the CAT control and GPS connections to the rear panel in the QCXPI added headers to the board end of the connections.  Much easier to install and work on the board as the header can be unplugged. 


QCX+ Pin Headers

K2DB Paul Mackanos
 

When i got to this step:
3.54 Install header pin connectors JP3, JP4 and JP5 

Lo and behold, no pin header in kit, (sigh). I knew if i contacted Hans, he would send me another, but the wait time is too long when you get to this point in the building of the kit. I went to DigiKey, and found them, already cut to the size needed, Very inexpensive, so I ordered a few extras. Ordered them on Wednesday, they arrived on Friday. Now to go and install them in the mostly completed kit, and continue. I hope they fit :-)
Just and FYI for you guys.
Paul K2DB
image.png


Re: QCX+ not working ….HELP!!!

m0bmn
 

Its Finished! working 100%
After a long time tracing and fault finding i had two problems, the first was a problem with TXCO module, Hans is sending me a replacement, due to  that i spent days going through each section measuring voltages looking at wave forms etc etc. re soldering just about ever part in case of dry joints etc , the process had one casualty, the volume control, those of you  that have built the new QCX+ will know the volume control pins just dont reach the board and that you have to use a blob of solder to bridge the gap. Well since i was having problems with signals not getting through on the receiver path i must have resoldered the volume control a number of times, it must have melted the connection inside the pot as the middle pin was Open circuit, i replaced it but with a temp one as the shaft is to short, anyway i now have a fully working 100% QCX+ all the problems i have had have stemmed from  the TXCO and the assumption it was working and believing it must have been something else. Thats all history now and the QCX is alive (just waiting for the new volume control too)
i have done A/B comparisons between the Shack yaesu rig and this and i can honestly say you would not copy a signal on the yaesu that the QCX could not copy too. very  impressed, now to build the amplifier for it.
A Big Thank you to Hans and ALL the great people here on the forum who without  my QCX would be in land fill by now.
i can see i will have some fun with this!
73 and thanks again all.
Paul M0BMN 
off to build the amp!.... stay tuned folks


Re: Help needed to update QCX firmware #firmware #qcx

N3MNT
 

When using Avrdudess the first thing you should do is click the detect button.  If the uP is not detected nothing else will work. 


Re: Help needed to update QCX firmware #firmware #qcx

Ben Bangerter, K0IKR
 

Another word of thanks to Simon for his writeup on reflashing the ATmega328P in the QCX.  I flashed my QCX from T1.00b to T1.05 yesterday using my “original” Arduino clone.  Initially I tried and failed to communicate with the QCX processor with either that Arduino or a Nano clone.  Then I suspected that it might be a connection problem, as the “Dupont” jumpers I was using did not seem to fit very tightly on the ISP header pins of the QCX.  Jumpers from another set I had were a tighter fit, and that solved the problem.  I still was not successful using the Nano however.  The faulty jumpers are on their way back to Amazon!

73,  Ben  K0IKR


Re: QCX+ not working ….HELP!!!

Knut Steinar Fremme OE4KSF
 

Nice to see you got it working :-)

Most of the time - it's an small error - and often in soldering - to cold solder, solder not flowing , to mush solder etc etc.

Start fra what you know are working and work your way out from that.

But have to say that the voltage list from Hans is a very good list to follow. From that you wherry often can find in what part of the board you need to inspect more.  

Knut


Re: QCX+ not working ….HELP!!!

m0bmn
 

Hi Ron / All
I have a simple scope and I have looked at the waveforms as shown in the guide , all look good but i can only see one output at a time (single channel Scope)  to check the phase you need to compare both waveforms (I/Q)
I will take another look this morning and see if i can find whats wrong, its surprising how well it works even without adjustment.
report back later, i feel we are getting there...
73 Paul M0BMN


Re: 10 Watt linear with T-R switch?

ajparent1/KB1GMX
 

Alan,

I am aware of that.  I have a softrock RXTX ensamble.

Allison
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Re: QCX+ not working ….HELP!!!

Ronald Taylor
 

Paul, just continue to follow the troubleshooting procedure. The problem is most likely in the phase shifting circuits. The procedure shows the waveforms to be expected at different locations. You are almost there. Don’t stop yet. Good luck. 

Ron

On Sat, Jul 18, 2020 at 16:10 m0bmn via groups.io <m0bmn=yahoo.co.uk@groups.io> wrote:
Oh Happy Day. Thanks for the help Knut
after a number of pokes and head scratching i followed advice and put a 330 ohm resistor across R49, this allowed me to hear the alignment tone and to trace it though the rx chain, i vanished to ground around R26, after close inspecting i found one end was down to ground and so shorting out the signal, i un-soldered and re soldered the resistor and the short was gone! i removed the extra resistor and turned it on this time i could peak the bandpass up to about 9 which is good and the tone was clear as a bell. i connected a antenna and music to my ears CW!
i tuned around and compared it to my main station yaesu, if the yaesu can hear it so can the QCX, great , and tx seems fine to, i have side tone !
Still a problem but to be honest the QCX seems fine as it is.
I can  peak the band pass but the I/Q balance and the other alignment settings just dont seem to make any difference , i have adjusted the trimmers from one end to the other and the reading just sits there the same, i adjusted the volume to read about 8 to start with and thats where it sat at all settings of the trimmer,
the radio is now very usable but it would be nice to get it set 100% although i cant believe it would be better in performance, there is a few calling test tonight and their signals are all about the same  (and on the same freq) as my FTDX1200.
anyone ideas  why i cant adjust the other settings?
take care and thanks to all for the support and comments.
Paul


Re: QCX+ not working ….HELP!!!

m0bmn
 

Oh Happy Day. Thanks for the help Knut
after a number of pokes and head scratching i followed advice and put a 330 ohm resistor across R49, this allowed me to hear the alignment tone and to trace it though the rx chain, i vanished to ground around R26, after close inspecting i found one end was down to ground and so shorting out the signal, i un-soldered and re soldered the resistor and the short was gone! i removed the extra resistor and turned it on this time i could peak the bandpass up to about 9 which is good and the tone was clear as a bell. i connected a antenna and music to my ears CW!
i tuned around and compared it to my main station yaesu, if the yaesu can hear it so can the QCX, great , and tx seems fine to, i have side tone !
Still a problem but to be honest the QCX seems fine as it is.
I can  peak the band pass but the I/Q balance and the other alignment settings just dont seem to make any difference , i have adjusted the trimmers from one end to the other and the reading just sits there the same, i adjusted the volume to read about 8 to start with and thats where it sat at all settings of the trimmer,
the radio is now very usable but it would be nice to get it set 100% although i cant believe it would be better in performance, there is a few calling test tonight and their signals are all about the same  (and on the same freq) as my FTDX1200.
anyone ideas  why i cant adjust the other settings?
take care and thanks to all for the support and comments.
Paul


Re: QCX+ not working ….HELP!!!

George Korper
 

Put it in the closet for a while. 


On Sat, Jul 18, 2020, 2:53 PM Knut Steinar Fremme OE4KSF <steinar@...> wrote:
One thing more - try to lift the Q7 out of the board , but first measure the voltages ....
Knut 


Re: QCX+ not working ….HELP!!!

Knut Steinar Fremme OE4KSF
 

One thing more - try to lift the Q7 out of the board , but first measure the voltages ....
Knut 


Re: QCX+ not working ….HELP!!!

Knut Steinar Fremme OE4KSF
 

Somewhat good, as the side tone is generated , I would follow that part first - as you do not hear the tone.
Did you measure the working conditions for IC 8,9 and 10? do you have about same voltage on input and output of ll of them?

Like IC8 - pin 5 and 7, IC8 pin 3 and 1 and so on ?  If this is not so - the IC can not work.

And use you scope and check if you have any tone on IC-8 pin 7 and 1 - and go backward from there - follow the whole path into IC-10 pin 3 and 1
If you do not see any sort of tone - in any of the outputs from one of the IC - we work from there .

There will be a frequency change from 42KHz into 700Hz on the route - but look for anything - that is changing when you key your TX   

I would concentrate on this LF part first, and then look into the RF part later.

You write that you have LF into the speaker when you inject a tone somewhere - where did you inject the LF ? and at what level do you inject the LF - do you know about ?

But check the voltage first now - and we go from there 

Don't give up - we will help you -and remember most are working - CPU and TX  only a little glitch on the RX part - :-)

Knut


Re: QCX+ not working ….HELP!!!

Jim Mcilroy
 

Hi

When I check transformer windings I select pads on the PCB that are connected to the transformer and put an meter on those. If I get continuity I know the joints at the transformer pads are OK.

On 18/07/2020 16:49, m0bmn via groups.io wrote:
Thanks for the email, i have checked on the solder pads under the board, but will go and check again anyway, i wish it could be as simple as that. 
Many thanks for your time
Paul M0BMN 


FS: New QCX 30/40 kit + new BaMaTech enclosure #qcx #30m #40m #case

Roger Reeves M0ROJ
 

For sale as new and unopened QCX kit with both 30m and 40m LPF's, together with as new unopened BaMaTech enclosure kit.
All in mint condx. Selling at below cost - GBP80. + postage. Will accept PayPal or bank transfer.
Roger M0ROJ

QRP Labs QCX 30m/40m kit


BaMaTech_Enclosure


Re: 10 Watt linear with T-R switch?

Alan G4ZFQ
 

A tr switch is needed and also input attenuator as even the softrock
exceeds the needed drive of 20-40mW.
Allison,

Indeed it should! As mentioned by Hans it uses the same driver stage, the Softrock is normally 0.5-1 or more watts depending on voltage.

73 Alan G4ZFQ


Re: 10 Watt linear with T-R switch?

ajparent1/KB1GMX
 

Curt,
Its not an enhanced bitx amp... not even close, save for the same IRF510s.
The differences are VHF layout vs long wires and leads for openers.  Add
adequate heat sinking and better drivers.  Result near flat performance
from 1mhz well beyond 30mhz.  The uBitx even the latest struggles to do
4W at 28mhz, push it harder it gets unhappy.  I did a lot of work on it
trying to improve ubitx amp!  Better, see the wiki there its a lot of my time.

A tr switch is needed and also input attenuator as even the softrock
exceeds the needed drive of 20-40mW.

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


Re: QCX+ not working ….HELP!!!

John Pagett
 

The 42kHz is right for the sidetone. It was a later mod. From memory Hans alters the PWM of the 42kHz at sidetone frequency. After passing through a suitable LPF it gives the 700Hz.
Originally it was a 700Hz tone and the PWM was used to alter the sidetone amplitude but the DC shift on the average was a problem.

John
G4YTJ


Re: QCX+ not working ….HELP!!!

Ronald Taylor
 

Paul, in order for your scope to see the signals in the front end of the receiver circuit, you need to follow the suggestions in Hans' troubleshooting procedure https://qrp-labs.com/qcx/qcxtrouble.html, where he suggests paralleling a 330 ohm resistor across R43 to greatly increase the level of the test signal. Then he shows details on what should be seen at what points. If you follow that procedure, you should be able to determine if the problem is indeed with IC4 or not. I didn't see any mention of following that procedure in the postings. 

Best 73 ... Ron


Re: QCX+ not working ….HELP!!!

m0bmn
 

Thanks for the email, i have checked on the solder pads under the board, but will go and check again anyway, i wish it could be as simple as that. 
Many thanks for your time
Paul M0BMN