Good day all; ? To Hans, just a suggestion for an enhancement. I found manually calibrating the reference crystal a bit cumbersome having to set the frequency, jump out of the menu, transmit a signal then back into the menu to readjust.? Yes I know the GPS unit is a plug-n-play and is real easy to set.? Since I didn’t have the GPS unit had to set it manually. I was able to get it close.
My suggested enhancement would place the rig into transmit upon entering that menu option and apply the change of the reference frequency. This way it can simply be aligned against the reference source by simply dialing in.?
Not sure if it can be done but would be a great enhancement for a great little rig.
72; Kurt -W2MW?
Get
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Re: Annual QRSS New Year's Eve Party
Hi Dave
I have not tried this mode. Do you have a list of all the recommended QRSS frequencies and speeds or a link to them please. I might try reprogramming my multiband U3S if I have the details.
73 Ken G4APB
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Re: ZL1RS balloon flight - BB01
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Hi All,
I mounted the board in a case I picked up at a fleamarket and have been enjoying listening to the QCX this weekend.? (some kind of Italian CW contest this weekend...)? I am really impressed with the receiver performance.? One issue I have noticed is that when a very strong station (i.e. S9+++) comes on frequency I have to tear the earphones off.?
I found the "AGC" for Bitx circuit but was wondering if some kind of clamping of very strong signals could be achieved with a zener diode between pins 6 and 7 of IC10B.? Ideas / comments would be welcome.?
As may be seen from the output waveform (0.5V/div and X10 probe into a 50 ohm dummy load) photo I still need to do some work on the LPF toroids.? My initial probing around showed almost 3 dB drop across the LPF - in spite of great care taken to wind the toroids to design value (AADE L/C meter).? ?Moving the windings around with a plastic alignment tool does not change power output noticeably.? Next time I take the box apart I will see if I can find one toroid that is attenuating more that the others and adjust the windings on that.? ?Meanwhile I logged good reports from UA4 and 9A5 so 2.25 W is workable.? My CW skills were much better 40 years ago? :)
Great kit - very enjoyable build.
73
Earl, 4Z4TJ
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Re: QCX Troubleshooting - Please can you help?
Arv
This is not correct.?
The AVcc pin provides power to the internal analogue voltage circuits in the ATmega328.?
The QCX uses the ATmega328 ADC with the reference set to the supply voltage (AVcc). Not the internal reference.?
73 Hans G0UPL
On Sat, Dec 9, 2017 at 9:45 PM, Arv Evans <arvid.evans@...> wrote: AVCC should be very close to the Vcc supply voltage.? If that is at 4.6 then either your Vcc is at
4.6 or something is dragging AVCC down.? Normally this pin is unconnected, but if you want
best repeat measurements from the ADC you can add a filter to the AVCC lead.
ADC reference for analog-to-digital voltage conversions is the built in 1.2 volt AREF potential.
If the AREF is not correct then the ADC measurements will be inaccurate.
If using ADC inputs to detect specific voltages you can use a high impedance DC meter
to measure the actual voltage to see if they are within a range specified by the software.
Arv
_._
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Hi -?
I have a 20 meter kit and I started the alignment procedure and I noticed that I can peak 8.7 by adjusting the capacitor C1 but then when I try adjusting R27, R24 and R17 I am always at the minimum. After some troubleshooting I put my headphones on and noticed that I am not getting the 700 Hz tone.
I checked the frequency out of the Si5351 in normal mode and CLK0 gives 14.0213 MHz and CLK1 is 14.0214 MHz. I don't know if these are the proper values or not. I've also tested the Si5351 in "Test Equipment" mode using the signal generator and the frequency counter (connecting a wire from FREQ to CLK0 as described in the manual) and it seems to work properly.
The voltage inputs on IC5 (pins 3, 2 & 5, 6) are slightly different than what is shown on page 125 of the assembly manual even taking into account my higher supply voltage:
I don't know if these voltages are a problem or not...
Lastly, I did wind T1 improperly the first time, but I removed and re-wound it and it looks correct now.
What else can I check??
Thanks in advance for your help.
73,
-Rob (N4MN)?
??
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Hi Glen,
I get the feeling that T1 is fairly tolerant. I've done 4, 4, 4, 31 windings instead of 3, 3, 3, 30 -- in a guestimate attempt to make the RX work on both 20m and 30m (but I cannot check this as yet until there is a firmware update as something else prevents 20m being received when 30m band has been selected).
I find the audio range from min to maximum is quite good and the RX is very sensitive, on a par with big rigs. What you have done may have helped reduce the volume a bit, who knows. Great she is working well, and that the number of turns on T1 is not too critical it would seem, looking at the charts near the end of the manual you can see the BPF is quite broad.
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Re: QCX audio crackle is still there!
GM Barry,
I've 30m QCX without that problem. I built mine with T1 a little different 3, 3, 3, 31 windings instead of 4, 4, 4, 30 windings, but the audio range is fine and sensitivity on a par with the big rig. C1 is not fully open nor closed, so the peak test is OK. For the dip test (I think that was side band rejection) I have to go to one extreme with the variable resistors, but again I seem to have no problem with hearing any opposite side band. I assume you have gone through the alignment menu section of the manual again and ensured you have correct peaks and dips. When I first read that I did not understand the importance of the digit top right, and that had me confused.
Hope you can find the cause and fix the problem.
I'm using 1.00(b).
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Re: ZL1RS balloon flight - BB01
Thanks for the info Dave ... as you say, not so cheap.?
So far the ECS TCXO on BB01 has been OK ... I can see some 'steps'
occasionally,? but the WSPR and JT9 still seems to decode.? The next
one will try the Chinese TCXO (cost about $1).
73, Bob? ZL1RS
On 9/12/2017 10:44 PM, David wrote:
toggle quoted message
Show quoted text
Bob,
I've used a 'Connor Winfield D75F-027.0M' ? TCXO in two U3Ss as
it has an analogue feedback loop - avoiding jumps.? Suggested by
another poster on the group some months ago.
I haven't done any tests but the original poster was using one
in a 10GHz Rx setup after finding issues with the Fox unit.? Not
cheap though.
73
Dave
G3WUN
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Re: ZL1RS balloon flight - BB01
oops, I just tested something here locally and screwed up the
tracking map.? Perhaps Hans can fix that?
Looks like BB01 got hit with ice loading(?) yesterday.? There was a
sharp drop in the temperature before it descended.? The last signal
yesterday was probably when it went below the clouds in the area NE
of Wellington, New Zealand (as seen on satellite weather imagery).?
Once lower to the ground the warmer conditions apparently melted the
ice and BB01 continued to fly.? It woke up after sun rise the next
day once there was sufficient sun angle on the solar cells, and by
this time it was about 1500km SE of New Zealand over the southern
Pacific ocean.? The signal was starting and stopping indicating it
must be in partial clouds, but more recently it has transmitted
steadily and the high solar voltage indicates that it is in bright
sunshine again.
73, Bob? ZL1RS
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Re: New Year's Eve Operation
Dave,
I'll give it a try!? Am I correct, each symbol is 6 seconds? Sorry, this is all very new to me!
ATM, the message line I use for a CW ID at the end of my WSPR transmission and my message line is "#CS". I take it we need to program several DFCW QRSS segments all on the same frequency in order to get any kind of repetition.?
I guess my question is this: If I understand correctly, would it be better to:?
1. Program my message as something like: callsign<space>callsign<space>callsign<space>...etc. with less Tx'd segments but drop the CW-ID segment,
2. Keep the #CS, maybe add a space, and add more Tx'd segments,
3. Just type out the callsign<space?>, add more Tx segments and keep the CW-ID segment?
Thanks!!
--Al
WD4AH
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Hi Glenn,
T1 is in the Rx chain only, so the TX will not be affected at all.?
Fewer turns on T1 will not be ideal for the RX, but won't stop it
from 'working'.? They are not tuned, just a transformer action to
couple the antenna to the tuned circuit (large winding) and get the
phasing required for the input to IC4.? However, the QCX RX might
even be better with the correct number of turns for the three small
windings.
73, Bob? ZL1RS
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Just found out by reading QCX mail that I have wound the three small winding's on T1 with only 3 turns instead of 5 per the instructions! However rig is putting out 4 watts and receiver is great! WHY? Glen N8WE
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Re: QCX audio crackle is still there!
Just in case anyone stumbles over this.? I recently had to replace the QCX Atmega chip; this after bricking the original.? I've since learned how to update the chips properly. Initially I thought that audio crackle had been solved with the new chip and firmware, but it has not.
The audio crackle is like hearing lightening strikes while listening to HF DX. I can hear CW and WSPR tones but, really, the crackle is so harsh it makes using the 30 metre QCX? unpleasant.
So, I';m open for suggestions as to how to resolve the issue.
I'm using a 12 volt, fully charged battery, to drive the radio.
Thanks
Barry
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Keith... I sure apologize for taking this long to respond.? After you mentioned Earl's web page, I had a look and simply sent him a note.? He had the parts to me in jig time!? In fact I recently needed a couple of 1/2 watt resistors... he happened to be coming in to Sudbury, so I met up with him and made the exchange.? That web page is huge.
Thanks for that suggestion.
Barry
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Not sure why they picked the 20M version. I plan to use the 20M in the trailer when we are camping (often). We spent a week on Salt Spring this summer and enjoyed it so much we will be back again this year. I plan on using a "Buddie Pole" with the 20M QCX and see how it works out.
I'm going to put the rig in a Hammond project box that has a sloping front panel and will be mounting the LCD, pots and switches on the front panel (aluminum) and all the jacks on the front and back panels (plastic).
I use some "play dough" that i get at the dollar store to hold the small components for soldering and it seems to work well for me. I have used small pieces of masking tape before but the play dough seems to work better. Rick VE7TK is also building one and he has a lot of experience with winding toroids so we are going to have him give as a quick presentation when we get to that point. Should be a fun project and I am going to take lots of pictures !!
Hope you have a Merry Christmas and all the best in 2018. Will keep you advised how things are going.
73 - Hew
toggle quoted message
Show quoted text
On 2017-12-07 6:55 PM, Keith VE7GDH wrote: Hew VA7HU wrote...
About 6 of us in the local club are building the 20M
version as a club project. Mine are for 80M and 40M, so I won't have a QCX there,
but I could dial my "big rig" down to 5W. We might be
a bit close for 20M though. Of course, that's assuming
you can send slow enough for me!
Just a suggestion... I found it tricky soldering the
single pin headers in place. If I was doing it again,
I would probably install them right at the beginning
when they weren't surrounded by other parts. Sticking
the pin in some dense foam might be a way of holding
it upright while putting the PCB down over the pin to
solder it.
I put the male pin header on the LCD display instead
of the female connector (a la BITX) so I soldered the
female connector on the QCX board. The stand-offs are
a bit long. You would think I would have learned from
the first one, but if there's a third, I'll sand about
1 mm off the stand-offs before adding the LCD display.
That way, the header can just be pushed flush down
onto the LCD display for soldering. With the stand-offs
a bit long, I ended up pushing the pins a bit further
through the plastic part of the header, so the short
pins made it only just to the top of the LCD circuit.
I used the LCD circuit board to push the male pins
down into the connector and then soldered them.
Good luck with the club project!
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Re: QCX Troubleshooting - Please can you help?
AVCC should be very close to the Vcc supply voltage.? If that is at 4.6 then either your Vcc is at
4.6 or something is dragging AVCC down.? Normally this pin is unconnected, but if you want
best repeat measurements from the ADC you can add a filter to the AVCC lead.
ADC reference for analog-to-digital voltage conversions is the built in 1.2 volt AREF potential.
If the AREF is not correct then the ADC measurements will be inaccurate.
If using ADC inputs to detect specific voltages you can use a high impedance DC meter
to measure the actual voltage to see if they are within a range specified by the software.
Arv
_._
On Sat, Dec 9, 2017 at 10:23 AM, <ondrej.briatka@...> wrote: Problem with encoder - try to check voltage at pin AVCC of ATmega. It should be close to 5V.
After "Unreliable microcontroller start-up" modification, I had only 4,6V on AVCC that caused bad decoding of buttons inputs (3 buttons + resistors make a different voltages on A/D input, software compares it to reference AVCC).
Inductors 100uH has quite high resistance of 7 ohm that means voltage drop on ATmega pins.
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Re: Two-band QCX (20 and 17m), is it possible?
Thanks Alvey, this is very useful info. I was also thinking abt the "preselector" for the front-end ;) glad to learn from Hans that he is willing to modify the software :)?
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Re: Two-band QCX (20 and 17m), is it possible?
I get the point Hans and makes sense. But... tinkerers always pushing the envelope :) I was considering 17 and 20 taking into account the monoband ethos of the QCX because these bands are close. What I do not know is if this "stretch" is within the correct quadrature limits. The idea? would be 20m the primary band and 17m the secondary.
Thanks for producing things like these for us to enjoy!
73? de antonio, EA4LE?
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Re: QCX Troubleshooting - Please can you help?
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Kurt Zimmerman
Earl
Antonio Fernandez EA4LE