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No 700 Hz tone
robert cox
Hi -? 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... Thanks in advance for your help.
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Re: T1 on QCX 40
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
开云体育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:
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Re: ZL1RS balloon flight - BB01
开云体育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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Re: T1 on QCX 40
开云体育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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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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Re: QCX audio crackle
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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Re: QCX Manual
Hew Lines
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.
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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 On 2017-12-07 6:55 PM, Keith VE7GDH wrote:
Hew VA7HU wrote...About 6 of us in the local club are building the 20MMine are for 80M and 40M, so I won't have a QCX there, |
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Re: QCX Troubleshooting - Please can you help?
Arv Evans
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. |
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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?
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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check your resistor value
Hi,
Building the U3s with 5w amp, no rf output so stripped the amp out of system and base U3s works. The 5w amp biased up ok but still no output so I checked the resistor placement with a Dvm, R2 is 15k and feeds the base and collector of Q3 and base of Q4, R19 is also 15k, both resistors have identical colour bands, however, one, R2 measures 10k! There are no 10k resistors in this kit.? End result is a blown Q3. Andy |
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New Year's Eve Operation
开云体育Dear QRPLabs Members, ? In my last message I invited all QRSS and WSPR stations to join the Las Cruces QRSS Mafia to operate with us on New Year’s Eve.?? Well, today is December 9th and we have about 21 days left to get our stuff ready to operate from 0000Z 31 December to 2400 1 January 2018.?? It is 48 hours and the purpose is to Celebrate the forward movement of the Amateur Radio QRSS Operation by filling all the Grabber stations with signals.?? The more signals the better.? Don’t worry about stepping on each other a little bit.? Just get a signal in there wherever you can.?? Mother Nature’s Propagation will scramble it even worse, so it won’t really matter.??? Some collisions of signals at one grabber will not be perceivable at another.? So in the end it doesn’t matter.?? What really matters is that you got on the air and you contributed to the massive whiteout of the grabber.? There is a way for the WSPR crowd to join us by programming their U3S’s to do both WSPR and the rest of the 10 minute give QRSS some time with another 2 DFCW QRSS signal and still put a WSPR transmission out every 10 Minutes.??? So get your program manual out and try something new.? We would also love to see you call sign on our screens. ? My contribution this year as a multi-band grabber in New Mexico.? It is presently operating on 30M and 40M? 24/7 in the test mode.? (I may have to take it down for some additional tweaks to improve its operation) but for the most part it will be up. Between now and New Year’s Eve, I plan to add 80M and 20M to it and have them operational.? The Website is ?and this is my test bed for building an all Amateur Radio Band Grabber for 2200M through 10M grabber at This location? by next New Year’s Eve.? Each grabber band consists of a QRPLabs QCX transceiver operating as a receiver, a raspberry pi 3B operating as a spectrum analyzer, and a usb sound card of the inexpensive variety.? It is working well and I am learning lots of new things about it as I keep peeling the onion.? But the one thing I do know for sure.? An inexpensive quality QRSS grabber is within reach for anyone who wants to experiment with these units.? ? If anyone would like to know more about my “experiment” let me know.?? Go to the website and look at my grabs.? Start planning your own setup.? ? Take care and have fun.?? See you on New Year’s Eve.? Get your ?QRSS TRANSMITTERS ready to go on the air.? New Year’s Eve will be here before you know it.? (In case you have forgotten, New Year’s Eve comes right after that jolly old man called Santa Claus or Saint Nicholas or whatever he is called in your country,? and right after New Year’s day come the credit card bills for all the new radio equipment you bought. ) ? Take care and have fun.? Hope to see you on my new Grabber.? QRSS is a BLAST, even at mW’s Merry Christmas, 73 Dave Hassall WA5DJJ? Las Cruces, New Mexico Website: http://www.zianet.com/dhassall/ ? |
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Re: ZL1RS balloon flight - BB01
Would be quite interested in the info too
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John On 12/9/2017 7:54 AM, Don Meyerhoff wrote:
Very cool Bob. If you have some info on it I would like to work on something similar with my kid to get her interested in the hobby. --
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Antonio Fernandez EA4LE
M0RON