Date   
Re: Which manual do I use?

Simon Kennedy
 

Some would say that you were being too hasty in not waiting until you received the kit but as yours has been shipped from the US you will get it quicker than if it had been shipped from Turkey, so small mercies etc!

You need to look at Section 10 Document Revision History, p145.

I really don't think you've got any reason to reprint the manual if you get a Rev 4 board. You will have an additional capacitor to install (C39) but that's all.


On Thu, 9 Jan 2020, 22:52 Leland L. Bahr, <w5drc@...> wrote:

Your comments  have nothing to do with my concerns or tell me something I do not know.

Lee, w0vt

On 1/9/2020 4:50 PM, N3MNT wrote:
Most people build from assy instructions on a laptop or tablet.  The board rev should be on the board you receive.  If it was shipped from the US warehouse, you should have it in a matter of days.  These are the changes so no need to reprint entire manual.

Re: Which manual do I use?

ajparent1/KB1GMX
 

Myself I'd hold printing till I see it but, the REV5 is the shipped unit.

Do review the web page as there is both history and dates outlined
as well as what changes each rev adds.

The reason you got a suggestion to work from the screen over paper
is any changes or fixes (including documentation) are often incorporated
very quickly to the on line sources.

 I've built a few bits of QRPL gear and the web page is the reference
not here.  Though we have a lot of good people here that have built
them as well.  I really like the QCX I have.

Allison
-------------------------------
Please reply on list so we can share.
No direct email, it goes to bit bucket due address harvesting in groups.IO

Re: Which manual do I use?

Leland L. Bahr
 

Your comments  have nothing to do with my concerns or tell me something I do not know.

Lee, w0vt

On 1/9/2020 4:50 PM, N3MNT wrote:
Most people build from assy instructions on a laptop or tablet.  The board rev should be on the board you receive.  If it was shipped from the US warehouse, you should have it in a matter of days.  These are the changes so no need to reprint entire manual.

Re: Which manual do I use?

N3MNT
 

Most people build from assy instructions on a laptop or tablet.  The board rev should be on the board you receive.  If it was shipped from the US warehouse, you should have it in a matter of days.  These are the changes so no need to reprint entire manual.

Which manual do I use?

Leland L. Bahr
 

I decided to buy another QCX-40.  I live in the US.  I ordered the radio on Jan 1.  I downloaded REV-5 Manual Jan 7.  I got a shipment notice the radio was shipped from the US on Jan 8.  No shipping info nor any serial number given.  Just that it was shipped from the US.  I recently read QCX boards were out of stock and not expected to be available again until the middle of January.  So that is what I know.  My concern is which manual do I use to build the radio once it gets here?  Will I get a Rev-4 or Rev-5 board?   I would hate to think I need to throw away the Rev-5 manual and have to reprint 9 zillion pages for a Rev-4 manual for a radio I have not yet received.  If I had known about all this, I would not have printed out the BIG Rev-5 manual and had it bound until I knew which manual to download.  Personally I think communications are poor!
Lee, w0vt

Re: 4 line display for qrplabs clock

Roy Edens
 

Thanks to all who responded to my request on 4 line display .

Re: Anyone have a dead QCX with a good receiver?

Andrea Massucco IZ1IVA
 

Nevermind, it's now stopped booting altogether.

I've first tried Hans' recommended fix (moving L5) but that didn't work, then snapped one leg of L5 without having a spare one. After much cursing I hoped G3JRH's fix could save the day (I have a small supply of Schottky diodes), but no.

Either my QCX is haunted or my solder is ageing causing issues around the circuits. I really can't think of other plausible reasons for these behaviour and I'm starting to think it'll be far easier for me to assemble a new QCX than troubleshooting this one.
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net

Re: QCX 50 Watt PA what is the max current for 50 watts.

harleyleenuke
 

Allison,
I assumed by reading the IFR510 specs.  that I should add about 85 ma.  

 I re-performed the adjautment last night with about the same results.  
 

That got me thinking.  I have the qcx powered with 12 volts.  The qcx is putting out about 2 watts.   I adjust the qcx voltage up to 13 volts.The power out was 3 1/4 watts.
 I then connected the PA and my output was about 45 watts.

I was just following Hans suggested setup,  placing the qcx at 12 volts.   

With the PA attenuator envolved,  That must really knock the QCX down alot.  So maybe the amp is working ok.
 If I modify the attenuator for 2 watts input from the qcx @ 12 volts, then that may correct the issue





Re: 4 line display for qrplabs clock

N3MNT
 

I used this and works great. 
https://www.amazon.com/gp/product/B00GZ6GK7A/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Re: Anyone have a dead QCX with a good receiver?

Alan G4ZFQ
 

The alignment tone is strong enough to pierce whatever roadblock there is, not so real radio signals.
Andrea,

But I was thinking if the radio was 30dB down then 30dB lower tones might be noticed. But I have never tried.. Some form of signal tracing might help, a scope or diode probe. I think troubleshooting suggests a lower value for R43 for the early stages.

Late 2017, but it developed this issue only very recently.
A dry joint can take a while to show up.

73 Alan G4ZFQ

Re: Anyone have a dead QCX with a good receiver?

Andrea Massucco IZ1IVA
 

Il giorno 09 gen 2020, alle ore 16:56, Alan G4ZFQ <alan4alan@...> ha scritto:

Are they really as strong as described in the manual?
They definitely are.

The tone signal is fed into the input of the LPF, there is not much between that and the antenna socket.
True, but there are many stages after that HI! I’d say the core of the receiver, the many op-amps, etc. Lots and lots of components and solder joints…
The alignment tone is strong enough to pierce whatever roadblock there is, not so real radio signals.

How old is it? This sort of fault was rectified very early in the life of the QCX. Look at the mods page, maybe something is faulty on one of the pins that power the micro.
Late 2017, but it developed this issue only very recently.

Cheers
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net



--
-- 73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net

Re: Anyone have a dead QCX with a good receiver?

Jim Manley
 

Many thousands sold per year ... just wait until the QSX hits the street ... the total number of views for the QSX page is now over 1.1 MILLION!!!  OK, that's not views by unique visitors, and half of the views have probably been by me because I check the page every time someone mistypes QSX in a post/message, to make sure I didn't miss an announcement, but, still ... 


Jim  KJ7JHE
Lame Deer High School Amateur Radio Club  KJ7JKU


On Wed, Jan 8, 2020 at 9:52 AM ajparent1/KB1GMX <kb1gmx@...> wrote:

From what I know literally many thousands are sold per year.  Last announcement last year
the number of units crossed 8000.  Unlikely to be in the same lot.

Re: Anyone have a dead QCX with a good receiver?

Alan G4ZFQ
 

I wonder what would happen if it were faulty, open or short circuit, what would be the symptoms? I'm not an expert but I think either way all that would happen is that the filter would not be so effective.
In my case I can barely hear signals which in reality are pretty strong, and that’s with maxed-out gain… and a quiet room HI!
Andrea,
I would not think that C17 would do that but maybe I'm wrong.

I did A-B comparisons with another radio and the same antenna, I’d say signals are down a good 30+ dB. On the other hand, alignment tones are loud and clear.
Are they really as strong as described in the manual? The tone signal is fed into the input of the LPF, there is not much between that and the antenna socket.

My QCX was working perfectly before, only recently has developed this fault, plus the microcontroller isn’t starting anymore when first powered on (cold boot). I’m really puzzled!
How old is it? This sort of fault was rectified very early in the life of the QCX. Look at the mods page, maybe something is faulty on one of the pins that power the micro.

73 Alan G4ZFQ

Re: Anyone have a dead QCX with a good receiver?

Andrea Massucco IZ1IVA
 

Il giorno 09 gen 2020, alle ore 11:53, Alan G4ZFQ <alan4alan@...> ha scritto:

I agree, however Vern wrote he had to replace C17 in both his faulty QCXs… it could be a coincidence, but what are the odds of that?
One could ask why no-one else has reported that problem?
That’s true Alan, I’m not even trying to draw conclusions based on a sound statistical basis. However, I found it interesting that Vern found exactly the same faulty component on two QCXs and I was wondering if that could help me fixing mine.

I wonder what would happen if it were faulty, open or short circuit, what would be the symptoms? I'm not an expert but I think either way all that would happen is that the filter would not be so effective.
In my case I can barely hear signals which in reality are pretty strong, and that’s with maxed-out gain… and a quiet room HI!
I did A-B comparisons with another radio and the same antenna, I’d say signals are down a good 30+ dB. On the other hand, alignment tones are loud and clear.

My QCX was working perfectly before, only recently has developed this fault, plus the microcontroller isn’t starting anymore when first powered on (cold boot). I’m really puzzled!
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net



--
-- 73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net

Re: 4 line display for qrplabs clock

jjpurdum
 

Ron, Jim:

Terry King has a bunch of Arduino-related stuff as well as displays:



While not the cheapest, he has lots of info about what he sells and sample code you can use to experiment with. His 20x4 displays are about $10, but support the I2C interface so they use fewer I/O pins. Plenty of info on it if you're not sure about I2C (which is supported by the Arduino family of processors).

While perhaps not the cheapest stuff on the planet, you'll be supporting someone who stands behind what they sell and genuinely wants to be helpful.

Jack, W8TEE




On Wednesday, January 8, 2020, 11:02:27 PM EST, Ron NR8O <ron.rollinson@...> wrote:


Jim,

If you have the time, you can get these pretty inexpensively out of China. I've ordered a couple and they work and look great. Do a search for '20x4 lcd module'. You can sort by price, low to high, or even specify if you want to buy from a seller in the U.S.

73,
Ron NR8O

Re: general coverge rx on qsx

Ed Kwik
 

A tuner like this one will act as a band pass filter.
Ed
AB8DF

Re: Anyone have a dead QCX with a good receiver?

Alan G4ZFQ
 

I agree, however Vern wrote he had to replace C17 in both his faulty QCXs… it could be a coincidence, but what are the odds of that?
One could ask why no-one else has reported that problem?
I wonder what would happen if it were faulty, open or short circuit, what would be the symptoms? I'm not an expert but I think either way all that would happen is that the filter would not be so effective.

73 Alan G4ZFQ

Re: Anyone have a dead QCX with a good receiver?

Andrea Massucco IZ1IVA
 

Il giorno 08 gen 2020, alle ore 17:52, ajparent1/KB1GMX <kb1gmx@...> ha scritto:

I'd consider it unlikely that your weakened RX is C17. Likely other failures are
to be investigated.
I agree, however Vern wrote he had to replace C17 in both his faulty QCXs… it could be a coincidence, but what are the odds of that?

Oddly the first place I'd go is soldering.
Yep, I’m reflowing a few pins at a time, but I still haven’t fixed it.

Thanks
--
73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net



--
-- 73 de Andrea IZ1IVA - cq at iz1iva . net - http://iz1iva.net

Re: general coverge rx on qsx

Erik Kaashoek
 

The ATU comes in various designs. L-C-L or C-L-C and they either act as a low pass filter (when the C go to ground) or a high pass filter (when the L go to ground) but never as a narrow BPF
But your antenna is a (multi) BPF!!!!
Using a half size g5rv and the QRP-Labs receiver I am able to receive FT8 (in the middle of a city) from literally  ALL over the world on 40m and 20m.
The half size g5rv only needs a little bit of tuning. see attached measurement. Maybe if I shorten the dipole it could get even a bit better.


When using my 1 Watt transmitter on the half size G5RV I have a switchable low pass filter for 20m and 30m/40m and that is all I use. No BPF for FT8 as the antenna is already a good BPF!!

--
Erik, PD0EK

Re: Multi Band QCX and the BPF/LPF switching

Hans Summers
 

Hi JP

Typically at the higher frequency end, preamplifiers start becoming necessary/desirable. I don't think this is related to switching out the BPF. I don't have any specific recommendations at this point. 

The QCX has no real spare I/O pins but I did find a way of using the CD D6 and D7 pins as output pins. They can be set using the CAT command AX. For example AX2; will set D7 high and D6 low. D7 and D6 are mapped to the two least significant bits. So AXn; where n is a number from 0 to 3, is the command used to control these two bits. They will suffer microsecond-scale glitches whenever the LCD is updated so whatever you are controlling with it needs to take this into account. Relays are too slow to care about those microseconds. 

72 Hans G0UPL 


On Thu, Jan 9, 2020, 09:15 J P Watters via Groups.Io <kc9kko=mac.com@groups.io> wrote:
Hans,

Thanks again for your contributions. I have the parts to assemble a 10 or 11 band relay boards to switch out the BPFs and LPFs  that are appropriate for the band selected. One of the comments on removing the BPF or switching it indicate that some signal amplification would be needed to make it a sensitive multi-band QCX. 

Do you have a recommendation of what amplification circuitry to use to improve the signal levels. 

Additionally i think that the your email of December 16th indicated that there are two spare i/o pins on the QCX. I would like to use those to switch in and out the CW filter to enable SSB. What would be the CAT command to set the output levels of the spare i/o pins on the QCX. Can you please identify the I/O pins you had identified as really spare?

Thanks again,

..jpw J P Watters
KC9KKO