Re: QCX Challenge tomorrow
#qcx
I was QRV for one hour at 13:00Z
Worst propagation ever ... I could only hear 2 or 3 stations on the whole CW segment on 20m (and those were probably big gun DX'ers)
Not much better on 40m, only could work OK2BQN, with a very weak 419 signal ... tnx Zdenek !?
I'll be back at 19:00 on 40m.
Remember : there is a CHAT page for the QCX Challenge, to increase your chance of finding other QCX users, or being found.
For those that use it, it would be nice if you could add a picture to your profile.
73,
Luc ON7DQ?
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Re: QCX-mini enclosure, update 25-Sep-2020
Oh, this unit is something very special. I can't wait to get one and take it up to a SOTA summit!
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Re: Low Power fix on QCX 80 and a sugestion for a possible addition to QCX test gear to measure inductance.
Hi Des
Thank you for documenting your results.? I found them to be very useful.??
When a good friend recently sent me a Version 2 QCX 80 kit to build, and being aware of this discussion, I decided to use your results as a starting point.? Accordingly, I wound as follows:
L1: 20 turns
L2: 23 turns
L3: 20 turns
L4: 22 turns
(In the case of L4, I went for 22 turns as a compromise between your results and the details given in the manual!)?
Anyway, with a supply of 13.5 volts, I got just over 4 watts out on 80 m.? This power output was initially measured on a Welz SP220 power meter, and confirmed by measuring Vpeak across a 50 dummy load with a Kenwood CS-6040 oscilloscope.? ?I was very happy with this result, and made no further changes.
Thank you, Des, for your contribution.
Best wishes, Steve
?
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all went as expected. tracking number shows it got stuck somewhere along the way. Hans is aware.
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Re: QRP Labs #dummy load at 0dBm
#dummy
?
Hi Ben,
Where are you measuring your 30V peak with?
Please find enclosed table for Voltages and power: I used it for making a QRP Watt meter, it goes down to 1mW 50 Ohm 0dBm
10 Watts 40dBm -40dB is 0dBm, I suspect your VNA used as a spectrum analyser is not the best way to measure power, S21 is a through measurement, and S11 is a reflected measurement, how are you getting both on screen at the same time? I presume your directional coupler is internal to the VNA, was the cal set up?
?
?
73’蝉
?
Andrew
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Re: QCX Challenge tomorrow
#qcx
-- I will have my QCX+ on 7030 +/- a few kc's for the last session from 0300-0400 unfortunately this is the only time that is feasible for me to get on. 73 all
Rick w9rea
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Re: QCX Challenge tomorrow
#qcx
Hi Steve
Thanks for trying and thanks for the report; nice to know who was?trying! I did copy the odd character here or there but nowhere?near?a whole callsign. I don't think my antenna does as well on 20m as on 40m. Actually I had my QRP Labs 20m receiver module on WSPR earlier and it wasn't copying much there either. Much less than usual.?
I worked only one station on 20m, R6UAJ.?
73 Hans G0UPL
Hi
No so much activity, but worked the following on 20m
SM7RYR?
SV5/HB9FIH
F5MDY
E72TR
And sadly TA4/G0UPL right at the end that just failed to copy me...you were a nice 539 Hans.
Using my new QCX+ at 5w to a 3 element triband yagi at 10m.
72 Steve G4EDG
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Re: QCX Challenge tomorrow
#qcx
Hi
No so much activity, but worked the following on 20m
SM7RYR?
SV5/HB9FIH
F5MDY
E72TR
And sadly TA4/G0UPL right at the end that just failed to copy me...you were a nice 539 Hans.
Using my new QCX+ at 5w to a 3 element triband yagi at 10m.
72 Steve G4EDG
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Victor,
I put mine inside with the U3S and the patch antenna on the outside. This makes a compact unit and has worked flawlessly for me.
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Victor
Try an experiment before you mount it there. Your own data will provide the answer, but a patch antenna like this is designed for nearly hemispheric coverage. Of course it should be mounted with standoffs.
I prefer the ability to place this gps unit away from other objects, so I have it in a separate plastic container.
Shalom. Enjoy the blessings of your faith holiday events just now.
Curt wb8yyy
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Kofi
To email the qrplabs owner, click on Shop. There is a link there to Contact him.
Curt
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Not sure what you are looking for, but QRP-Labs is a small business and really doesn't have representatives or sales offices.? Hans' staff consists of himself and two employees that work out of his home.? That said his products are above amazing in design and performance for the cost.? This group offers excellent before and after sale support and Hans is here almost daily.
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Re: QCX Challenge tomorrow
#qcx
40M at 1300 and 20M at 1900.
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Re: QCX Challenge tomorrow
#qcx
I will be there on 20 at 13:00 UTC
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Hi all.
Does anyone know of a?QRPLabs representative in Africa?
Kofi
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Hi,
I am assembling a U3S system, and using the QRP Labs enclosure. I
have built the QLG1 and tested it. In my location it achieves a fix
in less than a minute on my workbench.
I am wondering if there will be a problem if I mount the QLG1 on top
of the U3S enclosure (on the outside). I'm guessing that the
enclosure will shield it well enough from the transmitter.
Has anyone done this with good (or bad) results?
--
73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
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Re: Advice wanted: QCX-mini capacitor microphonics
Hi Hans,
Do what ever gives good performance Vs. cost index.
This change is for a QCX mini not a QCX ultimate edition, keep
that one aside......
The "Golden Ears" can always source their own film capacitors to
scratch that itch.
KISS
On 27/09/2020 10:23, Hans Summers
wrote:
toggle quoted message
Show quoted text
Hi all
Progress... brief report:?
I didn't find any blu-tac but the kids have a
lot of play-doh so I was able to apply some "putty"-like stuff
for damping and as far as i could hear, it seemed to make no
difference.?
My current thinking is that using through-hole
capacitors for the sensitive SMD caps will be the right
solution as long as there is space. Cheap and effective. I'd
prefer not to have to use film or tantalum capacitor types
which could bring other problems, are more expensive and
increase logistical and production complexity and cost.
"Prefer"... as in, it's an option but hopefully a last resort
I won't need to use.
I replaced the four QSD capacitors with their
leaded counterparts and the microphony decreased markedly; i
replaced two more capacitors and got more improvement.?
It is also my impression that the through-hole
capacitors, which contain a 0603 SMD capacitor soldered to two
wires, and dipped in a yellow blob of something... are less
microphonic than their un-encapsulated raw SMD counterpart,
not just due to being on wires. But also because the yellow
blob provides a lot of vibration insulation.?
I then came to the opinion that there were too
many "seemed" and "impressions" and not enough hard numbers so
I have set up a test jig to hopefully be able to make
repeatable and quantitative tests to solve this problem.?
I have put back all the original SMD capacitors
to restore the QCX-mini 20m prototype to its original state
with the microphony. Now I can move forward and hopefully make
proper numerically informed decisions about the effectiveness
of various remedies and replacements.?
I hope to have completed analysis within a day
or two and will report back in full.
73 Hans G0UPL?
?
On Sun, Sep 27, 2020, 11:51
Mike Bowthorpe < mike@...>
wrote:
My only
comment is to speak to an acoustic engineer.
They may have a solution?
Mike
G0CVZ
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Re: QCX-mini update, 24-Sep-2020
Hello Halden
My apologies, that's my typo. The op-amp I am using is OPA2277 (not 2272).?
73 Hans G0UPL
Hi Hans
I built my QCX with sockets for those opamps so I could swap them for other types to save power.? But I never did.? I can't find OPA2272 on the internet.? Is it the same as TLC2272?
Cheers
Halden VE7UTS
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ON7DQ Luc
Michael N6QP
Steve Rawlings
Lloyd K3ESE
Andrew Lenton
BrianB
N3MNT
Kofi & Mimi in Ghana
Victor 4X6GP
Alan de G1FXB