Re: QDX TRIFILAR STEP 2.12 Wind and install trifilar toroid T2
I don't think the draft manual is quite clear enough on this.? It is important that the START and FINISH of the windings are identified as well as just continuity.? It would be possible to mix up start and finish of windings and still get a good continuity check!? So make sure that the 3 "starts" are on one side, and the 3 "finishes" on the other before doing your continuity checks!
Total failure if you get this wrong as the phasing won't be right...
--
Peter Lee
G3SPL
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While lying in bed recently, my mind pondered on the QDX and it suddenly struck me that it has no manual controls at all: it is totally controlled by software. This would make it ideal for remote location, for example, in a shed at the bottom of the garden, making antenna arrangements easier and getting somewhat away from the noisy domestic location.
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Next morning, I looked up how far you can run a USB cable: answer, not far enough for my needs, but then I came across the "USB Extender over Cat5 cable".? For somewhere around ?10 or so, you can buy 2 units which you interconnect with cat5 cable up to a distance of 50m - just what the doctor ordered!
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Next, what sort of CAT5 cable to use for installation outside and probably directly buried. It turns out there is suitable outdoor grade cable available with tough double sheath and not too expensive - about ?50 for 100m. Burying the cable in the lawn is desirable for two reasons.? Firstly, it is relatively easy by using a spade to make a slit (about 150mm deep) into which you can push the cable down using a small piece of wood. The grass is then restored by pressing down with your foot. The second reason is that burying the cable gives some screening and also helps common mode rejection due to the capacitance of the cable cores to ground.
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Further reduction of common mode noise from the PC can be achieved by winding the CAT5 cable around a couple of ferrite toroids near the PC end.
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Powering the QDX is most easily done using a 12V lead acid battery which is charged up in the shack and taken down the garden for each operating session.? A suitable sized battery would allow several typical operating sessions between charges. (The QDX would need to be built for 12V operation using a 3:2 ratio output transformer rather than 2:2.)
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What about changing bands?? At first, I thought I would have to use a separate multicore cable to control some antenna switching relays. Then I realized that the QDX has band select signals to control the preselector.? BAND0 and BAND1 are output from the microcontroller to give a two bit binary output, where "00" represents the 80m and "11" represents 20m band.
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It would be relatively easy to take the BAND0 and BAND1 signals from the microcontroller (available at IC3, pins 14 and 2 respectively) and feed them to the gates of a couple of BS170 MOSFETs as relay drivers.? Two relays, one SPCO and the other DPCO can be wired to select one of 4 antennas under these control signals from the QDX. It would probably be best to put a simple RC low pass filter on the MOSFET gates to stop RF from the transmitter affecting the relay operation - that could be disastrous if it caused an incorrect band selection!
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The relays could be configured to select different ATU settings if you use a single antenna. Of course, if you have a multiband antenna you don't need any of this antenna selection arrangement at all.
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So remote operation could be fairly easy to achieve.
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However, for me it will have to remain a dream as I was 30 minutes too late to place a QDX order!
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-- Peter Lee G3SPL
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Hi Fred
More likely, you should have it by Monday. Trust in USPS! I expect you will let us know on Monday :-)?
73 Hans G0UPL
I received my shipping notice email (from US stock) for order 50001 this morning.? So in a week or so I should get the QDX.? Maybe I will be able to build over Thanksgiving... We will see.??
Fred W0FMS/7
On Wed, Oct 27, 2021 at 09:07 AM, Mike KK7ER wrote:
the USPS will notify you of ANY package on its way to you if you sign up for an account
I have been using this service for years.? It not only tells you about packages you are receiving, but provides an image of all normal-sized mail, like mail in the regular-sized envelopes and postcards.? I get an email every morning with these details, so I get to see the junk mail before it hits my mail box!? When there is a foot or two of snow outside, I know in advance if I need to make the trek out to the mail box.? I see I have a USPS package shipped by pirateship and coming from Sedalia, MO.? I have received QRP Labs kits from Sedalia before, so likely have the kit by the weekend.??
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As soon as i switched to the asset tracker sketch that does not need a gps fix to start i got instant connection to helium. here is the cayenne dash board. The pico tracker sketch worked? the first time i tried it the other day but not since. The position is showing on map but altitude is 0.00
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Re: QDX TRIFILAR STEP 2.12 Wind and install trifilar toroid T2
Hee Hee...can you imagine wrapping? in such a way that one wire gets wrapped around
the the other or others in such a manner, at the end of say 10 inches it is close to an?
inch longer than the other and you cut it off to even it up...that is almost a full turn on the toroid.
:}:}:} that would be crazy,,,,never happens.?
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Re: AA Battery Power for QRP Labs gear
Yeah, I¡¯m still sorry I didn¡¯t pick up several of those fire-alarm batteries at my local ReStore when they were only $1 each, they¡¯d be perfect for the QCX I have on order.
Recycling is to raw materials, in the case of these batteries back to lead, is often stupid. The smart way to recycle is to repurpose to a less demanding role. I know I got ticked off a couple of U.S. administrations back when huge sums were spent to crush so-called gas guzzling Ford F-150 pickup trucks. While they might no longer make sense for full-time construction work, they¡¯re ideal for homeowners needing to haul stuff occasionally. When I need concrete or landscaping stones for my place, I have to make multiple trips in my Toyota subcompact, making sure I don¡¯t go over 300 pounds. I could haul far more than that one trip in an old F-150, and for the use I¡¯d give it, the gas mileage matters not.
In much the same fashion, old ham gear can be passed along to new hams. My first ham transmitter in the 1960s cost about $5 as war surplus. It was a marvelously well-built Command set employed in B-17s during WWII and given a new purpose. Actually, I had two, one for 80 and one for 40. I still have the antenna coil from one of them and if my hunch is right the wire in that coil is silver. It¡¯s three-quarters of a century old and still useful.
¡ªMike Perry, WA4MP
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On Oct 28, 2021, at 9:24 am, Chris Wood via groups.io <g4cws@...> wrote:
I use a 12v 7AH battery from our own domestic alarm system. It sits in a box on my desk, charged by a small solar panel, and feeds my QCX family and my FT817. As you say, the security company had to replace it and I couldn't let them junk (at my cost) a potentially useful battery. In fact I have two from that source, one as a spare....
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I received my shipping notice email (from US stock) for order 50001 this morning.? So in a week or so I should get the QDX.? Maybe I will be able to build over Thanksgiving... We will see.??
Fred W0FMS/7
On Wed, Oct 27, 2021 at 09:07 AM, Mike KK7ER wrote:
the USPS will notify you of ANY package on its way to you if you sign up for an account
I have been using this service for years.? It not only tells you about packages you are receiving, but provides an image of all normal-sized mail, like mail in the regular-sized envelopes and postcards.? I get an email every morning with these details, so I get to see the junk mail before it hits my mail box!? When there is a foot or two of snow outside, I know in advance if I need to make the trek out to the mail box.? I see I have a USPS package shipped by pirateship and coming from Sedalia, MO.? I have received QRP Labs kits from Sedalia before, so likely have the kit by the weekend.??
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Re: AA Battery Power for QRP Labs gear
Mike
I use a 12v 7AH battery from our own domestic alarm system.? It sits in a box on my desk, charged by a small solar panel, and feeds my QCX family and my FT817.? As you say, the security company had to replace it and I couldn't let them junk (at my cost) a potentially useful battery.? In fact I have two from that source, one as a spare....
Chris? G4CWS
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Nice idea. But then the QCX-mini is by far the smallest part of the whole setup. This is just an antenna switch. You supply a RX and panoramic display yourself. 73 Alan G4ZFQ
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Re: AA Battery Power for QRP Labs gear
Those looking to save money might contact local companies that service fire alarms and exit lights for public spaces. They typically have to replace the batteries, typically small, sealed, lead-acid ones, after a certain amount of time. The batteries are likely to still have years of life left in them.
I know because a few years back a local charity thrift was selling them for $1 each. Wish I had bought some.
¡ªMike Perry
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On Oct 27, 2021, at 10:57 pm, dwentz <digid2@...> wrote:
To make things even better there are been a bunch of new 5AH cells being given away at the local hamfests by the local QRP club.
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Syd, I just finished a QCX+ (40M) build. I had to remove 7 turns from T1 to get the trimmer capacitor off the fully open position. The BPF (8.7) moved up as I removed turns. I did not bother going through the hole for this, I merely left about 1/4" of wire from the board and soldered the shortened winding to it. I then checked power output and found none, though an adjacent rig could hear it. It turns out L4 had a bad solder connection, easily fixed with a few seconds of soldering iron heat and a dab of flux. I then had .7 watts, so I spread out L3 and got it up to 2.7 watts. That was my clue to remove a couple of turns. Between that and tweaking L1 and L2 (mostly L2) I got it up to roughly 4 watts @ 13.8V. That's less that I'd like, but one more watt would make almost no difference to a receiving station so I quit there.
I have since made a bunch of great contacts.?
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Hi Paul
Nice idea. But then the QCX-mini is by far the smallest part of the whole setup. Can you imagine having a panadapter as a separate?box the size of QCX mini? Like Elecraft's KX3?+ PX3 combo. That would?be really cool!
I know it is a rather ambitious idea, but I could resist it, hi!
Kind regards
Janez, S58J V V ?et., 28. okt. 2021 ob 11:56 je oseba Paul Harrison via <dj0cu= [email protected]> napisala:
This panadaptor looks perfect as an addition to the qcx mini etc.
A description can be seen here:?
And can be purchased on Banggood.com at the moment for around 40 euros.
Paul DJ0CU.
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This panadaptor looks perfect as an addition to the qcx mini etc. A description can be seen here:?https://youtu.be/jKqXBvsrGsI
And can be purchased on Banggood.com at the moment for around 40 euros.
Paul DJ0CU.
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Thanks Paul
I agree, and I have amended the manual accordingly.?
73 Hans G0UPL
On Thu, Oct 28, 2021 at 11:27 AM < paul@...> wrote: On page 17, the text describes the 3:3 option for T1 but the board diagram still references the 3:2 option. This might be slightly confusing. Also, maybe there should be a pointer on this page back to page 4?
Paul
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On page 17, the text describes the 3:3 option for T1 but the board diagram still references the 3:2 option. This might be slightly confusing. Also, maybe there should be a pointer on this page back to page 4?
Paul
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Re: QDX TRIFILAR STEP 2.12 Wind and install trifilar toroid T2
Hi George
Yes, you?are correct... T2 is a very important component.?
I like to wind my toroids as neatly and tightly as possible because it actually does increase the Q and that improves the performance a little sometimes. Every little counts or at least maybe it doesn't really count much, but it does make me feel better which does count hi hi. In the case of transmission line transformers like T2 it's actually not so critical, making tidy uniform twists etc.?
But what IS totally critical is to correctly identify the 6 wires and put them into the correct 6 holes on the PCB... so pay very high attention to all the blurb about DMM continuity measurements.?
73 Hans G0UPL
Hello,
This is a very important step. Hans has advised extreme care.
I suggest following Han's method to a "T'.
Looking over my workmanship in the 50 watt amp. I see I didn't take this seriously enough,
and thought I would mention it before the rush to build the QDX starts.
Mea Culpa warning (hi hi). I have no evidence to prove that sloppy procedure in this regard
results in trouble but bad "twisted pairs" may come back to haunt you.
George
K3GK
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Hello Hew
I was a bit mystified by that... so had to look into it... I do not think you received your QDX. I think you received order?50607 which was two QLG2-SE kits.?
50063 does not appear to have been sent which is a glitch in the QRP Labs team Turkey... I have just gently applied my foot and so they should be shipping it today.?
73 Hans G0UPL
On Thu, Oct 28, 2021 at 4:48 AM Hew Lines < va7hu@...> wrote:
QDX? #50063 just arrived in Nanaimo BC this morning. Shipped 7 days
ago.
73 Hew VA7HU
I am still waiting for my order #50000 shipping confirmation.? I
have the PayPal email confirming payment at 1:02 CST (1802Z).? It
may be that because I ordered more than one for our build club
that the quantity is causing the delay.? All good things take
time, as long as it is not next year ;-)
73
Evan
AC9TU?
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Re: QCX Challenge - October 2021
I tried the 1300 and 1900 slots on 40m with no success. My cq calls did not register on the RBN network. Also my qcx mini rx decoder does not seem to work, I just get random letters even though I can read the signals by ear, are there any special settings needed to make this work?
ken g4apb?
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May I suggest also checking that the CAT polling interval is 10 seconds.?
Rapid polling is not necessary on QDX because there is no way for the QDX to change its frequency by itself. Polling is only really needed for example by a logging program, to find out what frequency etc the operator has changed the radio to. QDX only changes its frequency if the host PC tells it to. Therefore there is no downside to a longer polling interval.?
73 Hans G0UPL
On Thu, Oct 28, 2021 at 9:18 AM KEN G4APB via <lfoofui.nbz42= [email protected]> wrote: Hi Earl,
I have noticed an issue with wsjt-x that no tx audio tones are produced from the pc to feed the tx on the first transmission or after a band change. Your QDX may not be the problem.
I have also seen a similar effect using the wsjt-x TUNE feature.
I run win 7 home on an old compaq.
73 Ken g4apb?
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Hi Earl,
I have noticed an issue with wsjt-x that no tx audio tones are produced from the pc to feed the tx on the first transmission or after a band change. Your QDX may not be the problem.
I have also seen a similar effect using the wsjt-x TUNE feature.
I run win 7 home on an old compaq.
73 Ken g4apb?
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Mike Perry, WA4MP
Fred Spinner
K9NUD-Steve