Yes that was all checked and okay...
--
wes377@...
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Re: Question About Number of Turns
#qcx
Just a clarification: You mention half turns and are unsure how to count them. Every wire going through the hole of the toroid is always a full turn, whether the soldering point is inside or outside the center. If the soldering point is inside the toroid, the conductor of the PCB will complete the turn to the outside (or vice versa).
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Hi Ed
Thanks for the feedback, I have updated the BPF kit manual.
I recently purchased the QRP Labs BPF kit to support my experiments in RF using my NanoVNA and TinySA Ultra. I have completed 8 of the 10 kits and I am pleased with the results.
When I came stumbling into my home office/lab/ham shack this morning at 4:30 a.m., I happened to glance at a printout of the kit building instructions and somehow noticed a minor typo. In the first line of the Introduction, (LPF) should be (BPF). I am sure Hans has other things to do during his time back in the UK, but I thought I should point this very minor flaw in the documentation out:
Ed, K0KC (now feeling more alert after a strong cup of coffee!)
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Hello Bojan
Not a bad idea at all OM, when the next PCB revision comes along...?
Hi Hans,
Since the QDX-M is out now and it has some place on the board left to use, I wonder if it is possible to make some extra pads? The RX input could be further improved by making a better BPF. I have a 3-pole instead of a 1-pole?BPF in mind.
Please see an example in the attached pdf.
73 Bojan S53DZ
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Hi Hans,
Since the QDX-M is out now and it has some place on the board left to use, I wonder if it is possible to make some extra pads? The RX input could be further improved by making a better BPF. I have a 3-pole instead of a 1-pole?BPF in mind.
Please see an example in the attached pdf.
73 Bojan S53DZ
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On 07/02/2023 22:31, Wes Smith wrote: Hi ... It seems I have the dreaded top row squares on my u3s display. Wes, And you checked here ? Bad joints or faults can show up any time. 73 Alan G4ZFQ
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LM2596 module? Re: Top row squares
Hi Wes,
What do you suspect is the problem with the LM2596 modules?
I just bought a couple of HiLetgo LM2596 Buck Step-down modules to use with my QDX but I haven't hooked them up yet with my new ProAudio Engineering PAE Kx33 14.4 VDC Low RFI power supply.
Ciao!
73, ?Peter W1DAD
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Re: Suggestions for dealing with 50W PA heatsink edges?
Black radiates heat better than white or shiny metal. Think black body radiation physics. It also looks better with rest of the object being black :-)
Enjoy Life, Greg
Live Well, Laugh Often, Love Much
toggle quoted message
Show quoted text
On 2/7/2023 09:08, Roy Appleton wrote: Now you've got me curious. What is the importance of touching up the anodized aluminum with black marker or paint?
Roy
WA0YMH
On Tue, Feb 7, 2023, 6:44 AM Bryan Curl <bc3910@... <mailto:bc3910@...>> wrote:
As a machinist, we use a debur knife, a fine file, or abrasive
buffing wheel to knock sharp edges off, but doing so now will damage
the black anodize finish and expose bare aluminum. If it does not
present a danger of cutting you I would leave it alone. Or Like my
dad always said, if it hurts, stop touching it.?Otherwise take the
sharp edge off with a fine file and touch it up with a marker or
paint pen.
--
regards,
Bryan, N0LUF
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Hi ... It seems I have the dreaded top row squares on my u3s display. ? Worked great for a few years then suddenly this happened today when I turned it on. ? I'm thinking it's probably the Lm2596 module I bought for it . ? Beware of these little modules
Wes
--
wes377@...
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Jim,
The toroids can have the windings pushed together to increase up to a point the power. I did that on mine and it was a big help. Hans has that described somewhere, but I don't remember where. These are the toroids at right angles to the side of the board. The other ones can be spread to be more even if they are not already. Of course only ones for the band you want to change.
From Han's troubleshooting guide:
3) Slightly low power output on one or more bands Low power output is a common complaint and it could just be a matter of tweaking the QDX for best performance. You need to understand which toroid belongs to which band. For the common 80 / 60 / 40 / 30 / 20m model of QDX, L2 + L6 are for 80m, L3 + L8 are for 60/40m, and L4 + L10 are for 20/30m.? Generally if you squeeze together the turns on the appropriate one of L2, L3, L4 (for the band in question) then you will increase the power output. You should NOT go above 5W. It is tempting to go for "maximum smoke" but... if you do so, then will significantly increase the risk of literally seeing maximum smoke. But to go from 3.5W to 4.5W by squeezing the turns is fine. L6, L8 and L10 turns should generally be spaced evenly around almost the entire core circumference.?
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Show quoted text
On Feb 7, 2023, at 14:44, Jim Bennett / K7TXA via < w6jhb@...> wrote:
Well, with a compromise antenna (HOA / CC&R crap to deal with), the extra db helps in marginal conditions. I guess what I'm wondering is just what's the difference in this situation? What components are at risk with the extra 2 volts of input voltage? Obviously the BS170s are able to deal with five watts of power, and I'm staying under that, plus I've added a large heat sink on them. Perhaps Ron or Hans can chime in on this.
Also - are there any tweaks that can be made to get the power up to the specified five watts with nine volts, similar to what is done with L1, L2, and L3 on the QCX+ rigs?
--
Jim / K7TXA
Eagle, ID
SKCC 10447
BUG 301
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Re: Earthquakes in Turkey
Does anyone in the US know how to use the IBAN information to send money via Zelle?
Roy? WA0YMH
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|
Sender notified by
| 02/07/23, 03:27:54 PM |
|
 Hi all
Attached is an image of what has been circulating in Turkey. All these are recommended and trusted relief agencies here. Your donation would not be mis-used. Since we live here we are also able to donate warm children's clothing and bedding to government collection sites in each town - a big problem is the very cold temperatures in the affected area at this time of year.?
All three links are in English:
(bank transfer account listings)?
(Donate by credit card, in TL)
(Donate by credit card in TL, EUR, US$ or GBP)
73 Hans G0UPL
Depending on your browser, this google translate link might work.?
?
--
Colin - K6JTH?
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Re: Earthquakes in Turkey
Hi all
Attached is an image of what has been circulating in Turkey. All these are recommended and trusted relief agencies here. Your donation would not be mis-used. Since we live here we are also able to donate warm children's clothing and bedding to government collection sites in each town - a big problem is the very cold temperatures in the affected area at this time of year.?
All three links are in English:
(bank transfer account listings)?
(Donate by credit card, in TL)
(Donate by credit card in TL, EUR, US$ or GBP)
73 Hans G0UPL
Depending on your browser, this google translate link might work.?
?
--
Colin - K6JTH?
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Hi,
The only difference between the +9V and the +12V version of QDX is the T1 transformer ratio. Which is a TX transformer.
So, all other components should take supply up to +12V. However, as it was said, it is wise not to go too high with the output power. I would go up to 4.5W. This TX configuration does not tolerate higher VSWR at full power as say 2:1.
73 Bojan S53DZ
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Well, with a compromise antenna (HOA / CC&R crap to deal with), the extra db helps in marginal conditions. I guess what I'm wondering is just what's the difference in this situation? What components are at risk with the extra 2 volts of input voltage? Obviously the BS170s are able to deal with five watts of power, and I'm staying under that, plus I've added a large heat sink on them. Perhaps Ron or Hans can chime in on this.
Also - are there any tweaks that can be made to get the power up to the specified five watts with nine volts, similar to what is done with L1, L2, and L3 on the QCX+ rigs?
--
Jim / K7TXA
Eagle, ID
SKCC 10447
BUG 301
|
Me neither. If it bothers you that much, pick up an amp.
|
Jim,
3W is only 2dB less than 5W. You're not going to miss a lot of QSO's because of those 2dB. I wouldn't put my BS170s at risk for that.
Frank PA3CNO?
My newly-built QDX has been working OK, but I recently put my o-scope on the output just to see what power I actually was getting out. Not quite what I was expecting. I wound this radio for use at 9 volts, and measured the "key down" voltage at exactly 9.0 volts. My scope shows only 34.4v / 2.95 watts on 20 meters, and 35.2v / 3.09 watts on 30 meters. Forty meters gives me 37.6v / 3.53 watts and on 80 meters its 44.4v / 4.92 watts.?The power out on 80 is fine, but I was hoping for a bit more on 30 and 20 meters.?
If I adjust my supply voltage on 20 and 30 meters to get me closer to five watts output, is this going to be an issue for those BS170s? I just ran a test on 20 meters, with the power supply sitting at 11.0 volts, I get 42.2 volts on the scope into a dummy load, or about 4.45 watts.
--
Jim / K7TXA
Eagle, ID
SKCC 10447
BUG 301
|
My newly-built QDX has been working OK, but I recently put my o-scope on the output just to see what power I actually was getting out. Not quite what I was expecting. I wound this radio for use at 9 volts, and measured the "key down" voltage at exactly 9.0 volts. My scope shows only 34.4v / 2.95 watts on 20 meters, and 35.2v / 3.09 watts on 30 meters. Forty meters gives me 37.6v / 3.53 watts and on 80 meters its 44.4v / 4.92 watts.?The power out on 80 is fine, but I was hoping for a bit more on 30 and 20 meters.?
If I adjust my supply voltage on 20 and 30 meters to get me closer to five watts output, is this going to be an issue for those BS170s? I just ran a test on 20 meters, with the power supply sitting at 11.0 volts, I get 42.2 volts on the scope into a dummy load, or about 4.45 watts.
--
Jim / K7TXA
Eagle, ID
SKCC 10447
BUG 301
|
Great news, although you might want to discipline your minions (or work on the inventory system).
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Re: QDX Backpack (Hiking) Portable?
#qdx
If you're worried about resonance-- which seems like a good idea since there's no SWR meter on the radio-- then make a dipole cut for the frequency of whichever mode you plan to use.
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Hi Mike. Since your Q6 emitter has 12 volts on receive and 12 volts on transmit, but the collector has zero volts on transmit, I suspect Q6 is bad (open). You can remove it and test to be sure. Good luck.. 73 ... Ron
Ron,
? I read your E-mail of 06/ 02/23 which is in reply to Mr Donnelly.? You inspired me to have another try at resurrecting my Classic QCX 30.?? Please may I pick your brains?? The QCX was plugged in to a bad antenna, after which it did not
transmit, though the side tone still worked.? I removed the BS 170 transistors Q1, Q2 and Q3 ad found I was getting 2.54v on the gates when keyed.? I also checked continuity from C29 to the BNC connector which looked ok.? Only one BS170 transistor survived
removal and that checked out as OK.? I have replaced Q1,Q2 and Q3 an it still does not transmit.? Q6 shows Emitter 12.76V,? 12.63 when keyed.? Collector shows 6.55V and 0.05V when keyed.?? Please can you tell me is the next logical thing to replace Q6?? I
apologise for contacting you like this, but it seemed like a to good an opportunity to miss.
???????? Mike?? G0KCH
?
Sent from for Windows
?
From: Ronald Taylor
Sent: 06 February 2023 13:49
To: [email protected]
Subject: Re: [QRPLabs] QCX Mini On Screen Measurement Not Changing #bpf #troubleshooting
?
If it was transmitting for any length of time with no antenna or dummy load attached, then the three output BS-170 MOSFETs are most likely blown. It is also possible that Q6 and IC3 are bad as well. Start by carefully removing one of the
BS-170s and testing it. Be careful to not damage the board while doing this. If you don't have some kind of solder removal tool, try solder wick and liquid flux for this operation. If one BS-170 is bad, then all three are likely bad. While you have all three
out of the circuit, look for the drive signal at the gates of the MOSFETs. It comes from IC3 and should measure about 2.5 volts DC on your DVM. If that isn't there, then IC3 is bad. If it is there then look for 12 volts on the collector of Q6 while transmitting.
If that isn't there or is there whether keying or not, then Q6 needs to be replaced. Note that the 12 volts should come up rapidly when keyed and diminish slowly when unkeyed, in the absence of a load. If all that is now well, install new MOSFETs and test
the transmitter into the dummy load.?
?
Yesterday I managed to find that I had a short that caused it to always be trying to transmit. I have fixed that and I have successfully completed the alignment procedure.
As far as I can tell the radio is now fully functional with the exception that measuring the output using a QRPLabs dummy load, the output voltage is 3mV during receive and drops to 1mV when transmitting. I assume I have blown something in my PA due to continuously
being transmitting (although throughout my testing thus far, I have been measuring the current draw and it hasn't gone above 200mA).
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Ronald Taylor