Re: A somewhat more complete description of my (ab)use of the QCX-17 and QCX-80 transceivers
Hello Nigel.
Thank you for your kind comments !
Sounds like your QCX-30 will be a very handsome rig !
Looking at the? QCX schematic, I am considering lifting one end each of C27 & C28, and jumpering the C29 end of L3 to the rf connector end of L1.
That would facilitate using an external low-pass filter which could be home-brewed or purchased for the band of interest, .
Additionally, I would be very interested in seeing ideas/designs for a band-switched version of the QCX receiver's band-pass filter & phase-splitter circuits !
Or...wait a minute..how about removing T1 and replacing it with small terminals to which one could temporarily attach a specially terminated? 'T1' of choice !?
72 / 73,
Bill, N4QA
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Hi Andy,
Thanks for the reply. Yes, I set up just like you describe. But I am still afraid that I didn't quite hit the sweet spot because of the drift I am seeing.?
The fact that I am seeing negative values for drift, seems to indicate that my 27 MHz clock is not at the minimum frequency. And since the setup for the OCXO specifically looks for the minimum, I am afraid that I am not at that sweet spot. But before I tear it apart to redo the calibration, I thought I would look for some confirmation of that and other advice as well.
--
Sverre
?
LA3ZA, http://la3za.blogspot.com
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SOLVED> Re: U3S - xmit frequency is 200 Hz higher than indicated on display
DOH! What a dummy.
I forgot to change the calibrate step time on this U3S kit - I did go through this on U3S #1 but completely forgot on #2. Now we are calibrating and the reference frequency is changing. Can't believe I missed this. Thank you Hans for the help.
--
John, WB5THT
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?I received my QCX kit it a couple of weeks which I ordered on 3-16. But the extra QCX programmed ATMEL chip which was ordered on 3-18? hasn't left Turkey
or shown any movement since 3-22
Joe
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Re: A somewhat more complete description of my (ab)use of the QCX-17 and QCX-80 transceivers
Greetings from sunny South Africa Bill :-)?
VERY interesting report back from your QCX adventures! Many thanks for sharing - I for one sincerely appreciate, thank you.
Sooooooo, I have yet to start construction of my QCX - 30 for a number of reasons including collection of all hardware and metal bashing I have planned for the enclosure (which is a di-cast aluminium case). Reading your posts I am now wondering if perhaps could be of value to purposely make change to intended filter (switched maybe? Need to revisit schematic) and include a selectable output filter / atu arrangement (case has space as intended to include internal batteries)? Having a MULTI band QCX is VERY appealing <BIG smile>.
Will appreciate your (and any one else who cares to chime in) feedback / ?comments as I suspect will many others...
Keep the feedback coming, it is making for an interesting read :-)?
73
Nigel ZS6RN ex G8DEV?
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Hi Sverre,?
I have built 4 of the OCXO, how did you set the OCXO up? Mine are all inside a qrp-labs.com case with no issues.?
I used Argo software and a FT 817ND as receiver with a lead from spk out on the 817 to mic in on laptop, set u3s to tx fskcw as stated in manual and watch the signal frequency in Argo drop then stabilise. At some point it will rise, this is too far,back off a touch and you will be fine. My OCXO u3s don't drift although sometimes a spot may say -1.
Good luck?
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.
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Re: Has anyone ever connected QLG1 to an Arduino Uno?
Exactly. You can always define another instance of the Serial object. FWIW, I would leave pins 2 and 3 open on the Uno/Nano, as those are the only external hardware interrupt pins and I usually avoid using them as you never know when you may want to add an external interrupt.
Jack, W8TEE
On Monday, April 15, 2019, 4:08:46 AM EDT, Christen Fihl <Christen@...> wrote:
Sounds easy as you only need to send data into the ?rx pin and send it to console at each newline.?
Maybe do use a SoftwareSerial on another pin if rx port gets blocked by the usb console connection
--
73 Christen Fihl, OZ1AAB
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I had the same problem with my 30m QCX.
--
73
Richard
G4TGJ
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I just assembled an OCXO and have had it running for a few days with the U3S at 18 and 14 MHz. The U3S is in the QRPLabs enclosure. It turns out that I need to have the lid off in order to reduce drift to 0. Otherwise I will get drift in the -1,-2,-3 range. This seems to indicate a heating problem, could it be that it gets too hot with the lid on?
And how should I interpret the drift? Does it mean that the 27 MHz reference is drifting down in frequency during the transmission with about 27/14 times the reported drift? Could it be that I haven't found the proper sweet spot for the setting of the OCXO?
--
Sverre
?
LA3ZA, http://la3za.blogspot.com
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Dear Hans,
??? Could you consider sending packages via a courier like DHL or TNT? It is true that there would be higher costs for buyers, but parcels would be fast and very important without loss. I have asked ?here in Romania at ?TNT, DHL and many others and ?without a continuity contract any package to be picked up from Turkey cost at least 80Euro without VAT. Assuming that they are called locally from Turkey and not through intermediaries as is my case the?costs would probably be below 40- 50Euro excluding VAT.
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Re: Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz
Absolutely, Geoff !
72 / 73,
Bill, N4QA
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Hi Chris,
Several QCX 20m version builders, myself included,? found that the output filter capacitors C25 and C26 (390pF NPO ceramic) were quite lossy.? This may be due to a bad batch of capacitors from the manufacturer.? I found that holding the key down for a few seconds caused the output power to slowly rise and C25 and C26 to warm up - I checked this using an infra-red thermometer.? ?
I cut out C25 and C26 and soldered 330pF + 56pF NPO ceramic to be back of the PCB (I don't have any 390pF NPO in my new components box) and the power went up to about 3W using a 13,8V PSU.? It also remained constant when the key was held down for a few seconds.??
I believe that this problem has only been reported on the 20m version of the QCX..
Richard G3OTK
On Monday, 15 April 2019, 05:11:09 BST, Chris Hobbs <chris@...> wrote:
[I know there is a recent thread on this topic, but I think I'm experiencing something different]
Hi All!
I'm new to the QCX and finished building my -20 a couple of weeks ago. Other than a bad solder joint on the LED backlight everything seemed to be working well and I was able to go through the calibration steps.
Now that I've got an antenna up I'm ready to start actually playing with it, and I've discovered that I'm not getting anywhere close to the power I should be for my input voltage (13.7VDC from an Astron power supply). I'm only seeing 1.0W on my MFJ-971 tuner into a 50-ohm dummy load.
I've gone through the troubleshooting in section 6.5 of the manual. The pin at L1 is showing 0.74W on the internal watt-meter. The drains of all three BS170s however show 5.2W. I know the manual says this is an even less reliable measurement, but that's almost an order of magnitude difference.
The manual suggests that if you have power at the mosfets but not at L1 then the LPF is to blame. It doesn't cover what the issue might be if there is RF at L1 but it's really low.
I've read that removing turns from L1-3 can help, but I have a hunch the problem I've got is something more significant than what that solution might provide.
Any thoughts on what I should be looking at first?
Thanks in advance!
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Re: Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz
Well that proves that the LOW pass filter is doing its job then!!
On 15/04/2019 02:56, n4qa
at_hotmail.com wrote:
toggle quoted message
Show quoted text
Hi Allison.
As per my initial post on this topic, I will answer yes *and* yes
to your first sentence above - Both the stock internal lpf and an
external filter for 28 MHz are deployed.
A single yes to sentences two & three above.
However, as to your sentence four above, I note that the datasheet
for the 74ACT00N indicates that it possesses adequate drive
current capability for Q1,Q2,Q3, with a maximum switching speed in
the single digit ns range.
This is not to say that it was ever expected that the QCX-series
should operate flawlessly in the near-low-vhf range of frequencies
ie 10m band, for example.
I'm only saying that, with a little touch here and there, it is
certainly possible to obtain *some* success there.
Tnx & 72 / 73,
Bill, N4QA
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Re: Has anyone ever connected QLG1 to an Arduino Uno?
Sounds easy as you only need to send data into the ?rx pin and send it to console at each newline.?
Maybe do use a SoftwareSerial on another pin if rx port gets blocked by the usb console connection
--
73 Christen Fihl, OZ1AAB
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Re: Has anyone ever connected QLG1 to an Arduino Uno?
Hello Kevin,
what is exact your problem ? Maybe we have the same problem.
I have here Arduino UNO and Arduino Mega. With UNO I cannot receive the
NMEA strings correct,
with Mega it works fine.
--
73
Uli
DF5SF
Pirmasens, JN39te
---
Diese E-Mail wurde von Avast Antivirus-Software auf Viren gepr¨¹ft.
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Re: QLG1 GPS Receiver for use with the Icom IC-7100 or ID-880H
#icom
#qlg1
#gps
Hi Kevin
You can't connect a QLG1 directly to the IC-9700 as the QLG1 is 5V TTL level and the radio is RS-232. You need to implement an level converter as the MAX232 or even easier pick up an ready made converter on ebay, just search 'RS232 to TTL converter'.
Per
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Re: QLG1 GPS Receiver for use with the Icom IC-7100 or ID-880H
#icom
#qlg1
#gps
Kevin, But COM ports connect RXD to TXD and TXD to RXD. Crossover. And if you connect the IC9700 TXD you must be sure it sends TTL. If not some sort of conversion is required. A resistor/zener is the simplest way. 73 Alan G4ZFQ
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Re: U3S - xmit frequency is 200 Hz higher than indicated on display
Hi John
See
What are you using for the parameter "Cal {Time Step}"?
73 Hans G0UPL? ?
On Mon, Apr 15, 2019, 00:10 John Canfield < bucket@...> wrote: Thank you Krause, your English is better than some with English as a first language ;-) I have set the U3S up to do a calibration every few minutes, the oscillator must be stable because there is usually no change required ( = ).
--
John, WB5THT
|
[I know there is a recent thread on this topic, but I think I'm experiencing something different]
Hi All!
I'm new to the QCX and finished building my -20 a couple of weeks ago. Other than a bad solder joint on the LED backlight everything seemed to be working well and I was able to go through the calibration steps.
Now that I've got an antenna up I'm ready to start actually playing with it, and I've discovered that I'm not getting anywhere close to the power I should be for my input voltage (13.7VDC from an Astron power supply). I'm only seeing 1.0W on my MFJ-971 tuner into a 50-ohm dummy load.
I've gone through the troubleshooting in section 6.5 of the manual. The pin at L1 is showing 0.74W on the internal watt-meter. The drains of all three BS170s however show 5.2W. I know the manual says this is an even less reliable measurement, but that's almost an order of magnitude difference.
The manual suggests that if you have power at the mosfets but not at L1 then the LPF is to blame. It doesn't cover what the issue might be if there is RF at L1 but it's really low.
I've read that removing turns from L1-3 can help, but I have a hunch the problem I've got is something more significant than what that solution might provide.
Any thoughts on what I should be looking at first?
Thanks in advance!
|
Re: Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz
Hi Allison.
As per my initial post on this topic, I will answer yes *and* yes to your first sentence above - Both the stock internal lpf and an external filter for 28 MHz are deployed.
A single yes to sentences two & three above.
However, as to your sentence four above, I note that the datasheet for the 74ACT00N indicates that it possesses adequate drive current capability for Q1,Q2,Q3, with a maximum switching speed in the single digit ns range.
This is not to say that it was ever expected that the QCX-series should operate flawlessly in the near-low-vhf range of frequencies ie 10m band, for example.
I'm only saying that, with a little touch here and there, it is certainly possible to obtain *some* success there.
Tnx & 72 / 73,
Bill, N4QA
|
M0RON
jjpurdum
Christen Fihl