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
---
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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
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[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
|
Re: Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz
Is that with a 17M low pass at the output or something else?
If the stock 17M filter is in place then its working so your loosing a lot?
power to it likely 10-20db.
FYI the output low pass filter has to meet conditions for a?
class E.? Also you need about? 8X or more drive compared to 40M
and likely the 74HC is not doing it.
Allison
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Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz
Stock QCX-17 musters only 20 milliwatts output on 28001.7 kHz. Now, admittedly, that's not a whole bunch of output power...and it is only about 38 dB higher than the nearest 'noise', according to the cheap Meili Instruments SM-5010 spectrum analyzer, and that's not too surprising either, given the stock lpf of the QCX-17, followed by an Industrial Communications Engineers Ltd model 411 bpf.
What to do next...
72 / 73,
Bill, N4QA
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Re: U3S - xmit frequency is 200 Hz higher than indicated on display
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
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Re: On 24891.7 kHz, the FT-450D is receiving a sweet note from the transmitter of the stock QCX-17
Hi Dave
Yes, it is and, yes, they are.
Hmmm, you know, there's less than a 2x freq factor, going from 10m to 6m...wondering whether the new QSX could manage that...
72 / 73,
Bill, N4QA
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Re: On 24891.7 kHz, the FT-450D is receiving a sweet note from the transmitter of the stock QCX-17
Bill,
Is this the one you've been "abusing"??? Are all your finals still intact?
I'm actually wondering what I should do with the LPF for the QCX-20 that is on order...
regards,
Dave N3AC
On Sun, Apr 14, 2019 at 4:53 PM n4qa < n4qa@...> wrote: In his QCX manual, sections 7.6 & 7.7, Hans includes some very interesting info about transmitter & receiver sections' filtering, mostly featuring the xmtr lpf and the rcvr bpf circuits.
Currently, using the stock QCX-17, the WM-2 reports something on the order of 300 williwatts into the Bird 10A-MFB-30 attenuator/dummy load.
So, now, I'm wondering aloud:
"Do I wait for the QSX to arrive or do I dive into QCX's lpf and T1 etc whilst waiting?"
72 / 73,
Bill, N4QA
|
On 24891.7 kHz, the FT-450D is receiving a sweet note from the transmitter of the stock QCX-17
In his QCX manual, sections 7.6 & 7.7, Hans includes some very interesting info about transmitter & receiver sections' filtering, mostly featuring the xmtr lpf and the rcvr bpf circuits.
Currently, using the stock QCX-17, the WM-2 reports something on the order of 300 williwatts into the Bird 10A-MFB-30 attenuator/dummy load.
So, now, I'm wondering aloud:
"Do I wait for the QSX to arrive or do I dive into QCX's lpf and T1 etc whilst waiting?"
72 / 73,
Bill, N4QA
|
Re: QLG1 GPS Receiver for use with the Icom IC-7100 or ID-880H
#icom
#qlg1
#gps
did you connect the 3rd pin or 4th pin of the 6 pin header to the Tip of the 2.5mm? Kevin, I've no idea what you are doing, what is this IC9700? But COM ports connect RXD to TXD and TXD to RXD. Crossover. 73 Alan G4ZFQ
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Re: QLG1 GPS Receiver for use with the Icom IC-7100 or ID-880H
#icom
#qlg1
#gps
This post may help me with my problem. I have a IC-9700 and tried to hook up the QLG1 to it, and just like the original poster's description, the Icom did not see it. I will check out one of the MAX3232 and see if that fixes my probelm.
Just one question:
When the advanced radio manual? says to connect the 2.5mm cable like this:
Tip = TxD
Ring = RxD
Sleeve = GND
Is the TxD as referenced by the QLG1 ? in other words, did you connect the 3rd pin or 4th pin of the 6 pin header to the Tip of the 2.5mm?
thanks,
Kevin?
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Has anyone ever connected QLG1 to an Arduino Uno?
Looking for a sketch to verify the output of the QLG1 is working correctly.
thanks,
Kevin
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The Teensy range of microcontroller boards is popular because it has an audio library that makes use of its core's DSP instructions. The developer has created a graphical tool to make this easy.
Rich Heslip VE3MKC and Charlie Morris ZL2CTM have both done some work with this and documented their efforts but there are other things that can be done including experimenting with various filters.
Dave L.
toggle quoted message
Show quoted text
On Sat, Apr 13, 2019 at 12:00 PM, ajparent1/KB1GMX wrote:
For digital methods I just got to the available libraries of code that already do it.
In the linux world that is often the norm for people that roll their own.
For RPi and the various STM32F series there is plenty of code but not a whole
lot of hand holding.? Though for the Pi its easier as it runs Linux and you can
actually develop in place.? Though for some applications a low weight OS or
RTOS might be desirable.
Allison
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Christen Fihl
z_ kevino