Re: QCX Frequency Calibration
Erik
the WSPR passband is narrow enough that it is easy to be out of it, and the PLL in the rig takes some time to calibrate even with the GPS attached.? Good idea to find your frequency in a CW transmission on RBN.? when you think you are close, try setting up frequencies at each end of the WSPR frequency span and possibly middle to see if you get any reports.?
73 Curt
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I just Googled "30pF trimmer capacitor" and got over 10 million hits! Amazon seems to sell them, too.
Jack, W8TEE
On Tuesday, September 11, 2018, 11:05:35 AM EDT, Gadget Lust <gadgetlust@...> wrote:
So, I need a C1 30pf trimmer, which I am missing from a current build due to cannibalizing for something else.? I thought these would be easy to find, but the CYMI types appear to be relatively non-existent on Digikey and Jameco, and Hans has stopped selling them.? Does anyone? have a source so I can complete this build?
Thank you and 73,
--
Harv
K2PI
Warrenton, VA
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So, I need a C1 30pf trimmer, which I am missing from a current build due to cannibalizing for something else.? I thought these would be easy to find, but the CYMI types appear to be relatively non-existent on Digikey and Jameco, and Hans has stopped selling them.? Does anyone? have a source so I can complete this build?
Thank you and 73,
--
Harv
K2PI
Warrenton, VA
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Re: QCX Frequency Calibration
What about a CQ Call on the reverse beacon net.? They indicate your frequency.
Martin
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OK Chris.? Sounds good.
I can confirm that the X2 option on WSJT works very nicely with class D amplifiers
I have tried it running in 'split' mode and it appears that it's just the bandwidth of the
modulation that is doubled rather than the audio frequency.
So, hopefully? on RX, just straight in on 2200m
then on TX in split mode. With a dial frequency of 273.5 in USB, your transmitter would add 1500Hz to generate 275kHz
which is then divided by 2 in the amplifier to give 137.50kHz.
However, netting onto another station is 'interesting'. -? But, with your QRO signal, I would just call CQ? !!
Hope this means I can work you on JT9? etc this season :)
CUL
David? G0MRF
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Re: U3S OCXO Ultimate relay 5W HF PA corrupted display
Hi Stuart / Ken,
A couple of considerations.
If the PA is built with cosine shaping under the control of the U3,
AN004 rather than the standalone variant.
The U3 MCU may not like driving it's data lines into the now
unpowered decoder IC on the PA PCB,
hence display corruption as two of these data lines are shared with
the LCD.
In addition to switching the supply voltage to the PA,
the RF connections to the "now dead" PA PCB will need to be bypassed
Alan
On 11/09/2018 08:35, Stuart Cameron
Vk5ade wrote:
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Hi Ken, thank you for your reply, the mod i have done was to break
the 12 volt supply to the Amp via the spare switch completely
separate to the 5 volt supply.
It should have been a simple mod and i thought it should have not
affected the main 5 volt to the U3S.
Very strange i hope this make sense.
Regards
Stuart Vk5ade
??
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Re: U3S OCXO Ultimate relay 5W HF PA corrupted display
My guess it might have something to do with the data lines that are shared with the display. Perhaps when the voltage to the PA is cut off those lines go low and their state can't be changed by data sent to the display from the U3S.?
--Al
WD4AH
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Re: U3S OCXO Ultimate relay 5W HF PA corrupted display
I have same kit built with relay board. Very happy with results.?
It will show corrupted screen like yours if I turn PA Amp off. I just don¡¯t try to turn it off anymore.?
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On Sep 11, 2018, at 00:35, Stuart Cameron Vk5ade < stuart@...> wrote: Hi Ken, thank you for your reply, the mod i have done was to break the 12 volt supply to the Amp via the spare switch completely separate to the 5 volt supply.
It should have been a simple mod and i thought it should have not affected the main 5 volt to the U3S.
Very strange i hope this make sense.
Regards
Stuart Vk5ade
??
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Hi Andy,
I did see OZ8PZ¡¯s R5 modification on the QRP Labs website. ?I'm just curious why you decided to go with a 33K resistor instead of something closer to the parallel values of the original 56K resistor and OZ8PZ's 18K resistor which equals about 13.6K when combined?
The original OCXO voltage divider circuit supplies a maximum of about 4.25v to the BS170 MOSFET gates to control the current flow through those BS170¡¯s. ?OZ8PZ's modification reduces this maximum to about 2.9v. ?His findings seem to correlate nicely with the predicted current shown in the ¡°On-Region Characteristics¡± chart on the BS170 data sheet.
Using a 33K resistor for R5 in the voltage divider should result in about 3.8v maximum applied to the BS170 gates. ?At that gate voltage the data sheet predicts the current could still be excessive, so I'm interested in what you find yours does.
73,
John
AA7US
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Re: CLOCK Kit problem - incorrect LOC calculation
#clock
#qlg
Just for possible checking (by Hans ? )- screenshot of reported coordinates (in sync with QLG1 output) and correct calculated LOC (JN79EX)
On CLOCK Kit display reported like JN79EW.
Now is information complete I suppose...
-dst-
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Hello Vernon,
Will reply by direct mail, seen your e-mail now, I had missed it,
sorry
Monday, September 10, 2018
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Chris let me know if and when you TX on 136khz again...will listen Vernon - VE1VDM -- 2E0ILY Best regards, Chris mailto:chris@...
--
Best regards, Chris Wilson (2E0ILY)
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Hello David,
Thanks for the reply. I was trying to get my head around this but have
worked it out via experimentation :) I wanted to use my TS-590 via the
low power output from it's DRIVE socket. Recently the WSJT-X people
have added a check box for the tones to be X2 or X4. That meant I
could theoretically use the 590 to drive my Class D amp direct on LF
by outputting around twice the required frequency. Previously before
the X2 and X4 options I had to output at 136kHz and use a frequency
doubler. What I have founds is that desiring a frequency of 137.550kHz
I need to set the TS-590 dial frequency to 273.550kHz and the tone in
WSPR to 1550 Hz. I was initially believing I would only have to
multiply the dial frequency of 136kHz by two. I Told you I was hopeless
with the maths! Thanks again!
Tuesday, September 11, 2018
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Hi Chris.
The simple answer is 137.55kHz.
Since the output of the transmitter is 275.10 and it is divided by 2
However, I think your question may be a little more complex then
initially read. Do you mean dial frequency in USB mode rather than 'transmitting on'?
73
David -- 2E0ILY Best regards, Chris mailto:chris@...
--
Best regards, Chris Wilson (2E0ILY)
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Hi John,
I'm not going to be able to measure current draw for a couple of days but in the qrp labs shop page re the ocxo Stig, OZ8PZ, said that as stock his ocxo drew 0.5A at start up, after putting a 18k resistor in parallel,? his now draws 200mA from cold and 100mA warm.?
A 1/4w resistor will just fit as a replacement.
Andy
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Hi Chris.
The simple answer is 137.55kHz.
Since the output of the transmitter is 275.10 and it is divided by 2
However, I think your question may be a little more complex then initially read.? Do you mean dial frequency in USB mode rather than 'transmitting on'?
73
David
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Re: U3S OCXO Ultimate relay 5W HF PA corrupted display
Hi Ken, thank you for your reply, the mod i have done was to break the 12 volt supply to the Amp via the spare switch completely separate to the 5 volt supply.
It should have been a simple mod and i thought it should have not affected the main 5 volt to the U3S.
Very strange i hope this make sense.
Regards
Stuart Vk5ade
??
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Re: QCX Frequency Calibration
I would have thought the frequency counter would use the 20MHz crystal, so it would not be affected by changes to the 8.5 setting. Rich Yes, I see from the manual that it does. But it is still not possible to calibrate without an accurate outside reference, or counter. (If Eric was using the correct connections and settings then it seems he should see some change using menu 9.5/6. I am suspicious that he was not measuring the generator output. It does not matter, these changes would have no significance regarding calibration.) 73 Alan G4ZFQ
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Re: CLOCK Kit problem - incorrect LOC calculation
#clock
#qlg
Hi,
so nobody here with the same or similar experience with Clock unit LOC calculation/display accuracy?
-dst-
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Re: U3S OCXO Ultimate relay 5W HF PA corrupted display
Hi Stuart,
need a bit more info from you but here goes;
1) what actually is 'the mod'? If you inserted a break in the 5V to PA pins, then are you sure you switched the correct pin off? (i.e PA pin and not 5V pin).?
2) Are you running the PA from a separate supply other than 5v? Are you sure you dont still have a link between these two pins?
73 Ken G4APB
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Re: Solder temp for QCX Board
Interesting views.
My iron is at 280C
I put the iron against the parts for 0.5-1 second and then apply very thin solder to the parts for max 0.5 seconds, not to the iron, and then remove the iron and solder.
Its a kind of rithm you get into.
I learned it when I was soldering PCB's manually for some time as a job
--
Erik@Home
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U3S OCXO Ultimate relay 5W HF PA corrupted display
Hello group, i have completed the kit with the 5w HF PA all working ok.
I have done the mod to be able to switch of the Amp off from the left top front switch.
On power up with amp on all is ok but if iswitch of the Amp the screen is corrupted message.
The U3S should be able to run of the 5 volt supply as usual.
I am not sure why this acting this way.
Regards
Stuart Vk5ade
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jjpurdum
Alan de G1FXB
AA7US
Lexa, OK1DST
M0RON