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Re: Ultimate 3S #u3s

Rob Giuliano
 

Interesting.  Thanks for the idea!
I am hoping to put out about 250 mW on 10m, and whatever I get on the lower frequencies will be fine.
Halden brought up the bias changes on hs MOSFET (BSN20-7) and I think I experienced this on the BS170.
  I just want one bias setting.
My experience:
  Set bias for 40m and only transmit on 40m -> no issues
  Same bias for 20m and transmit on 20 and 40m -> no issues
  Add 15m and 10m (4-bands) and the BS170 over heats.
  Set bias for 10m -> no issues
  Same bias (10m) and let run on 4 bands - BS170 over heats.
I did not measure this bias level to see if/how much it changed - maybe next time.

Curious if you have noticed a bias voltage changes on those HF bands.  Or if the higher PA voltage makes it easier on the MOSFET?
Just using WSPR for now.  I may investigate other modes later.

Thanks again!
Rob KB8RCO


Re: Ultimate 3S #u3s

Rob Giuliano
 

Thanks Halden - Appreciate the infomration!
I will look into the BSN20-7MOSFET.  I am hoping to put out about 250 mW on 10m, and whatever I get on the lower frequencies will be fine.
I'd be interested in seeing your "PCB adaptor".  Does it allow for the case as part of the heat sink?
Also curious if the bias voltage changes on the lower (HF) bands.  It seems to do that (somewhat) on the BS170.

Thanks again!
Rob KB8RCO


Re: Qgl1 gps question

Roger Hill
 

Hi Art.
That does not sound good. But you might want to inspect the area around pin 2 of IC2 to pin 23 of the RF module for solder blobs, whiskers etc. Maybe even under the RF module.


If nothing found, I agree that a new RF module sounds like it is necessary.

Roger
8P6RX

On 6 Feb 2021, at 11:09, Roger Hill <rhill@...> wrote:

Hi Art.


So it sounds as though you have a faulty IC2 (unlikely), or a short to ground on the output side (pin 2).


You can check the short by removing power from the unit, and with your meter on 'Ohms', check from pin2 to ground...it should be a very high value. A low value will cause the symptoms you are seeing.


Possibly C4 is in backwards.

Roger

8P6RX

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Roger Hill
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On 2021-02-06 10:51, Art Olson wrote:

Eike

Think I have located the problem - no 3.3v on the pin 2 of IC2. When powered up IC2 run hot to the touch.  There is 5.1 v on pin 3 (vin). Verified R7 and R6 are correct values. I have looked for a pinout diagram for the Rf module but could not locate one so don't know the pin numbering on the module. But would seem without any 3.3v from IC2 it wont work. there is 3.3v when powered off on, I assume pin 22 of the RF module

Art
N2AJO


Re: Qgl1 gps question

Art Olson
 

Roger

Yes pin 2 is shorted to ground. Removed IC2 and checked pin 2 - still shorted. Removed C4, C5, C2 and R7 - still shorted to ground. Only connection left is to pin 23 of Rf module which seems it is shorted to ground also. Maybe time for a now gps module


Re: Pin Confusion #u3s

KI7MWA
 

N3MNT:

Okay, but on page 3 of the synth assembly manual, the PCB tracks diagram shows that pins 8, 9, and 10 are connected together...and my DVM agrees.  Pin 8 is not independent.


Re: Pin Confusion #u3s

KI7MWA
 

Another question:  The diagram on page 15 shows +5V supply voltage applied to the PA pin, with the (upper) jumper connecting the PA pin to the +5V pin.  But, with the (upper) jumper installed, the +5V supply could just as well be connected to the +5V pin on the board, because with the (upper) jumper installed the +5V pin is in common with the PA pin. 

You could argue that the +5V supply HAS to be connected to the PA pin if one wants to install the (lower) jumper between the +5V pin and the Heat pin when you want to supply voltage to the oven of the TXCO (should you be using it). 

But if the synth board itself makes a connection between the +5V pin and the Heat pin (my DVM shows 0 ohms resistance between the +5V pin and the Heat pin when the synth board is in place), why would you need the (lower) jumper?


Mini 40 Display Issue Restart

hamhog1
 

I decided to restart from the beginning in troubleshooting my Mini 40.  All I have is the top row of blocks.
Using the Troubleshooting guide, I did the following:
1.  Adjusted R36.
2.  Made sure IC2 was inserted correctly.
3.  Check to be sure no bent pins.  All were seated correctly.
4.  I heard the 20 mhz crystal at 20.005 mhz on shack receiver.  Also saw on scope.
Next I swapped the display board, IC2, and controllers with my Mini 20 which works well.  What I observed:
1.  Both mini 20 and mini 40 IC2s work in mini 20 but no backlight.  Neither IC2s seem to work in mini 40 but with backlight and top row. of blocks.
2.  Both display boards work in mini 20 but no backlight.  Both display boards show top row of blocks in mini 40 with backlight.
3.  Both controller boards work in mini 20 but no backlight.  Both controller boards show top row of blocks in mini 40 with backlight.
Conclusion:  IC2 in mini 40 appears to be okay.  Display board in mini 40 appears to work okay.  Controller board in mini 40 appears to be okay.
Next I measured voltages with my digital multimeter using the voltage sheet from the manual as a guide.
1.  All readings were nominal down to the reading for left side of C45.  Showed 1.28 v instead of 2.42 v. Also C46 showed .85 v instead of 2.30 v.
2.  I did not check ICs 5-10 at this time.
3.  LCD pin 6 showed .48 v instead of 0 v.
4.  LCD pins 7-11 all showed 4.94 v which is quite high.
5.  LCD pin 14 showed 4.94 v instead of 0 v.
6.  LCD pin 15 showed 3.71 v instead of 4.41 v.
Finally I checked continuity and resistance between LCD and IC2 with IC2 removed.  It showed 0.0 ohms resistance.

Trying not to get frustrated.  It probably is something simple, but where to look?

Thanks for any help.
Gary K4VIG


Re: Qgl1 gps question

Roger Hill
 

Hi Art.


So it sounds as though you have a faulty IC2 (unlikely), or a short to ground on the output side (pin 2).


You can check the short by removing power from the unit, and with your meter on 'Ohms', check from pin2 to ground...it should be a very high value. A low value will cause the symptoms you are seeing.


Possibly C4 is in backwards.

Roger

8P6RX

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***************************
Roger Hill
***************************


On 2021-02-06 10:51, Art Olson wrote:

Eike

Think I have located the problem - no 3.3v on the pin 2 of IC2. When powered up IC2 run hot to the touch.  There is 5.1 v on pin 3 (vin). Verified R7 and R6 are correct values. I have looked for a pinout diagram for the Rf module but could not locate one so don't know the pin numbering on the module. But would seem without any 3.3v from IC2 it wont work. there is 3.3v when powered off on, I assume pin 22 of the RF module

Art
N2AJO


Re: Pin Confusion #u3s

N3MNT
 


From Schem.


Re: Qgl1 gps question

Art Olson
 

Eike

Think I have located the problem - no 3.3v on the pin 2 of IC2. When powered up IC2 run hot to the touch.  There is 5.1 v on pin 3 (vin). Verified R7 and R6 are correct values. I have looked for a pinout diagram for the Rf module but could not locate one so don't know the pin numbering on the module. But would seem without any 3.3v from IC2 it wont work. there is 3.3v when powered off on, I assume pin 22 of the RF module

Art
N2AJO


Re: Pin Confusion #u3s

KI7MWA
 

N3MNT: "The lower jumper connects 5V to the heater if using the TCXO."

So, in the case where one is NOT using the TXCO, the synth board makes a connection between the +5V pin and the Heat pin...just for the hell of it?


Re: Black display characters

Daniel Walter
 

Green backlight? My mini has yellow background with black letters. Is the backlight LED actually coloured or is it white?
--
73, Dan  NM3A


Re: Use of the VFO/Signal Generator as a CW TX VFO #vfo

nz0tham@...
 

FWIW AA8V used the N3ZI DDS VFO to build a VFO for older rigs.  The N3ZI DDS VFO had an RIT option and he designed a circuit that used that to move the TX frequency far enough so that it couldn't be heard during RS:
https://www.frostburg.edu/personal/latta/ee/vfo/vfo.html#ritkeying

I have no idea if this would work with the QRP Labs VFO or not but thought I would throw it out there.

73, Bill NZ0T


Re: #u3s #troubleshooting No Spots / not sure transmitting #u3s #troubleshooting #help #lpf

Alan G4ZFQ
 

frequently notice some WSPR ops outside the normal 200 Hz range.
Al,

And some up to a minute out of sync.

WSPRnet.org (or WSJTx for example) on reporting 'out of band' spots? Is it something like +/- 10 Hz?
I've seen some about 6Hz "out of band".
DT is still reported by WSJT, I've seen about 4-5 seconds but decoding may well be compromised well before that.


73 Alan G4ZFQ


Re: Use of the VFO/Signal Generator as a CW TX VFO #vfo

nz0tham@...
 

Great news as I have a VFO/Sig Gen I would like to use with my Heathkit HW-16.  I have a HG-10B VFO that works great with the HW-16 but it would be nice to have a  more accurate frequency readout.  In addition I have an SB-104A and Kenwood TS-530S that I mat try to use the QRP Labs VFO with.

Thanks Hans!

73, Bill NZ0T


Re: Pin Confusion #u3s

N3MNT
 

For the PA 5V, heat pins there are two of each connected together.  The lower jumper connects 5V to the heater if using the TCXO.  The upper jumper connects 5V to PWR for the final power.  If you power the finals via 12V you do not use the upper jumper. 


Re: Black display characters

N3MNT
 

The mini is supplied with a green backlight and black letters because it allows the backlight to be turned off ( to reduce pwr consumption)  and still be able to read screen.  With the blue backlight the letters are white and very difficult to read without the backlight on.


Pin Confusion #u3s

KI7MWA
 

Page 15 of the U3S construction manual says: "To run the transmitter using the 5V supply, be sure to connect a wire between the +5V and PA pins. This is shown by the short red horizontal line in the diagram (below)."  But, in the diagram there are actually TWO short red horizontal lines, one between the second and third pins of the 4-pin header next to the capacitor labeled C1, and another between the second and third pins of the 11-pin header at the edge of the board, the pins labeled +5 and Heat.

With no jumpers installed, my DVM shows continuity between the +5 and Heat pins.  Is this correct? Or do I have a short somewhere?

With the Si5351 module removed I have NO continuity between the +5 and Heat pins.  Does this mean I have a short somewhere on the Si5351 module board?


Re: Black display characters

Ted 2E0THH
 

Am I misreading this?
The Mini is supplied with a green screen because of its lower power consumption.
The QCX and QCX+ are supplied with a blue screens.
If you haven't the backlight turned on, you may never know  

73s Ted


Re: N1MM+ CAT control with QCX+

KEN G4APB
 

Hi Hans, I did not want to give you extra work, I just wanted to know the correct syntax for stringing commands together. I appreciate I may be pushing the limitations of the qcx, but sometimes a simple idea (on my part) proves no so.
The ‘simple idea’ was to run the qcx-mini using TS-480 CAT commands controlled from wsjt-x (now v2.3.0) switching the qcx between wspr beacon mode and normal rx mode (VFO A) and back, controlled by a bandhopping feature in wsjt-x that calls a batch file to run a command line. 

Then weird effect is that if I try to enable beacon mode AND preset the VFO A to a particular frequency all in one command line as I showed, I seem to get an odd combination of both. On wspr beacon ‘waiting’ screen, instead of  displaying the preset beacon frequency, it shows vfo A and its (rx) frequency, and when it actually starts to transmit , it is not on the beacon preset frequency, and the display starts the call sign with an underscore as if in editing mode, and I get no ‘spots’ as a result.
Without CAT control, beacon mode works fine, but as i said previously, during the beacon ‘waiting’ time, ( say if I set FRAME to 10 minutes), the qcx is not in receive mode, hence my attempts to switch it to rx during this wait time.
73 Ken G4apb 

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