Date   

Paddle Key Compatibility with QCX

Gwen or Jim Koreltz
 

I'm brand new to this forum and this is my first message.  I'm getting back into amateur radio after a very long hiatus.  I had a blast building the 40-m version of the QCX.  I have a Vibrokeyer (single paddle key) on order from Vibroplex.  Can anyone tell me the correct CW mode setting for this kind of key?

Tnx, Jim wa7ktf


Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Hi Alan,
Game over as I don't have a replacement for IC3.
I did order another 40 QCX and i will take all the experience
and now with skills at voltage checking, do better next time.
Again thanks and best 73's
George

On Wed, Dec 11, 2019 at 2:53 PM Alan G4ZFQ <alan4alan@...> wrote:
> CLK 1
>     goes from 1.7 on receive to zero on transmit.

George,

That's enough to tell it is going to TX mode.
You need to remove IC3 and test the voltages on it's pin 4 and pin 12
pads, RX and TX modes.

IC3 can be removed by carefully cutting each leg then removing each leg
separately.

73 Alan G4ZFQ
>
>         IC3 looks as if it has failed. If pins 1,2 are high then pin 1
>         should be
>         low.
>         What are the voltages on Q1,2,3?
>
>         Also it looks as if IC1 is not sending a TX signal to IC3 and
>         that Clk2
>         is not turned on for TX.
>         Is it going into TX mode? Does IC1 pin 3 go low when the "Key"
>         switch is
>         pressed?
>
>         




Re: No output QCX 40 output drains show 1.6 watts in receive

Alan G4ZFQ
 

CLK 1
goes from 1.7 on receive to zero on transmit.
George,

That's enough to tell it is going to TX mode.
You need to remove IC3 and test the voltages on it's pin 4 and pin 12 pads, RX and TX modes.

IC3 can be removed by carefully cutting each leg then removing each leg separately.

73 Alan G4ZFQ
IC3 looks as if it has failed. If pins 1,2 are high then pin 1
should be
low.
What are the voltages on Q1,2,3?
Also it looks as if IC1 is not sending a TX signal to IC3 and
that Clk2
is not turned on for TX.
Is it going into TX mode? Does IC1 pin 3 go low when the "Key"
switch is
pressed?


Two QCX kits (80m and 40) - both with shorts on Si5351A - fixed

Nick Austen
 

Summary: check for shorts between legs of the surface mounted devices before you start (additional cautionary note to add to manual?)

Background: I first bought and built one 40m QCX - all worked first try - then accidentally blew it up with a stray remnant resistor leg shorting 12v to 5v - now fixed after replacing the processor, and other digital chips as well as voltage dropping diodes (first replacement Si5351A replaces twice as first replacement did not oscillate at crystal frequency). All perfect now.

Then bought two more (one to give as a gift). I built them in parallel. Neither worked (initially).

After searching and checking, I looked at the quadrature outputs of the Si5351A’s. One unit had an odd looking three-level signal on the oscilloscope- which I eventually realised was the sum of the two quadrature outputs - they were shorted.
After careful magnified viewing I saw a short right on the pins of this synthesizer (not put there by me).
Solder wick fixed that quickly.

The second unit had only one of the quad outputs oscillating- the other was at 0 vdc. Found another short - this time from the second quad  output to the ground pin. This was also fixed by quick application of solder wick.

All working now - phew.

Conclusion - don’t let it put you off - just check the legs of the Si5351A on the bare board before you start - it may save you some disappointment:

Still highly recommend - the best kit I have seen.

Thanks again,
Nick
(VK6FABE)


Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

D!1 at output is 3.3 and IC1 pin 1 is  1.8 assuming that is top right pin.


On Wed, Dec 11, 2019 at 12:33 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
Alan,
The drain and gate on Q1 Q2 and Q3 are 5 v and the source 0. CLK 1 goes from 1.7 on receive to zero on transmit.
Not sure of pinout on IC1 directly. 
George






On Wed, Dec 11, 2019, 3:54 AM Alan G4ZFQ <alan4alan@...> wrote:
> In transmit nothing on the IC3 changes.

George,

IC3 looks as if it has failed. If pins 1,2 are high then pin 1 should be
low.
What are the voltages on Q1,2,3?

Also it looks as if IC1 is not sending a TX signal to IC3 and that Clk2
is not turned on for TX.
Is it going into TX mode? Does IC1 pin 3 go low when the "Key" switch is
pressed?

73 Alan G4ZFQ


>     IC3 Voltages LCD unplugged:
>     some values rounded off.
>     1) 5
>     2) 5
>     3) 5
>     4) .02
>     5) .01
>     6) 5
>     7) 0
>     8) 5
>     9) 0
>     10) 0
>       11) 0
>     12) 5
>     13) 5
>     14) 5
>





Re: Ultrasound operation of U3S #u3s

eralmu@...
 

Hi Hans,

last week I made some succesful tests with the U3S on 475 kHz and 137 kHz (WSPR2 and WSPR15 in mixed mode!). Now I'm trying to go down to 8.27 kHz and below. Thats why I designed a a 5 pole Chebysheff filter (fg abt 10 kHz) for your LPF switch kit. The filter works fine.
My probelm is: The U3S does not produce an 8 kHz signal. The minimal frequency I could achieve was 28 kHz. Now I assume that there is possibly the same situation as described above.

Is there any chance to change the internal dividers to go down to 8 kHz possibly also to 4 kHz? Or ist the only way to use an additional divider with the need of changing the WSPR firmware to do this?

My goal is to transmit on 8.27 kHz (possibly also down to 4 kHz or between) with WSPR2 and WSPR15 mode.

73

Albrecht


Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Alan,
The drain and gate on Q1 Q2 and Q3 are 5 v and the source 0. CLK 1 goes from 1.7 on receive to zero on transmit.
Not sure of pinout on IC1 directly. 
George






On Wed, Dec 11, 2019, 3:54 AM Alan G4ZFQ <alan4alan@...> wrote:
> In transmit nothing on the IC3 changes.

George,

IC3 looks as if it has failed. If pins 1,2 are high then pin 1 should be
low.
What are the voltages on Q1,2,3?

Also it looks as if IC1 is not sending a TX signal to IC3 and that Clk2
is not turned on for TX.
Is it going into TX mode? Does IC1 pin 3 go low when the "Key" switch is
pressed?

73 Alan G4ZFQ


>     IC3 Voltages LCD unplugged:
>     some values rounded off.
>     1) 5
>     2) 5
>     3) 5
>     4) .02
>     5) .01
>     6) 5
>     7) 0
>     8) 5
>     9) 0
>     10) 0
>       11) 0
>     12) 5
>     13) 5
>     14) 5
>





Re: No output QCX 40 output drains show 1.6 watts in receive

Alan G4ZFQ
 

In transmit nothing on the IC3 changes.
George,

IC3 looks as if it has failed. If pins 1,2 are high then pin 1 should be low.
What are the voltages on Q1,2,3?

Also it looks as if IC1 is not sending a TX signal to IC3 and that Clk2 is not turned on for TX.
Is it going into TX mode? Does IC1 pin 3 go low when the "Key" switch is pressed?

73 Alan G4ZFQ


IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5


Re: No output QCX 40 output drains show 1.6 watts in receive

Charles W. Powell
 

Alright.  I hadn’t been following the thread all that well.

73,

Charles - NK8O

On Dec 10, 2019, at 7:49 PM, George Korper <georgekorper@...> wrote:

Hi Charles,
My problem is no output receive is okay. 
Thanks, 
George. 

On Tue, Dec 10, 2019, 7:34 PM Charles W. Powell via Groups.Io <doctorcwp=yahoo.com@groups.io> wrote:
Start tracing your audio chain. You can use a screwdriver to “inject” hum into the op amp if you are careful not to short pins.   I have had several QCX units I have repaired that had a fault near IC8.  It’s worth checking.  You can figure out where you lose signal this way and separate an audio fault from something upstream.   You said you don’t HEAR the alignment tone, but did you get a meter peak when you adjusted C1?

73,

Charles

On Dec 10, 2019, at 6:58 PM, George Korper <georgekorper@...> wrote:

I understand with the voltage on the gate of the output transistor, it is consistent  with the output on the drain.
but is the IC3 bad? My electronics education is not deep enough to come up with it ( hi hi) Everything was working fine so at least I can rule out
bad soldering, but replacing the output transistors was stupid. I NOW HAVE LEARNED WHY YOU INSIST ON VOLTAGE MEASUREMENT FIRST. Thanks for being a good Elmer. 


On Tue, Dec 10, 2019 at 10:37 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several 
components to blow in the PA, replacing one component may blow it again. 
Voltage readings are important. Also check voltages after you remove a 
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed 
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove 
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ














Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Hi Charles,
My problem is no output receive is okay. 
Thanks, 
George. 

On Tue, Dec 10, 2019, 7:34 PM Charles W. Powell via Groups.Io <doctorcwp=yahoo.com@groups.io> wrote:
Start tracing your audio chain. You can use a screwdriver to “inject” hum into the op amp if you are careful not to short pins.   I have had several QCX units I have repaired that had a fault near IC8.  It’s worth checking.  You can figure out where you lose signal this way and separate an audio fault from something upstream.   You said you don’t HEAR the alignment tone, but did you get a meter peak when you adjusted C1?

73,

Charles

On Dec 10, 2019, at 6:58 PM, George Korper <georgekorper@...> wrote:

I understand with the voltage on the gate of the output transistor, it is consistent  with the output on the drain.
but is the IC3 bad? My electronics education is not deep enough to come up with it ( hi hi) Everything was working fine so at least I can rule out
bad soldering, but replacing the output transistors was stupid. I NOW HAVE LEARNED WHY YOU INSIST ON VOLTAGE MEASUREMENT FIRST. Thanks for being a good Elmer. 


On Tue, Dec 10, 2019 at 10:37 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ











Re: No output QCX 40 output drains show 1.6 watts in receive

Charles W. Powell
 

Start tracing your audio chain. You can use a screwdriver to “inject” hum into the op amp if you are careful not to short pins.   I have had several QCX units I have repaired that had a fault near IC8.  It’s worth checking.  You can figure out where you lose signal this way and separate an audio fault from something upstream.   You said you don’t HEAR the alignment tone, but did you get a meter peak when you adjusted C1?

73,

Charles

On Dec 10, 2019, at 6:58 PM, George Korper <georgekorper@...> wrote:

I understand with the voltage on the gate of the output transistor, it is consistent  with the output on the drain.
but is the IC3 bad? My electronics education is not deep enough to come up with it ( hi hi) Everything was working fine so at least I can rule out
bad soldering, but replacing the output transistors was stupid. I NOW HAVE LEARNED WHY YOU INSIST ON VOLTAGE MEASUREMENT FIRST. Thanks for being a good Elmer. 


On Tue, Dec 10, 2019 at 10:37 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ











Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

I understand with the voltage on the gate of the output transistor, it is consistent  with the output on the drain.
but is the IC3 bad? My electronics education is not deep enough to come up with it ( hi hi) Everything was working fine so at least I can rule out
bad soldering, but replacing the output transistors was stupid. I NOW HAVE LEARNED WHY YOU INSIST ON VOLTAGE MEASUREMENT FIRST. Thanks for being a good Elmer. 


On Tue, Dec 10, 2019 at 10:37 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ




Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ




Re: Setting up & alignment problems.

ajparent1/KB1GMX
 

If you have no audio thats the starting point.

First check to see that you have 5V at the regulator output.  Then does the display light and communicate.

The volume control due to location of other parts is tricky so make sure you
haven't shorted the terminals or not connected them!

turn the volume up some and with headphone plugged it can you hear any
hiss?   Touch a screw driver tip to the middle (wiper lead) of the volume
control hear a click or buzz?

WIth a  simple meter (digital or analog) measure voltages at 
IC 10 pin1 and IC9 pin 1 do they come close to the listed voltages in
the manual?

NOTE use the trouble shooting procedure in the manual.  Simple
problems can be hard to find if this (radio construction or electronics)
is all new to you.

Since you didn't solder in the SI5153 if its not doing its thing look at
what you did solder like the ATMEGA328P MPU socket.  

------------------------------------------------
Please reply on list so we can share.
Off list email goes to trash, I had to due to scrapers.


Re: Setting up & alignment problems.

Alan G4ZFQ
 

I am trying to Align i-Q balance, phase lo and phase high, I have no audio,
Albert,

Check all voltages as in the manual.

73 Alan G4ZFQ


Re: Setting up & alignment problems.

Dave Edwards
 

Albert....I was in your shoes EXACTLY last night.

I never made it to the phase lo and phase high, because the I-Q balance just showed 0...or perhaps it was 1, But, either way....did not have any effect when twiddling the trimmer cap.

From the little bit of panic reading I did, I was able to guess that I should first check the 3 clock signals. Do you have a scope?

I can help you with those, but another thing to check is to buzz out with an ohm meter each of the windings of that transformer....so the start of the 38 turn winding should show a short to its' end. And similarly, each of the 5 turn windings should show a short from start to end on the circuit board.

In my case, the second winding (5 turns) did not show a short from the two pads where it should be soldered.  Too small for me to tell what the heck was going on, so I yanked the transformer, and started it over this morning. Then, it worked....and I went through the rest of the alignment, and made a contact this morning!!

On 12/10/19 2:17 PM, g4oge@... wrote:
Hi, I've built a 40 meter version of the QCX, and I am trying to Align i-Q balance, phase lo and phase high, I have no audio, and the adjustment number (top right of display) is constantly 00 wherever the volume is, I have gone over the board and re-soldered and checked for solder jumps, I checked 2 pairs of phones but no sound, not sure where to start even, any advice appreciated. Albert


Setting up & alignment problems.

Albert Rowe
 

Hi, I've built a 40 meter version of the QCX, and I am trying to Align i-Q balance, phase lo and phase high, I have no audio, and the adjustment number (top right of display) is constantly 00 wherever the volume is, I have gone over the board and re-soldered and checked for solder jumps, I checked 2 pairs of phones but no sound, not sure where to start even, any advice appreciated. Albert


Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ




Re: QCX/QSX Elmering and Discussion

Ryan Flowers
 

If you have an antenna analyzer, you can sweep a filter and get a pretty good idea of its performance. 

I documented it here:

https://miscdotgeek.com/qrp-labs-band-pass-filter-tips/
--
Ryan Flowers - W7RLF
The BITX40 FAQ


Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ



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