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Re: Blocking a band on QMX/QMX+

 

Ah! Great info. Thanks a lot.



15 Oca 2025 ?ar 05:58 tarihinde Stan Dye via <standye=[email protected]> ?unu yazd?:

The screen scrolls to the higher bands.
Move the cursor across to the right and keep going.


Re: Blocking a band on QMX/QMX+

 

The screen scrolls to the higher bands.
Move the cursor across to the right and keep going.


Re: Blocking a band on QMX/QMX+

 

Nope. It is configured for 160-6 but there are no values listed in the manual under Putty's Band Configuration menu, except for 5 bands. Seeing the post on how to block certain bands, I am concerned my rig will not work on the unlisted bands.



15 Oca 2025 ?ar 05:07 tarihinde Ronald Taylor via <wa7gil=[email protected]> ?unu yazd?:

Bekir, it sounds like you may have your radio configured as an 80-20 meter QMX instead of as a 160-6 meter QMX+.?

Ron

On Tue, Jan 14, 2025 at 19:01 ta2rx bekir via <ta2rx.bekir=[email protected]> wrote:
I want to do the exact opposite of this. I want to be able to use my QMX+ on all bands, especially the upper bands. However there are no values listed for bands higher than 20m in the Band Configuration menu. That is why I asked what the ideal values should be on 6, 10 and 15m but could not get any answer so far.

73!
de Bekir TA2RX


14 Oca 2025 Sal 18:05 tarihinde Bill via <bill=[email protected]> ?unu yazd?:
Larry,

???? An old post to this forum (that I can't find now)?recommended that in the PuTTY Band Configuration screen, you change the band's "Band Name" to 0 (zero).? I've done this and it works.? It eliminates the band when you switch the band switch from the front panel.

?
Bill
W2EB
East Syracuse, NY

On 1/13/2025 at 4:13 PM, Larry Christensen via <larryna0f@...> wrote:
I would like to block out the bands I don’t use.?

I asked this once before but never got an answer on how to do it if it is possible.?
That would make moving though the bands I do use much easier and faster.?

TIA
Larry NA0F


Re: Blocking a band on QMX/QMX+

 

Bekir, it sounds like you may have your radio configured as an 80-20 meter QMX instead of as a 160-6 meter QMX+.?

Ron

On Tue, Jan 14, 2025 at 19:01 ta2rx bekir via <ta2rx.bekir=[email protected]> wrote:
I want to do the exact opposite of this. I want to be able to use my QMX+ on all bands, especially the upper bands. However there are no values listed for bands higher than 20m in the Band Configuration menu. That is why I asked what the ideal values should be on 6, 10 and 15m but could not get any answer so far.

73!
de Bekir TA2RX


14 Oca 2025 Sal 18:05 tarihinde Bill via <bill=[email protected]> ?unu yazd?:
Larry,

???? An old post to this forum (that I can't find now)?recommended that in the PuTTY Band Configuration screen, you change the band's "Band Name" to 0 (zero).? I've done this and it works.? It eliminates the band when you switch the band switch from the front panel.

?
Bill
W2EB
East Syracuse, NY

On 1/13/2025 at 4:13 PM, Larry Christensen via <larryna0f@...> wrote:
I would like to block out the bands I don’t use.?

I asked this once before but never got an answer on how to do it if it is possible.?
That would make moving though the bands I do use much easier and faster.?

TIA
Larry NA0F


Re: QMX+ over-voltqge?

 

After the initial fifteen seconds of 13.8 volts, I switched to 12 volts. Maybe I should try 9 volts.

Dave K9SW

On Jan 14, 2025, at 5:49?PM, Chuck Harris via groups.io <cfharris@...> wrote:

Have you tried 12.0V?

-Chuck Harris, WA3UQV


On Tue, 14 Jan 2025 16:54:49 -0600 "K9SW via groups.io"
<K9SW@...> wrote:
Thanks, Chuck. I’ve tried many variations, factory reset, restarts,
using SWR meter and dummy load, so no high SWR concerns. Still no
output or input. I’ll work on it some more and see what else happens.

It came from Mugla with the sheet listing all the power outputs on
each band, so it was transmitting at one time.

73,

Dave

On Jan 14, 2025, at 6:37?AM, Chuck Harris via groups.io
<cfharris@...> wrote:

The QMX has a protection circuit that will shut off
the transmitter if the supply voltage is dangerously
high, or too low.

It will warn you by flashing the battery symbol on the
front panel.

I don't know if it is right, but if my QMX+ shuts the TX
down for high VSWR, it loses sidetone too.

The sidetone and the TX power won't come back until you
cycle the radio off and then back on.

Perhaps, the same is true for over voltage shutdown?

Try strapping on a dummy load, applying 12.0V cycling the
power, and see if your sidetone comes back.

The radio is not amused by over voltage, or over VSWR,
but it usually, it will survive if the insult isn't too
bad.

In any case, automotive batteries, and automotive chargers
are verboten for the QMX. It doesn't want to see anything
over 12.0V (9.0V if it was built for 9V).

-Chuck Harris, WA3UQV


On Mon, 13 Jan 2025 18:23:21 -0600 "K9SW via groups.io"
<K9SW@...> wrote:
Hello all.

I bought a built QMX, being in my early 80s and not quite up to
building a complex QRP Labs kit. When it arrived, I unpacked it
and plugged in the PS IO use for the K3. Looking at the panel, I
saw the blinking battery symbol and after some rtfming, plugged in
a 12 VDC PS. However, the QMX+ has major problems, some as quirky
as a sidetone which is sometimes there, sometimes not, and major
problems such as it does not receive or transmit any RF energy
(and it’s not in practice mode). Would ten seconds of 13.8 volts
cause this amount of disfunction?

Thanks,

Dave K9SW
















Re: Blocking a band on QMX/QMX+

 

I want to do the exact opposite of this. I want to be able to use my QMX+ on all bands, especially the upper bands. However there are no values listed for bands higher than 20m in the Band Configuration menu. That is why I asked what the ideal values should be on 6, 10 and 15m but could not get any answer so far.

73!
de Bekir TA2RX


14 Oca 2025 Sal 18:05 tarihinde Bill via <bill=[email protected]> ?unu yazd?:

Larry,

???? An old post to this forum (that I can't find now)?recommended that in the PuTTY Band Configuration screen, you change the band's "Band Name" to 0 (zero).? I've done this and it works.? It eliminates the band when you switch the band switch from the front panel.

?
Bill
W2EB
East Syracuse, NY

On 1/13/2025 at 4:13 PM, Larry Christensen via <larryna0f@...> wrote:
I would like to block out the bands I don’t use.?

I asked this once before but never got an answer on how to do it if it is possible.?
That would make moving though the bands I do use much easier and faster.?

TIA
Larry NA0F


Re: QMX+ Toroids - To Glue or Not To Glue?

 

Great visual guide to soldering.? Thanks for posting !
Jim WB4ILP?


Re: Shack Clock build

 

Nice work and very Cool !
Jim


Re: Problem with 50 Watt amp for QCX

 

Bernie Poskus, KF0QS via groups.io <hamdan@...> wrote:

The current draw measurement is 74 MA.? Unfortunately, the current draw
never changes even when I turn R5 fully clockwise.
Never turn it fully clockwise. If there was an intermittent connection and
it accidentally went away, you'd destroy the finals.

What is the voltage at the output of the linear regulator (78L05) when
amplifier is keyed (but not transmitting)?


Re: QMX, one of op-amps self-oscillates at 25 MHz (or picks up the system clock?)

 

Adam via groups.io <qrp-labs@...> wrote:

I'll order 5351, hopefully I'll be able to solder it without damaging
everything around. I hope it will fix the problem (or we'll be back at
square one)...
Here's a follow-up.

I ordered SI5351A, this one:



It wasn't easy to replace, but I managed to do it without causing any
damage.

The radio works like new. No buzzing, good reception.

It might be worth adding this info to some FAQ, or at least to:



in case someone has a similar problem in the future -- which is possible,
as I didn't stress the radio, it seems the chip failed on its own.

Thanks again for pointing me in the right direction with false readings of
my scope!

73,
Adam


Re: QMX+ over-voltqge?

 

Have you tried 12.0V?

-Chuck Harris, WA3UQV


On Tue, 14 Jan 2025 16:54:49 -0600 "K9SW via groups.io"
<K9SW@...> wrote:
Thanks, Chuck. I’ve tried many variations, factory reset, restarts,
using SWR meter and dummy load, so no high SWR concerns. Still no
output or input. I’ll work on it some more and see what else happens.

It came from Mugla with the sheet listing all the power outputs on
each band, so it was transmitting at one time.

73,

Dave

On Jan 14, 2025, at 6:37?AM, Chuck Harris via groups.io
<cfharris@...> wrote:

The QMX has a protection circuit that will shut off
the transmitter if the supply voltage is dangerously
high, or too low.

It will warn you by flashing the battery symbol on the
front panel.

I don't know if it is right, but if my QMX+ shuts the TX
down for high VSWR, it loses sidetone too.

The sidetone and the TX power won't come back until you
cycle the radio off and then back on.

Perhaps, the same is true for over voltage shutdown?

Try strapping on a dummy load, applying 12.0V cycling the
power, and see if your sidetone comes back.

The radio is not amused by over voltage, or over VSWR,
but it usually, it will survive if the insult isn't too
bad.

In any case, automotive batteries, and automotive chargers
are verboten for the QMX. It doesn't want to see anything
over 12.0V (9.0V if it was built for 9V).

-Chuck Harris, WA3UQV


On Mon, 13 Jan 2025 18:23:21 -0600 "K9SW via groups.io"
<K9SW@...> wrote:
Hello all.

I bought a built QMX, being in my early 80s and not quite up to
building a complex QRP Labs kit. When it arrived, I unpacked it
and plugged in the PS IO use for the K3. Looking at the panel, I
saw the blinking battery symbol and after some rtfming, plugged in
a 12 VDC PS. However, the QMX+ has major problems, some as quirky
as a sidetone which is sometimes there, sometimes not, and major
problems such as it does not receive or transmit any RF energy
(and it’s not in practice mode). Would ten seconds of 13.8 volts
cause this amount of disfunction?

Thanks,

Dave K9SW












Problem with 50 Watt amp for QCX

 

Dear Folks:
?
I have finished building the 50 watt amplifier kit for the QCX.? I am trying to run the test on page 66 of the manual which simply requires you to do the following:
?
1)? Make sure that the R5 potentiometer is fully counterclockwise.?
?
2)? Put the QCX in "Practice" mode so no RF is generated, but the radio will generate a voltage to key the amplifier.
?
3)? After keying the amp via the QCX, measure the current draw between the amp and its power supply.
?
4)? Once you have keyed the amplifier via the QCX and measured the amp's current draw, R5 is gradually adjusted clockwise until the current draw begins to rise.? Once you see the current draw rise, you turn R5 back to the level just below the point at which the current draw rises.? That is the correct setting for R5.
?
I have done all of these procedures.? I should mention that the green "on" light comes on when power is supplied to the amp and that the red TX light comes on when I key the QCX.? The current draw measurement is 74 MA.? Unfortunately, the current draw never changes even when I turn R5 fully clockwise.
?
I should mention that I did try the same measurement with the QCX practice mode turned off, i.e., the QCX would now be generating RF.? At that point I found that turning R5 gradually changed the current draw from about 97 MA to about 103 MA.? However, no RF is generated (though the QCX generates about 4 watts when it runs barefoot).? This makes me think that R5 is functional.
?
Does anyone have any suggestions for locating the problem?
?
Thanks and 73 de Bernie, KF0QS


Re: QMX+ over-voltqge?

 

Thanks, Chuck. I’ve tried many variations, factory reset, restarts, using SWR meter and dummy load, so no high SWR concerns. Still no output or input. I’ll work on it some more and see what else happens.

It came from Mugla with the sheet listing all the power outputs on each band, so it was transmitting at one time.

73,

Dave

On Jan 14, 2025, at 6:37?AM, Chuck Harris via groups.io <cfharris@...> wrote:

The QMX has a protection circuit that will shut off
the transmitter if the supply voltage is dangerously
high, or too low.

It will warn you by flashing the battery symbol on the
front panel.

I don't know if it is right, but if my QMX+ shuts the TX
down for high VSWR, it loses sidetone too.

The sidetone and the TX power won't come back until you
cycle the radio off and then back on.

Perhaps, the same is true for over voltage shutdown?

Try strapping on a dummy load, applying 12.0V cycling the
power, and see if your sidetone comes back.

The radio is not amused by over voltage, or over VSWR,
but it usually, it will survive if the insult isn't too
bad.

In any case, automotive batteries, and automotive chargers
are verboten for the QMX. It doesn't want to see anything
over 12.0V (9.0V if it was built for 9V).

-Chuck Harris, WA3UQV


On Mon, 13 Jan 2025 18:23:21 -0600 "K9SW via groups.io"
<K9SW@...> wrote:
Hello all.

I bought a built QMX, being in my early 80s and not quite up to
building a complex QRP Labs kit. When it arrived, I unpacked it and
plugged in the PS IO use for the K3. Looking at the panel, I saw the
blinking battery symbol and after some rtfming, plugged in a 12 VDC
PS. However, the QMX+ has major problems, some as quirky as a
sidetone which is sometimes there, sometimes not, and major problems
such as it does not receive or transmit any RF energy (and it’s not
in practice mode). Would ten seconds of 13.8 volts cause this
amount of disfunction?

Thanks,

Dave K9SW








Re: QMX+ reliability

 

Mike,
?
?
plus: in a big forum like this one, you mainly hear the squeaky wheels ;) And in most cases, the squeakiness is due to builders' mistakes (admittedly, modulo the few mysterious PCM1804 failures, as pointed out earlier).
?
The QMX+ is an excellent, unique rig.
?
My2Cents
?
72/73 de M0KTZ
?


Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.

 

Thanks Don,
?
This is new information to me. I did not look beyond the red and black pairs. I did think about color coded wires. I am using 14 gage red and black wire. Those other combinations would help.
?
In this list of messages is a fresh new assertion that the QMX will absolutely puke with more than 12.0 volts applied. Maybe some day I will change my mind but for today I will avoid any "12 volt" radio that puny.
?
Onward with the QCX and other tough radios.
?
73,
?
Bill ?KU8H
?


SSB progress.

 

How is the SSB progress going? Can't wait!


Re: Best QMX AGC settings?

 

BTW here's a good thread on the subject: /g/QRPLabs/message/121907
I'm still searching for the perfect AGC settings lol.


Re: QCX+ Build Problems

 

How much current is flowing on the 12v line? If very little then maybe the regulator?is bad. If a lot of current is flowing and the regulator is getting hot, then there is a short on the 5v line. Please verify which is the case. Also look at the soldering on the pins of the regulator


On Tue, Jan 14, 2025 at 12:52?PM Martin AC1LL via <mshell52=[email protected]> wrote:
Thanks for this.? I saw that the on/off switch was not well soldered. Fixed that, Now the LCD lights up, but no text (tried turning R47 to no avail).? I read 12v between the input of the regulator and ground, but 0v between ground and the output.


Re: QCX+ Build Problems

 

Thanks for this.? I saw that the on/off switch was not well soldered. Fixed that, Now the LCD lights up, but no text (tried turning R47 to no avail).? I read 12v between the input of the regulator and ground, but 0v between ground and the output.


Re: QMX+ reliability

 

The only issue thats in the "shadows" and not explained is dead pcm1804 IC either on first poweup/DOA or during the use. My qmx+ was in this group. After replacing the IC no issues.?
Other issues are mostly solved and related to assembly/operator/antenna errors.