I'm aware of that.? Have done it as well.

Also it depends on bias setting and the winding of the transformer.
By that I mean how tight and careful both windings are done.

I look at it as interesting but, what use is it beyond diagnostic
if ian amp is not developing full power as then the transformer can
be ruled out or not.

I have done the reverse on a board without finals loaded and the
Drain to Source path with R/C to simulate active devices to test
if the transformation of the transformer is valid.? I use that more
at VHF and up amp designs.? Same for input transformer or
matching save for the simulated load will match the gate to source.

As to input impedance, its nice to know but it was never meant to
be 50 ohms.? Again it can check the transformer.? FYI the QSX design
the driver was power limited but not voltage swing limited so higher
input impedance was needed.? That was the design source (QSX).

The test fixture I use verifies the assembly is flat and has known?
(measured loss) as that is a full two port test then the DUT(amp or other)
is added.? Since it build it up and measure the rare case is I find a
bad attenuator or cable early in the process.

--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.

I yanked some bristles out of a wire brush but the steel stuck in the solder! I have some bamboo sticks that might be worth a try...
--
73
Karl
KI4ZUQ

Despite the lack of a backlight, my computer recognized the QMX, so I installed the firmware and it worked (even got a backlit display).? Maybe the processor thought I was in firmware update mode rather than initial setup mode?

Setup and testing will continue tomorrow.

Thanks again, Ludwig,
Eric

Thanks Gary. Unfortunately this issue appears with and without the knobs. I guess if I’m going to figure this out I’m going to need to become friends with the schematic and try to reason out what in changing to “Digi” mode could cause this “noise” to appear at the audio port.

It sounds almost like it would when you picked up the phone while your 14.4K modem was active on the line.

One possible problem is the cable has 75ohm connectors...? BNC connectors for the different
impedance due to dimensions of the plastic insert and the pin.? Both parts must match.

That and come cheap prefab cables are just crap.

--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.

开云体育

Same experience here - leave the nut, but the lock washer prevents any BNC from fully seating. This has been true for 6 out of 6 rigs built by me. Sandy KB3EOF

Matt,
I had a similar problem with my QMX when I had metal knobs on the encoders. An ESD event from my finger would cause the screeching. Try grounding yourself before touching the QMX ( I am assuming you don't have any knobs on the QMX yet and are just turning the encoder shafts)
Gary
W9TD

I ordered a OCX-mini 20 meter and had it built by QRP as I don't solder. Finally tried to connect coax and the connector will not close all the way. Same problem with a dummy load. So the unit is useless, see attached jpg to see the problem, notice the part I have circled in blue. I've seen another ops ocx-mini and the bnc connector doesn't look like the one on my unit.

On Fri, Feb 23, 2024 at 05:12 PM, Bob W7DIT wrote:

with a toothpick

I'm using a steel fixing pin. The pin takes no solder. Maybe you should grind a bit from the tip.

73, Ludwig

So I tried it and it worked fine, same transmit power as my 12v battery (3.2w on 40m) .?

No issues whatsoever.?

On Fri, Feb 23, 2024 at 08:49 PM, Eric W. Hansen wrote:

and push the button on the rotary encoder

Hi Eric,
I did this yesterday at my 2nd QMX (20 m - 10 m) and it worked.

Wish you success.

73 Ludwig

开云体育

Thanks, Ludwig, good question.? The ViFly, with no load connected, registers 40mA on my bench supply's meter, same as with the QMX connected.? This implies that the QMX isn't drawing anything, so I can now increase the current limit on the supply and push the button on the rotary encoder.

Eric

Thank you Adrian.?

The IQ mode is not enabled. Also, I tried a factory reset but the issue remains.

73, Matt

I really do not want to drill them, either. So, you actually got them to clear with the solder wick?

"I soldered a capacitor in the wrong place on one of my kits and managed to successfully remove it and get the holes cleaned out. I used solder wick with a little flux, but I first added some fresh solder to the holes to give the solder wick something to grab on. I had to do it a couple of times on one hole, trying from both sides, but it worked."

I will try your technique, first. Thank you!
--
73
Karl
KI4ZUQ

I am looking for an OHR Explorer II from the 1990s.? Does anyone have one ?

My guess is that this is a firmware bug.
My QMX Low Bander does the same thing if I leave it on over night.

Hans is making great progress though with all the updates:)!

Hello,

Isn't the "IQ mode" setting in the "Digi interface" menu enabled, by any chance?
If not, you may also try a factory reset.

Regards,
YO3GFH
op. Adrian