Evan,
Really appreciate your help and info.
Will try again to make sure toroids are good
and check the diode voltages.
One problem I have is identifying? right
solder point on bottom side of board, since it is so crowded.
Will advise with results.
Thank you? 73
Emory? WM3M
On 3/13/2024 1:48 AM, Evan Hand wrote:
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Hello Emory,
12, 11, and 10 meters share the same low pass filter (LPF).? This
would point to a problem there.? The most common is one of the
toroid connections did not burn through the enamel.? This assumes
that the configuration is correct.? I suggest the following:
1 - Update to the latest firmware from the QRP-Labs web page:?
2 - Do a factory reset
If the above does not solve the issue, then:
3 - Verify that the LPF diode selection is working correctly.?
This also verifies that the toroid connections are good, as the
toroids are used to conduct the DC bias.? The LPF diodes are D508
through D513.? D510 and D513 select the 12/11/10 meter LPF.? The
banded end (Cathode) should be close to 0 volts.? The other four
should be close to the supplied voltage to the QMX.? This test is
while receiving, not transmitting.
The next steps would depend on your findings from the above.?
Please post your results, including the version of the firmware.
73
Evan
AC9TU
