This morning I went through the freq display adjustment and evaluation with much more care than the first time, when I originally discovered the trimmer control.

Perhaps initially I didn't leave the radio on long enough for the circuitry to warm up completely, because now I find ZERO imbalance between LSB and USB across HF and medium wave. Probably someone with test equipment could find something wrong, but to my ears the sound is identical between sidebands when the filter bandwidth is the same, the radio is tuned to the carrier, and the PBT is centered.

As far as frequency display accuracy, I now have the display spot-on throughout the HF range, and only 20 Hz error near the bottom of medium wave. That is, zero beat on my local on 570 kHz needs to be set to 570.02 kHz for natural speech in LSB and USB (which still sounds "balanced between LSB and USB at 570.02). For my local on 1000 kHz, I need to tune to 1000.01 kHz for zero beat, and on 1560 kHz the zero beat point is right at 1560.

The radio is quite stable enough for pleasant and useful ECSS tuning of DX after the warm-up, which is quite an accomplishment for a portable receiver!

I now want to investigate how long it actually takes for the drift to settle down, as I left the radio on over night before doing my more careful adjustment and test.

BTW, just to clarify my earlier message, the frequency adjustment hole is found in the copper cover that's beneath the left slot OF THE RIGHT GROUP of ventilation holes on the back. It is *not* under the very far left vent slot.

Guy Atkins
Puyallup, WA
www.sdr-1000.blogspot.com