Hi,
Bojan yes, I just swapped the TI 74ACT08 ICs between the #1 and #3 boards. The low power fault stayed on the #3 board regardless of the TI chip. I do not have other branded chips to try. I do not think, following the transformer discovery, it is the issue.?
Yes, thank you Hans for the kind explanation. It is worth saying here that there are two separate things not correlated. At least to my understanding.
1. The issue with some QDX kits?of a few dBs lower output power on 12m/10m caused by possible stray C, toroid resonance of the output transformer T1 windings.
2. The about 1dB improvement from 20m to 10m when a different IC5 driver chip is used.
And thus the item 2 can help but is not the cure for the item 1.
73 Bojan S53DZ
