Wonderful score today

[tubesrule]

Congratulations Dave! These sets are relatively easy to restore and perform well.

Originally Posted by David Roper

Far from absolutely necessary, as the success of slope detection with the unmodified restored sets at the ETF has proven.

Dave,
The problem I've run into with slope detection, while it does work it requires the audio carrier to be centered right on the slope, meaning any slight drift in the LO and the audio moves off the slope and drops out. The RCA LO design seems to be a bit more stable than the GE, but they require constant touching up of the fine tuning the entire time you run them. The other problem is modern modulators set the audio carrier -16dB from the video whereas it was originally set to -6dB.
I've given up on slope detection since my converters are capable of AM and FM audio modulation and variable carrier level. Driving these sets with a -6dB AM signal is night and day from using slope detection. As a bonus I program the converter for 441 line and the original carrier frequencies not that this is required.

Darryl

Edit:
Steve,
You posted your reply while I was writing mine. How much drift do you notice in the sets, especially the GE's when operating them? What I found was I had to constantly touch up the fine tuning to keep the audio on the slope. With AM modulation and the fine tuning having such a limited range on these sets, it pretty much doesn't matter and the sound always comes through strong with less distortion.