Ok. Let’s try this again…RCA 9TC240 Alignment

[Chris K]

Originally Posted by Penthode

The resistors temporarily shunting the coils will essentially make the IF amplifier downstream a broadband untuned amplifier. This will allow you to see only the tuner to first IF over-coupled link frequency response without interference. You want to be able to establish a correct response between tuner and first IF before adjusting the remaining stages. So the order of work is:

1. Confirm traps are correct
2. Sweep align the tuner to first IF over-coupled link with resistors shunting the downstream stages
3. Sweep align the entire video IF with the resistor shunts removed.

You should be cognizant of the fact that unless someone has in the past meddled with the tuner-1st IF link transformers, the adjustment should be close. Be aware that if any of the resistors are not connected or loose, it will distort the response you are trying to obtain.

Once the resistors are removed which will raise the gain of the IF amplifier, there is the danger of oscillation which they describe how to handle in the notes. The oscillation will occur if two of the stages are tuned close to the same frequency. The Video IF stages must be properly stagger tuned to be stable.

Here is a Wiki page describing stagger tuning.

https://en.wikipedia.org/wiki/Stagge...reduced%20gain.

Thank you. I have not messed with T-1 and T-101 so hopefully they are close. Still not clear on where to clamp the resistors...for example, on T-102, I am putting the resistor between tabs A and B correct? I'm not shunting the trap coil correct?

[Penthode]

A caution I need to add with this particular chassis when adjusting the IF stages. The adjustments can be deceptive because when you are adjusting for a peak you may inadvertently be tuning two stages to the he same frequency which will cause oscillation. This oscillation can be easily mis identified as a peak. The way to confirm is always as you raised or lowered the deep generator input, the output put level should rise and fail. If when reducing the signal generator in you still see a signal which does not change when you vary the generator output, you have an oscillation condition you will need to address.

[Chris K]

Yes as you have said. Not gonna tell me which coil gets the shunt eh?? That’s ok…I’ll figure it out!

[Penthode]

Originally Posted by Chris K

Yes as you have said. Not gonna tell me which coil gets the shunt eh?? That’s ok…I’ll figure it out!

I told you! Even down to the connection letters written on the base of the transformers!