RCA 9TC240 Alignment...The start of my education (I hope!)

[Penthode]

Hi and happy aligning. I have had experience successfully aligning this chassis for more than 50 years. It can be a challenge if you do not keep various factors in mind.

First you must have accurate marker frequencies. This is a split sound set and to achieve optimum picture quality with best sound, the marker accuracy is utmost. I use an HP5245L frequency counter with an HP 606B signal generator. Plus my favorite alignment combo is the HP8601a Sweep generator with HP8600 Digital Marker. The total net cost for all of this equipment combined was $150 and it was top of the line. There are many solutions available and all are now pretty cheap. It would be wise to review what equipment you have before you begin. Remember this set has more trap circuits than any other set! Two adjacent sound, two adjacent video, two co-channel sound, a baseband trap and an RF trap, each if misadjusted can adversely affect the video quality.

Second as this is a split sound receiver, the fine tuning control is adjusted for best sound, not best picture. If the alignment is not correct, when fine tune for best sound, the video will not look good. So it is essential as the manual advises to first proceed with the sound IF and descriminator alignment before proceeding with the video alignment.

Third, be aware the quality of the video IF amplifier tubes will affect the end result. Make sure you have fresh tubes in place you can trust. Because changing a tube in the video IF will affect the response curve.

Lastly before you start, the set uses an over coupled transformer between the tuner and first video IF stage. This is a broadly coupled link and it is essential to sweep align it. You must follow the instructions in the manual to get the curve depicted. I found it pointless to proceed unless I can get the proper response at this point because the subsequent video IF sweep adjustment will not be right.

I would suggest following the step by step process to the letter and if/when you reach a stumbling block, simply post it on the forum.