Quote:
Originally Posted by Yamamaya42
Any updates/ progress with your maggie?
To quote Spock from Star Trek II : The Wrath of Khan.
https://getyarn.io/yarn-clip/79475c4...f-a2b3598a16ab
I did try to adjust the 4.5 MHz (A11) on mine again, to see if it had any impact on the slight color shadow, it did not, it DID however have a point at where it started to interfere with the color and vertical lock, but really no noticeable improvement in adjusting it other than very slight reduction of herringbone patterns when FT is off tuned.
I did however have one annoying embarrassing incident that made me had to remove the chassis yet again, after I had it all bolted back in  , while tuning A11 from extreme to extreme, I went a wee bit too far on the lower, and the damn core fell out the bottom into IF cage, I had to open it to get it out, I did not realize it would do that, I thought it would hit bottom and stop, oh well, no harm done other than a hour or so lost!   |
I have been reading the manual for my B&K 415. It has a chapter at the end that explains RF, IF, and chroma alignment for a couple models of TVs. Luckily, the first example explains the steps for the Magnavox T933 by showing the alignment steps called for by Magnavox in their OEM service manual and comparing how it is done using the B&K 415.
Both OEM alignment steps and B&K alignment steps are equally thorough. The B&K steps just involve less test equipment. It involves tuning coils and pots on the RF tuner, the IF board, and the chroma board. There is no way this can be done without a sweep and mark generator. Also, the steps in the Sams Photofacts are not as thorough as the OEM and B&K steps. The quality of the alignment wouldn’t be nearly as good if the Sams guide was used.
For example, the sweep generator sends a 400hz waveform through the RF signal and minimizing the amplitude of that in various parts of the IF circuit is how the sound traps are tuned. Much more scientific than the Sams guide. The bode plots provided also differ a bit from those in the Sams.
I noticed the same thing for Sams dynamic convergence steps, which are also inferior compared to the OEM steps. Ditto for the chroma AFC alignment which is very bad in the Sams. The hand written notes in the scanned copy of the Sams are a big improvement. Definitely makes me lose respect for Sams. OEM and B&K guides are superior.
The thing that worries me is the fact that some of the IF coils use two cores: a top core and a bottom core. Each must be separately adjusted. I have many alignment tools, but I worry that I don’t know how to “feel” my way between the top and bottom coil.
