TV IF alignment

[DaveWM]

well I just realized my 415 has a horz seep norm/reverse for the trigger, so I just need to get a cable to hook it up to the external sweep and I should be able to reverse that image.

[DaveWM]

did the hookup of the to horz on scope, rev and normal did not reverse the image, just moved it over, oh well, not a big deal I just wanted it to look like the display on the the 415.... guess I could look at the scope or the 415 in a mirror...

will be hooking it up to another tomorrow, again same chassis just anohter TV so hopefully I can make a pretty much direct comparison, I will leave all the settings alone (bias,sweep,amplitude) and just compare IF strip to IF strip. I hope the next tv has a slightly better curve/marker profile, that way I will know I am getting the correct results. If they match this one, then I have to wonder if I am setting it up right, since a match to the same wrong profile may mean I am detuning something with the hook ups.

[DaveWM]

another set, this time with the injection point being the Osc tube with a ungrounded shield. I added a 44mhz marker, shown in the center of the two main humps

The second from the right is the picture marker, the far right are the two audio markers, there is supposed to be a small hump there, but you cant see it at the bias setting I am using to keep from flattening out the two main humps.

[DaveWM]

I am learning about this OJT, the TP was right next to a IF coil, actually INSIDE the can (removable shield). the shield alone would drasticly effect the tuned response as would the TP leads etc (this is for the demodulated IF signal). Anyway care must be taken for lead dress when hooking up to these TP's.

[DaveWM]

here is the Emerson, the 1st pic is the B&K 415 setup with various markers set, the second is the IF curve.

note due to the sweep direction of my scope the IF curve is a mirror image of the curve plottted out on the B&K.

The picture marker on the B&K (middle of slope on right side) is present on the IF curve (middle of slope left side) its just not easy to see.

[DaveWM]

after consulting with a bud from another forum, I may try touching up the traps to get the bottoms a little closer to the markers. I hooked up the set to the cable and I get a bit of interference. I am guessing its ajacent channel noise that was not an issue with the DVD player. I am able to tune the VHF band ok, but the interference looks sorta like herringbone patterns (like it needs fine tuning but the fine tuning only gets it so far).

[DaveWM]

oh and subing out IF tubes can make big changes in the size of the humps, I could swap 2 IF tube and reverse those gain diff indicated by the size of the two humps.