VT-73 Motorola Sound IN video?

[bandersen]

Unfortunately you wont be able to align this set with a B&K 415. The 415 is for the more modern 44 MHz IF, while the VT-71 uses the older 21 MHz IF.

Are you referring to the coil in the canister with the 1N34 detector diode ? It corresponds to A4 in the Sams alignment info. It affects the video IF curve along with A5 and A6. You'll need a sweep generator with markers and scope to properly adjust those coils.

I use a Wavetek 1002 for my alignments.

[koviatt]

Originally Posted by bandersen

Unfortunately you wont be able to align this set with a B&K 415. The 415 is for the more modern 44 MHz IF, while the VT-71 uses the older 21 MHz IF.

Are you referring to the coil in the canister with the 1N34 detector diode ? It corresponds to A4 in the Sams alignment info. It affects the video IF curve along with A5 and A6. You'll need a sweep generator with markers and scope to properly adjust those coils.

I use a Wavetek 1002 for my alignments.

I was able to get a Heathkit T-3. Wasn't aware that the B&K 415 would not drop low enough to work on these pre 50 sets. I am new to aligning TV, so its a learning curve for me in that regard. Thanks for the info on the coils. I have spent considerable time on your channel and appreciate the investment you have made for the hobby. I was hoping to find a basic alignment step by step on one of these older sets. If you have a video like that let me know - I may have missed it.

[JohnCT]

Originally Posted by koviatt

I was able to get a Heathkit T-3. Wasn't aware that the B&K 415 would not drop low enough to work on these pre 50 sets.

Not just pre 50s, but some TVs into the mid 50s used the 25mhz IF frequency as well.

I have a 1077B B&K Analyst that uses a flying spot scanner to reproduce a test pattern from a transparency at any IF frequency the dial is set for (infinitely adjustable).

For S&Giggles, I'm going to try an eyeball IF alignment on a 25mhz IF using the 1077B in the near future. If I screw it up I do have an old marker generator I can use to get it back.


John