05-06-2011, 07:43 PM
Ok let's start at the beginning. Start by aligning the IF at 470KC. Hook your generator to the cap on the 6A7&chassis ground. Take an analog ac volt meter, hook it across the speaker terminals. Set it on the lowest ac range.Let the set and generator warm up for15 mins or so. With the generator set to 470kc and 400cy modulation listen for the signal with the volume up half way or more. Set the output level of the generator at the lowest level that you can get a reading on the ac volt meter.
Now you are all set up to align the IF transformers. Rap a small bit of tape around the tip of your screwdriver blade exposing only about a 1/16 of an inch of the blade. Some sets have B+ on the IF trimmers(plate side) so you don't want to short the B+out. Start with the IF can close to the 6A7. Adj both trimmers for highest reading on the ac meter. Go to 2nd IF can and do likewise. As you peak the trimmers adj signal level down to the minamon
reading on the meter.
Sometimes there is a bit of interaction between the two transformers so replete the adjustment. After you've done this your IF's are done. Don't go back and readjust the trimmers "best sound" or "it plays louder" or any other reason.
Dare I ask, has this set been serviced? New caps and such?
Terry
Now you are all set up to align the IF transformers. Rap a small bit of tape around the tip of your screwdriver blade exposing only about a 1/16 of an inch of the blade. Some sets have B+ on the IF trimmers(plate side) so you don't want to short the B+out. Start with the IF can close to the 6A7. Adj both trimmers for highest reading on the ac meter. Go to 2nd IF can and do likewise. As you peak the trimmers adj signal level down to the minamon
reading on the meter.
Sometimes there is a bit of interaction between the two transformers so replete the adjustment. After you've done this your IF's are done. Don't go back and readjust the trimmers "best sound" or "it plays louder" or any other reason.
Dare I ask, has this set been serviced? New caps and such?
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry