About Adjusting 4.5 mc trap/Sound Take-off in a Single Coil Can??

[Jon1967us]

I fairly new to alignment and am trying to perform one on a TV video/sound panel on a '59 Philco TV.

The schematic and alignment instructions indicate that there's a "top" adjustment for the 4.5 MC trap and a "bottom" adjustment for the "sound take-off"

So, am I to understand that I need to access the bottom adjustment from under the dual coil can (which means that I need to undertake to remove the staked circuit board, which isn't a small undertaking) or am I missing something?

Also, it appears my other needed adjustment includes a 4.5 MC IF Interstage transformer. However, it appears that the unit is damaged, as I can't seem to probe and find the adjustment screw inside. I think it broke off from overzealous adjustment long ago (?)

Can the transformer be repaired or do I need to just locate a new one? Are all 4.5 IF transformers pretty much equal in value and it's just a matter of matching size, board mounting specs?

Thanks for any help!!!

[Electronic M]

If the coil has an Allen key style slug in it you then you keep the board mounted and you get a special plastic diddle stick that has the Allen key on the on the end and a skinnier round shaft above....you push the tool into the top slug then keep going down till it disengages with the top and then you feed it into the bottom slug....these were common in the 50s and 60s and I find them in service caddies periodically...

Some coils use a flathead screwdriver style adjustment and some use an Allen key adjustment... whichever you have ALWAYS only use plastic adjustment tools. Metal alignment tools will crack the slugs and also change the tuning so if you tune a coil with a metal tool the instant you remove the tool the tuning will shift.

Also unless you have a working sweep/marker generator and a scope DON'T touch the video alignment it is close to impossible to get it right by eye.

[Notimetolooz]

For obvious reasons all adjustments should be done with the power applied and the set working.
There are fewer places to find the tuning wands or sticks. Some call them diddle or tweeking sticks.
This link at least gives you a fairly good picture of what is needed.
Be aware that some are made from a poor type of plastic.
Never turn them very hard, the ferrite tuning core in the coils is very brittle.
If you had worked on vintage radios you probably would have come across this situation before. You can carve sticks with a screwdriver blade ends by using wood chopsticks. Hard to make ones with hex ends.
https://www.amazon.com/Philmore-Univ...s%2C221&sr=8-5

[Jon1967us]

Originally Posted by Electronic M

If the coil has an Allen key style slug in it you then you keep the board mounted and you get a special plastic diddle stick that has the Allen key on the on the end and a skinnier round shaft above....you push the tool into the top slug then keep going down till it disengages with the top and then you feed it into the bottom slug....these were common in the 50s and 60s and I find them in service caddies periodically...

Some coils use a flathead screwdriver style adjustment and some use an Allen key adjustment... whichever you have ALWAYS only use plastic adjustment tools. Metal alignment tools will crack the slugs and also change the tuning so if you tune a coil with a metal tool the instant you remove the tool the tuning will shift.

Also unless you have a working sweep/marker generator and a scope DON'T touch the video alignment it is close to impossible to get it right by eye.

Thanks for the useful info. The dual coil has a hex lug, at least on the top. Should I assume the bottom lug/the lug directly below is the same size and is also a hex?

I have the Philmore alignment set and unfortunately it's total junk. The plastic is as soft as butter. I've gone ahead and ordered this set, as tools 3rd from left and 2nd from right look to be the appropriate ones and I need a better general set.

Otherwise, I suppose I could fashion something.

As far as the other mashed IF can, I've ordered another NOS one to replace. Hopefully the voltage rating will be sufficient.

[Electronic M]

Typically if one core is a standard hex size then both will be. Makers were usually consistent about that...if they are not then it is possible someone switched out a slug aftermarket.

It is possible to replace the slug with another the same length (or another ground down to length) I tend to buy up disembodied convergence boards to steal convergence rheostats coils and slugs off of as well as hoard NOS and and used tuned coils from parts sets so I can repair and replace things.

[Notimetolooz]

A little tip about using the flat screwdriver type of adjustments that are metal screws as in trimmer caps and radio IF cans that use a variable capacitor. You can use a regular metal screwdriver, with the power off, first to free up the screw. The plastic tool blades will be chewed up by a stuck screw.
Sometimes the hex core slugs will be a bit stuck also and occasionally the manufacturer put a bit of wax or similar to hold the slug in place after they adjusted them. CAREFULLY using an Allen wrench first, again power off, might work. Be aware that some coils have mechanical stops at the ends of the adjustment range.

[Jon1967us]

Great, helpful info, guys. Much appreciated.