What is the correct type of pot for the focus control?
The sams states 100K 2W wire wound part.

The set has a carbon pot installed in it and I'm not sure if it is factory or not.
The focus on my set is a little soft and a snapping sound is heard if you mess with the control.

The control tested good out of circuit.

Is the sams a mistake or do I need to track down a wire wound pot?

Seems to me that 100K would be rather high for a wirewound pot. I should think it would be carbon at that resistance. I dont have a RCA print for CTC9 so someone else with a RCA print will need to weigh in on what the actual spec is for that pot.

:scratch2:Seems to me that 100K would be rather high for a wirewound pot. I should think it would be carbon at that resistance. I dont have a RCA print for CTC9 so someone else with a RCA print will need to weigh in on what the actual spec is for that pot.

I think that's another Sams Snafu!
100K WW pot? What kind of wire would the thing be wound with? :scratch2:

RCA field service guide shows 100K, RCA# 105808A (wattage not given).
Phil

Seems to me that 100K would be rather high for a wirewound pot. I should think it would be carbon at that resistance. I dont have a RCA print for CTC9 so someone else with a RCA print will need to weigh in on what the actual spec is for that pot.

It's not like the don't exist. :o
Digi-Key Part Number:534B1104JC-ND
I was able to find a 100K WW at 2w rather quickly :o
So, who knows. :p

but you are Prob right, and its carbon.

What is the correct type of pot for the focus control?
The sams states 100K 2W wire wound part.

The set has a carbon pot installed in it and I'm not sure if it is factory or not.
The focus on my set is a little soft and a snapping sound is heard if you mess with the control.

The control tested good out of circuit.

Is the sams a mistake or do I need to track down a wire wound pot?
Remove it and take it apart. See if there's carbon tracking inside.
I looked up the schematics on the CTC7,9 and 10. The CTC7 shows a pot as well as the CTC9, the 10 and newer has a coil.
The CTC7 only shows an RCA part number. :scratch2:

It's not like the don't exist. :o
Digi-Key Part Number:534B1104JC-ND
I was able to find a 100K WW at 2w rather quickly :o
So, who knows. :p

but you are Prob right, and its carbon.

Why would you need a WW? No current, just a potential!

But look where it is. It's not getting a lot of power, but it is across part
of the flyback. Hence, its getting a big voltage pulse so one thing that matters
a lot is the peak voltage rating. Is the case grounded or carefully floated at over
a kV? The DC on it is the boost voltage.

more confusing
https://www.onlinecomponents.com/cornell-dubilier/m100mpk-45184738.html
https://www.ebay.com/p/Mallory-Potentiometer-4-Watt-M100MPK/1534170311
Part # M100MPK as shown on SAMS can still be found, (not cheap) and is ww :o
no hits on search for the RCA # 105208A though. :(

As a bit of confirmation, the SAMS for the ctc7 is close to the ctc9 also has the same POT, and is shown to be a wire wound, and even lists the SAME RCA part # 105208A , so chances are it SHOULD BE wire wound, as shown in the SAMS, but my guess is as good as anyone's :/

RCA field service guide shows 100K, RCA# 105808A (wattage not given).
Phil

The omnibus shows it as a 105208a, I'll look but I don't think I have any new ones left.

The omnibus shows it as a 105208a, I'll look but I don't think I have any new ones left.

The one I found on EBAY seems new, but $40 seems rather inflated to me for the part :(