Duncan's 1960 Magnavox - Videokarma.org TV - Video

Mr.Duncan · #1 08-09-2024, 10:51 AM

Quote:

Originally Posted by old_tv_nut

In my opinion, replacing common resistors that are in spec "just because" is a waste of time if you have operational problems that you need to get fixed, unlike certain capacitors that could be eventual failure points.
Did you know that 10% or 20% carbon composition resistors were often near the plus or minus limit of value because the production line output of a particular value covers the whole range of +/- 20% and then the 5% parts are selected, and then the 10% parts are selected from the remainder, and then the over 20% parts are culled from the final remainder? So old tube-era sets were expected to have resistors that are towards the ends of the spec and still work. The time to replace resistors "just because" is after all the real problems are fixed.

I think I may go that route "just because" once I solve the vertical circuit problem. I'm still struggling to find the error, so far all replacement capacitors are wired correctly & test correct.

When able, I've been buying higher spec replacement parts.

For example if it called for a 20% +/- tolerance I'd replace it with a 10% tolerance part capacitor. (plus slightly higher voltage rated capacitors 400 vs 630.)

As for resistors, that does make sense!

If we look at R50 for example, it should be 220 ohm @ 1watt.

Does anyone have a recommendation of what TYPE to buy?

When looking at that spec resistor with a 1% tolerance rating I have Wirewound vs Metal Film.

If I go to 5% tolerance "Metal Oxide Film" shows up.

What's best? - I really don't mind paying extra for higher quality / better parts.

options by Thomas Duncan, on Flickr