How to select resistor sizes for vintage electronics?

I ordered some 1 and 2 watt resistors I didn’t have and they came in, but a few of them seem rather small. One of the 2W is the size of a 1/2W and one of the 1W is the size of a 1/4W. Is this possible or was I potentially sent wrong wattages? I’ve attached the resistors in question next to what they’re replacing and next to known 1/2W.

Thank you for your inquiry.

You were likely sent the correct wattages for what you ordered. Resistor material composition has changed over the years where they can pack higher wattages in smaller sizes.

If you want you can take the part number you ordered and check against our website, we have the sizes of the resistors listed. We have a number of 1 Watt resistors in our system that are around 0.250 inches long (6.35mm)

Here is a TechForum post on the subject.


Thanks, for the help. They did indeed meet the size description on y’all’s website.

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Hello @ajrennspies,

You are a brave soul for working on those old tube-type television!

Some of my worst electrical shocks were from the anode of the picture tube. As I recall, the high voltage was somewhere in the 20 kV neighborhood.

Be sure to follow the discharge procedures!

As for the resistors, I would recommend moving up in size to as close as possible to the original e.g., 3W or even 5W if it will fit. It is a question of heat - we need more surface area for the heat to dissipate. While the smaller resistors will work, they can lead to hot spots on the PCB thereby accelerating damage or delamination.

Best wishes,


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