so i just picked up a 1939 CF 255. the plugs was missing and so i cu the cord to replace it ... then i noticed th blue power resister that takes up 70 of the 120 volts. what do i do to replace it? i i reconect it will it light up in flames? really freaken out I've restored 3 radio but never seen anything like this. someone help. please.

Hi

You may be referring to a line cord resistor in series with filaments? If so they dissipate a lot of power. Here is an article for what can be used in place of the resistor:

http://www.vintage-radio.com/repair-restore-information/valve_dropper-calcs.html

Norm

:so i just picked up a 1939 CF 255. the plugs was missing and so i cu the cord to replace it ... then i noticed th blue power resister that takes up 70 of the 120 volts. what do i do to replace it? i i reconect it will it light up in flames? really freaken out I've restored 3 radio but never seen anything like this. someone help. please.
:

Following up on Norm's post: Those resistive line cords are frequently called "curtain burners." They would not be sanctioned under today's codes. Best to replace with a voltage dropping ac-rated capacitor. A power resistor mounted inside the cabinet might work, but would dissipate too much heat. A dropping ac-cap won't dissipate heat.

Some of the earlier ones I've seen actually really were well built--the resistive wire was wound in asbestos, and well contained. The regular current carrying wires are encased in rubber and then cloth. The cloth protects the rubber, and also prevents shorts, should the rubber crack. The entire unit is encased in cloth.

Some of the aftermarket replacement cords are a joke, on the other hand. Two I have, for example, a JFD and a Lusturized Wire (forgot the company, but they are still in business), both use rubber insulation on the main wires, which has hardened and crumbled, and is not protected by cloth (at least if you are going to hide rubber insulation from view, protect it with something else so that if it rots, it doesn't allow a short). One has the resistive wire wrapped around some fiberous material, possibly asbestos, and this lies right next to the regular wires. This cooks the rubber insulation on the regular wires and eventually melts through, or touches the wires when the insulation cracks. The other has the resistance wire wound around one of the regular wires with loose strands of cloth in between. In both cases the resistive wire made its way through to one of the regular wires, causing a short and a burn-up of the resistive wire. This also could blow the tubes in the set.

...Some of the older OEM cords I've seen were well constructed, however, and I did not see them causing problems so long as they weren't completely rotten.

...best to replace with capacitors anyway, though, unless the cord is in really good condition.

:Some of the earlier ones I've seen actually really were well built--the resistive wire was wound in asbestos, and well contained. The regular current carrying wires are encased in rubber and then cloth. The cloth protects the rubber, and also prevents shorts, should the rubber crack. The entire unit is encased in cloth.
:
: Some of the aftermarket replacement cords are a joke, on the other hand. Two I have, for example, a JFD and a Lusturized Wire (forgot the company, but they are still in business), both use rubber insulation on the main wires, which has hardened and crumbled, and is not protected by cloth (at least if you are going to hide rubber insulation from view, protect it with something else so that if it rots, it doesn't allow a short). One has the resistive wire wrapped around some fiberous material, possibly asbestos, and this lies right next to the regular wires. This cooks the rubber insulation on the regular wires and eventually melts through, or touches the wires when the insulation cracks. The other has the resistance wire wound around one of the regular wires with loose strands of cloth in between. In both cases the resistive wire made its way through to one of the regular wires, causing a short and a burn-up of the resistive wire. This also could blow the tubes in the set.
:
:...Some of the older OEM cords I've seen were well constructed, however, and I did not see them causing problems so long as they weren't completely rotten.
:
:...best to replace with capacitors anyway, though, unless the cord is in really good condition.
: