Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dpm309 on September 17, 2016, 02:10:58 pm

Title: RCA Power Amp Fuse
Post by: dpm309 on September 17, 2016, 02:10:58 pm
I have the power amplifier section from an old RCA console that I am trying to restore. On one of the fuses I am not getting any continuity. It is reading 6M ohms and greater so I am assuming it is bad. The fuse is a dog-bone shape made out of a ceramic type material. I have attached a picture of it and the schematic for it and was wondering what would be a good replacement. The schematic does not list values for this. Don't know if this is the proper forum but I am not having any luck on any of the antique radio forums. Has anyone ever seen one of these? Also does anyone know of any other forums I that might be able to help?

Thanks
Title: Re: RCA Power Amp Fuse
Post by: PRR on September 17, 2016, 02:33:45 pm
It's a resistor.

Try 100 Ohms 10 Watts.
Title: Re: RCA Power Amp Fuse
Post by: dpm309 on September 17, 2016, 03:28:52 pm
Thanks, PRR. The schematic shows this component as a fuse: F401 (I hi-lighted it on the schematic - yellow dot). Could this be a thermal fuse/resistor?
Title: Re: RCA Power Amp Fuse
Post by: HotBluePlates on September 17, 2016, 04:06:44 pm
Thanks, PRR. The schematic shows this component as a fuse: F401 (I hi-lighted it on the schematic - yellow dot). ...

No schematic attached or linked.
No model number of the console.
=
No way to know what you're seeing.


EDIT: Overlooked the schematic in the OP.
Title: Re: RCA Power Amp Fuse
Post by: dpm309 on September 17, 2016, 04:55:26 pm
HotPlate,

You should be able to open up the PDF in my initial post. It is a RCA Model VRM 05M with an amplifier chassis - Model N. RS-203C, and Tuner Chassis - Model No. RC-125D. I only have the RS-203 chassis in my possession.

I have reattached the schematic.
Title: Re: RCA Power Amp Fuse
Post by: HotBluePlates on September 17, 2016, 07:13:51 pm
HotPlate,

You should be able to open up the PDF in my initial post. ...

I'm very sorry!  I obviously overlooked that in your original post!
Title: Re: RCA Power Amp Fuse
Post by: PRR on September 17, 2016, 08:40:25 pm
> The schematic shows this component as a fuse: F401

Nevertheless, I would stick in a 50 or 100 Ohm 10 Watt resistor.

The antique diodes need some current limiting.

The darn thing sure LOOKS like a resistor.

50 Ohms here won't do much good or bad, but will burn-up fast if a rectifier fails short.