Hello folks, in the process of gathering parts for my FM station I ran into a Harris MS-15R stereo encoder at picked it up. After going through it before I fired it up I noticed the stereo analog card has a missing part and resistor R66 is a little burnt up. There shouldn't be a need to explain why I want to use this instead of a cheap single card encoder unit. Anyone have any experience with one of these? Harris is of no help due to the age. I have no schematics and have found no help anywhere.... Thanks so much to anyone that can help!!! If you would like a picture of the card send me a PM and I'll shoot one over to you....
Protect freedom, or freedom won't be there to protect you....
Huh well good find. If you can figure out what the value of that resistor is you should replace it with another one that can handle more heat dissipation, or in other words higher watt rating. I don't know too much about the unit, but I wouldn't put it past others here to know a thing or two about what you got there.
Have you fired it up and does it work alright besides the stereo card missing? Just checking if the power supply in it is okay and such since a burnt resistor can sometimes be a sign of a part it's connected to not working correctly, but it could just be from long term use and age.
I'll get the camera out tomorrow and shoot some picks of the unit and the board that's not working. It seems that the resistor is heating up because of a bad voltage regulator or something of that nature. Due to the fact it is already 5w carbon comp, I don't think I want to replace it with something bigger.
I have been meaning to drawl up a schematic of the card but haven't had a chance yet. I'll post some pics tomorrow so you can check it out and get an idea of the circuit. It is a very neat device, I am almost sure it was one of the first stereo encoder units made by Harris. It will be very cool if I can get it back on the air again!
Protect freedom, or freedom won't be there to protect you....
Ok, sorry for the long delay here. I got real busy with work for a bit... Here are the pictures of the board in question. The resistor that is overheating is directly above R26 at the very bottom left of the first picture. The board as I said has been modified and I'd like to return it to it's original construction if I can. Anyone with any ideas feel free!
Protect freedom, or freedom won't be there to protect you....
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