Kenwood FR-4010 and KR-5010 Bias

Wolfdaddy

New Member
Kind of new to this and need some help with these receivers. The 5010 belonged to my uncle. It's been sitting for 20 years I'd guess. My teenage son and I want to get it going to use in our game room. The 4010 we picked up free. My son would like to set it up in his high school longer room along with some speakers that were donated to us.

We're assembling a dim bulb tester right now. We plan to do what seems to be normal in cases like this (assuming we see no problems with the dim bulb): deoxit, recap, bias and offset.

We've hit a wall with the bias. We grabbed the service manual from hifiengine.com. It's that same manual for both units. The adjustment section covers offset, power meters and AM/FM. Nothing about bias.

Am I missing something? I'm guessing they used fixed resistors (not pots) to set the bias at the factory. I'm not good enough to figure that out from the schematics. I've seen posts about changing fixed resisters to pots to be able to adjust the bias, but it wasn't for these two units in particular. I'd be fine with doing that if someone could tell me what to change. I'm also fine with trying different fixed resistors to get the bias set.

Two big questions: what should the bias be and where/how do we measure it?

Thanks in advance for helping!
 
Back
Top Bottom