Resistance check question [resolved]

[ArtnShit]

Hello,

Apologies for the flurry of build Q's!

I am on page 52 of the build manual performing resistance checks. It says it should read "very close" to 445ohms. Both A4 and A1 read at 442ohms. Is this close enough?

Thanks in advance!
a&s

[Paul Birkeland]

Oh yeah, that's great!  What we are after there is to be sure all the resistors are put in the proper places before allowing the 300B to potentially find out for you.  442 is 0.7% off, so plenty close!

[ArtnShit]

Ok cool!! Thanks Paul.

For future reference what percentage of error is usually acceptable for resistance deviation?

[Paul Birkeland]

Resistors are generally 1% parts these days though wirewounds and some other random ones we use are more like 5% (the big 3K 10W resistors in your kit probably don't measure exactly 3K as an example).  Meters are also somewhat imperfect, but if you're within 5% that should be OK.

There's certainly no need to apologize for asking questions, that's definitely a safer bet than making assumptions.

[ArtnShit]

One last quick voltage check question - terminals 6 and 16 are measuring at 99vDC and 98vDC, respectively. Is that ok to have different results from both sides? So far any deviations from the manual benchmarks have been parallel on both sides of the amplifier.

[Paul Birkeland]

Yes, that's totally OK. You can see the meter measurements in the photos in the manual show 99V and 98V for the one we built for the photos.