EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

While I wait for some re-chroming to get finished on my Scott 16, I decided to start on my 16A.

Question: There are a LOT of Tobe and Sangamo molded capacitors in this thing.  What are they, Mica or molded paper?  Do they hold up or should they all be replaced?

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I'll look that up!

Hmmm. Can't seem to find the info on 800B tone modifications.  I looked at the schematic for the 800B and the circuit is considerably different, with the 16A being much more complicated.  The cathode of the 6SL7 that is involved with the treble does have a lot of resistance in the cathode and it is not bypassed. but, I have no problem with hum.  I'm not very good at deciphering some of these circuits so I'm not at all sure what does what in the tone circuit.

Norman, if you read this, can you point me to the modifications for the 800B and do any of them apply to the 16A?

Thanks!

Rob

In the 16A the tone controls are placed between V6 a 6SL7G, the 2nd AF Amp., and V7 a 6J5 Audio Coupling. It does appear that the cathode resistor of the left half of the 6SL7 is a high value, perhaps 10K ohms (I can't quite make out the value on the blurry schematic I have). If that is true that particular stage might be susceptible to hum. Norman will probably know. I have no experience with the 16A.

Joe

Modifications are here...

http://ehscott.ning.com/photo/albums/scott-800b-art-cabinet

But they do not apply for the Metropolitan 16A.  Have you replaced the black dominoe capacitors in the noise suppressor circuit?  They are wax paper.

Norman 

Thanks guys.  Norman, all of the domino caps have been changed and the noise reduction circuit does work...I think.  I can tell that there is some gated treble reduction on one of the settings.  I can't find any info on calibrating the system so I have left the settings alone. since it doesn't seem to improve the sound of the radio, I don't use it.

Changing the de-emphasis caps  as helped considerably in the high frequency response of the radio.  Now very acceptable.  i would like to play with the IF band pass some day.  it seems that the Treble control affects the mid range as much as the high frequencies making the sound of the radio a bit harsh if the treble is turned up too much.

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