There are 77 chrome plated brass rivets in the tuner-chassis of a Scott 16, plus or minus 1 or 2, since they are not all the same. This includes the shield cans (not pictured) but does not include the audio amp chassis, which has many more.
In some cases the individual rivet must capture 5 separate items such as tube shield, tube socket, ground lug, lock washer and solid washer. On top of this assembly there is a braded ground strap which must be soldered on leading to the tuning cap ground.
Other than the shear number of fasteners, why is this impressive? Well, take out a piece of sheet of metal, drill 1 hole in it and try to punch down a rivet with 5 items - some below the sheet - not visible from the top. OH! It also must be a good ground (tight). Then do it 77 times without scratching the chrome or breaking parts. Just fold the metal into a box,, drill 76 more holes in all sides an fill it with a bucket of parts that must be specifically attached to a particular rivet AND the parts must be 80 years old - you'll see.
There are also a couple of dozen screws and nut/bolts but these are of little consequence except for having to bolt/unbolt major components over and over to add riveted components around them. Leaving the large components flopping around is a bad idea.
In some cases the individual rivet must capture 5 separate items such as tube shield, tube socket, ground lug, lock washer and solid washer. On top of this assembly there is a braded ground strap which must be soldered on leading to the tuning cap ground.
Other than the shear number of fasteners, why is this impressive? Well, take out a piece of sheet of metal, drill 1 hole in it and try to punch down a rivet with 5 items - some below the sheet - not visible from the top. OH! It also must be a good ground (tight). Then do it 77 times without scratching the chrome or breaking parts. Just fold the metal into a box,, drill 76 more holes in all sides an fill it with a bucket of parts that must be specifically attached to a particular rivet AND the parts must be 80 years old - you'll see.
There are also a couple of dozen screws and nut/bolts but these are of little consequence except for having to bolt/unbolt major components over and over to add riveted components around them. Leaving the large components flopping around is a bad idea.
The tuning cap is covered by a chromed shield that also has a lead blanket riveted inside. Just saying, but, I think this was a bit much. Rest assured though, the blanket was reinstalled as it was from the factory.
In the following pictures all of the paper caps have been rebuilt. All of the original carbon resistors were within 10% with the exception of 2 that showed signs of heating, probably caused buy a related component (cap) failure. These 2 resistors were replaced with exact factory units from a donor chassis.
The cabinet, refinished but not yet buffed and the audio amp chassis are patiently waiting.
I still need to align the receiver and reinstall the shields or install the shields and align the chassis by pulling the shields one at a time, which will be complicated by the grid leads coming through some of the shields. This radio has a few trimmers that were obviously not intended for field alignment since no access was provisioned.
I still need to align the receiver and reinstall the shields or install the shields and align the chassis by pulling the shields one at a time, which will be complicated by the grid leads coming through some of the shields. This radio has a few trimmers that were obviously not intended for field alignment since no access was provisioned.
Audio amp "before".
Shown with a chassis in typical unrestored state.
More to come.
I still have to figure out how to display this radio so that the "innards" can be seen. Otherwise all of that shine will go unappreciated.
12/10/2015
Spent last night aligning the IF. The slug in the "IF diode coil" drug the coil around - bad for the contact wires. After it was fixed and set to max gain I have too much audio and the eye tube is closed almost everywhere on the band even at its minimum setting (the eye tube has a cal pot). On a short antenna it would be fine, but I am not inclined to settle for that. Going to recheck the values on the AVC, AGC and tapped vol pot today rather than detune, though reducing the gain in this stage probably does not affect sensitivity but does affect the indicator (eye tube) and the IF AGC. If I can get that stage to respond better, that would be the best result.
I still have to figure out how to display this radio so that the "innards" can be seen. Otherwise all of that shine will go unappreciated.
12/10/2015
Spent last night aligning the IF. The slug in the "IF diode coil" drug the coil around - bad for the contact wires. After it was fixed and set to max gain I have too much audio and the eye tube is closed almost everywhere on the band even at its minimum setting (the eye tube has a cal pot). On a short antenna it would be fine, but I am not inclined to settle for that. Going to recheck the values on the AVC, AGC and tapped vol pot today rather than detune, though reducing the gain in this stage probably does not affect sensitivity but does affect the indicator (eye tube) and the IF AGC. If I can get that stage to respond better, that would be the best result.
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