I think round tubes mostly gave way to square by the 60s.
I think round tubes mostly gave way to square by the 60s.
The RCA 151 oscilloscope was a cost-reduced scope made in 1936. While still expensive, this scope brought visual trace confirmation in the price range of the experimenter and small radio shop. This cost $47.50 in 1936, which is roughly $960 today.
This unit was built in Montreal, Canada, and was designed to operate on 25Hz power. This simply means it had a bigger filter in the power supply to compensate for the ripple from the lower frequency. It operates fine on modern US 60Hz power.
Tube lineup is a type 80 for the rectifier, a type 885 for the sweep, and two 6C6 that handle the remaining functions. The CRT is a 1" 913 tube. The 80 and 6C6 are fairly common today, the others are scarce or unobtainable.
This particular example is fairly pristine save for the "oops, it was live" mark on the right side near the input jacks. The inside appears to have been worked on at some point in the distant past, probably before WWII. I didn't open it because I need to clear another project off my actual test bench before doing so, but there are plenty of examples of the inner works online.
Here's the original ad for the scope (not mine) http://www.myvintagetv.com/oscilloscopes/rca_151_adv.jpg The inside (again, not mine) http://www.myvintagetv.com/oscilloscopes/rca_151_inside.JPG
The RCA 151 oscilloscope was a cost-reduced scope made in 1936. While still expensive, this scope brought visual trace confirmation in the price range of the experimenter and small radio shop. This cost $47.50 in 1936, which is roughly $960 today.
This unit was built in Montreal, Canada, and was designed to operate on 25Hz power. This simply means it had a bigger filter in the power supply to compensate for the ripple from the lower frequency. It operates fine on modern US 60Hz power.
Tube lineup is a type 80 for the rectifier, a type 885 for the sweep, and two 6C6 that handle the remaining functions. The CRT is a 1" 913 tube. The 80 and 6C6 are fairly common today, the others are scarce or unobtainable.
This particular example is fairly pristine save for the "oops, it was live" mark on the right side near the input jacks. The inside appears to have been worked on at some point in the distant past, probably before WWII. I didn't open it because I need to clear another project off my actual test bench before doing so, but there are plenty of examples of the inner works online.
Here's the original ad for the scope (not mine) http://www.myvintagetv.com/oscilloscopes/rca_151_adv.jpg
The inside (again, not mine) http://www.myvintagetv.com/oscilloscopes/rca_151_inside.JPG
(post is archived)