The Tektronix 504 is a monolithic oscilloscope with a bandwidth of 450 kHz introduced in 1960.
It was introduced at the same time as the 503, and is mechanically and electrically identical, other than the vertical amplifier.
The 504 was also offered in a rack mount version, the RM504.
The 503 incorporates two identical phase matched amplifiers with true differential inputs to support X-Y operation, whereas the 504 contains a simple ground referenced vertical amplifier. Due to the low bandwidth and need to keep the selling price low, neither the 503 or 504 include delay lines in the vertical signal path. Both scopes use the same CRTs, the T5030.
The CRT circuit uses a single 5642 to generate the -3000 V cathode voltage. There is no post-deflection acceleration.
Triggering is done using a multivibrator made of a 6DJ8 tube. The vertical signal path has a 6DJ8 first stage, a BJT second stage, followed by the the output stage. The vertical and horizontal output stages use pairs of 6CB6 tubes.