[Tubester]

Just picked up a Philco 610B a few months back to begin a new hobby of radio restoration. By way of introucition, I'm a retired electrical/mechanical engineer from the auto industry and getting it re-capped brought back memories from my early years working in instrumtation groups. Also have fond memories of checking tubes from the early TV's using some of the tube testers locally where I lived at that time. But I digress! I have completely cleaned and recapped my chassis. I have created an 'actual' schematic which compares very well with the 'later production' schematics out there showing phonograph wiring. I say actual, because there are some differences that don't make sense to me. For example, the 6A7 tube cathode is grounded with the filament ground. The pair of 51 and 25 k ohm resisters are, instead of being connected to the 6A7 cathode, are wired to the 78 tube grid 3, which is also wired into the BC resistor no. 57. Additionally, the oscillator has some descrepences with the later production schematic. The oscillator seems to be wired correctly for the standard and police boradcast bands (positions 1 and 2 on the bandswitch), but position 3 is another story. The secondary side seams to be ok, but the primary side does not seam right. For example, there is a wire which connects the shortwave band primary input into the 6A7 grid 2 anode directly, although there also is also a feed from the switch 1 connection when in position 3 for shortwave. Also, there is a common side to the shortwave primary/secondary's at the 2250 pF and compensating condenser nut 13 shown in the schematic, which is not there in my unit. So my questions relate to these variances from the later procution schematic. Although the radio does power up and I can play stations from band 1 and 3, there is noticable static or hum. Do any of you experienced vacuum tubers have any thoughts? Should I just rearrange a few wires to agree with the oem schematics + documented service bulletins and call it a day? Thanks in advance from Dan the Tubester.