With the help of so many contributors on this thread making it possible, I thought I'd show some photos of the restoration and modifications so far. I bought this 500B off Craigslist. My first Fisher. I heard it operate at the sellers house. Then home to the garage it went, hasn't been inside the house yet.
It is just about up to standards for the living room! Face plate needs to be reinstalled still.
The pictures will be in somewhat random order, as I take them.
Jef
All can caps were restuffed.
It's got some EH 7591's I bought 10 years ago and never used. NOS tubes ?
My power tube adjustment panel. IBAM has been installed. Some nice quality trimmer pots.
EFB board minus the EFB power supply. The power supply is mounted separately on a solder terminal to keep the board small. The 4 resistors in a row are the 15K's for IBAM. This board is mounted "upsidedown" in the chassis for mounting convenience.
Unity buffer op-amp board. Also, the power supply for it is separate to facilitate a small board that can be tucked in along side the volume control, which keeps the wiring short as desired. I also implemented the Preamp Out/Amp In mod where the SpaceExpander jacks were. I also bypassed and de-terminated the remote control jack on the rear of the unit. I saw no use for it and thought it could become a problem if the plug/socket got loose etc. That supplied the shielded cable for the Preamp Out/Amp In mod.
Here we see the EFB board mounted and all the standard other stuff. 1/4w 10 ohm Dale cathode resistors.
100ohm screen resistors. The famous Russian PIO's .068uF 400v to go with the new 220K's. I moved the 1.2K 7w resistor from the power tube area to the power supply section, just seemed where it belonged. The 4 small blue caps are part of IBAM, but mounted off board, again to keep the board small. The two light blue 390K 2 watt resistors were installed as part of the Phase Inverter Noose Removal mod. They feed the lower B+ to the AF stage required by noose removal. I don't care for flying resistor leads so that's why they're added. 2 watt cause I had some.
All electrolytic caps replaced.
All brown turd caps replaced
AC power safety cap replaced and PT secondary cap replaced
Selenium bridge replaced.
The 2 main rectifier diodes replaced
B+ voltages are close to schematic, slightly high
Filament voltages within 5%
LED lamps installed for dial glass
IBAM, EFB and Unity Buffer installed
Phase Inverter Noose removed
Next: Phono PEC replacement and ???
If anyone has suggestions please let me hear.
Thanks... jef
It is just about up to standards for the living room! Face plate needs to be reinstalled still.
The pictures will be in somewhat random order, as I take them.
Jef
All can caps were restuffed.
It's got some EH 7591's I bought 10 years ago and never used. NOS tubes ?
My power tube adjustment panel. IBAM has been installed. Some nice quality trimmer pots.
EFB board minus the EFB power supply. The power supply is mounted separately on a solder terminal to keep the board small. The 4 resistors in a row are the 15K's for IBAM. This board is mounted "upsidedown" in the chassis for mounting convenience.
Unity buffer op-amp board. Also, the power supply for it is separate to facilitate a small board that can be tucked in along side the volume control, which keeps the wiring short as desired. I also implemented the Preamp Out/Amp In mod where the SpaceExpander jacks were. I also bypassed and de-terminated the remote control jack on the rear of the unit. I saw no use for it and thought it could become a problem if the plug/socket got loose etc. That supplied the shielded cable for the Preamp Out/Amp In mod.
Here we see the EFB board mounted and all the standard other stuff. 1/4w 10 ohm Dale cathode resistors.
100ohm screen resistors. The famous Russian PIO's .068uF 400v to go with the new 220K's. I moved the 1.2K 7w resistor from the power tube area to the power supply section, just seemed where it belonged. The 4 small blue caps are part of IBAM, but mounted off board, again to keep the board small. The two light blue 390K 2 watt resistors were installed as part of the Phase Inverter Noose Removal mod. They feed the lower B+ to the AF stage required by noose removal. I don't care for flying resistor leads so that's why they're added. 2 watt cause I had some.
All electrolytic caps replaced.
All brown turd caps replaced
AC power safety cap replaced and PT secondary cap replaced
Selenium bridge replaced.
The 2 main rectifier diodes replaced
B+ voltages are close to schematic, slightly high
Filament voltages within 5%
LED lamps installed for dial glass
IBAM, EFB and Unity Buffer installed
Phase Inverter Noose removed
Next: Phono PEC replacement and ???
If anyone has suggestions please let me hear.
Thanks... jef