08-10-2026, 08:32 AM
Only for watching and a help with alignment. Others that have a converter will give better advice.
There was still 405 line TV when I last was repairing 405 sets!
The #1 item is probably capacitors. Likely a 1959 design and made late 1959 or in 1960, so may use paper dielectric capacitors. Not all have a waxed cardboard case. Some are "Modseal" which is now crumbling black or dark reddish material. Some are metal cans with rubber bungs at each end. Generally 470 pF to 1 uF. All need replaced.
Mica, ceramic or plastic delectric caps will be fine.
Any Electrolytics may reform (use a 30V PSU and 10mA current limit, 50mA max). The current should drop to less than 1mA after 4 to 10 hours if OK. If there is no current (or a lot of hum eventually), then an electrolytic may be dried out.
Ensure it's in a warm dry place for days in case the LOPT (EHT transformer) is damp.
Only replace valves with an open circuit heater, to start with.
Don't power up without checking main rectifier and replacing the paper dielectric caps.
Almost all the repair & restoration is possible with no signal. A full screen of noise/snow and hiss on audio. Not worth spending money on a converter if you don't get that far.
Some PC graphics cards and some Raspberry Pi models can do 405 line, but that is only baseband video and you'd still need a pair of modulators for video and sound. An AM signal generator (60 MHz band) can help fault find if the video or audio is dead after doing all the normal stuff. The Line drive is only 10.125 kHz so you might hear it.
The mains or line drive boor (about 800V?) or EHT can be fatal.
There was still 405 line TV when I last was repairing 405 sets!
The #1 item is probably capacitors. Likely a 1959 design and made late 1959 or in 1960, so may use paper dielectric capacitors. Not all have a waxed cardboard case. Some are "Modseal" which is now crumbling black or dark reddish material. Some are metal cans with rubber bungs at each end. Generally 470 pF to 1 uF. All need replaced.
Mica, ceramic or plastic delectric caps will be fine.
Any Electrolytics may reform (use a 30V PSU and 10mA current limit, 50mA max). The current should drop to less than 1mA after 4 to 10 hours if OK. If there is no current (or a lot of hum eventually), then an electrolytic may be dried out.
Ensure it's in a warm dry place for days in case the LOPT (EHT transformer) is damp.
Only replace valves with an open circuit heater, to start with.
Don't power up without checking main rectifier and replacing the paper dielectric caps.
Almost all the repair & restoration is possible with no signal. A full screen of noise/snow and hiss on audio. Not worth spending money on a converter if you don't get that far.
Some PC graphics cards and some Raspberry Pi models can do 405 line, but that is only baseband video and you'd still need a pair of modulators for video and sound. An AM signal generator (60 MHz band) can help fault find if the video or audio is dead after doing all the normal stuff. The Line drive is only 10.125 kHz so you might hear it.
The mains or line drive boor (about 800V?) or EHT can be fatal.
