#1
|
||||
|
||||
1955 Motorola 17T20
I got this set for free, just had to drive 75 miles both ways to get it but for free why not. I got this set home and powered it up, the tubes light up but no HV or sound, i knew then this set had no B+ so i pulled the chassis and found many a problem like falling apart sand resistors, fried and cracked resistors, split bumblebees and i think the selenium is bad but not sure at this moment. All the caps and some resistors will need to be replaced obviously. I haven’t checked the tubes yet because my tester went out and I don’t have a spare, but luckily a stereo store near me lets you test tubes for free and there is an upcoming hamfest i’m going so i can hopefully get a new tester.
__________________
Your good times will bring me down |
#2
|
||||
|
||||
Not in bad shape
__________________
Your good times will bring me down Last edited by Celt; 05-16-2018 at 10:37 AM. |
#3
|
||||
|
||||
Don't bother testing the selenium, just replace it with a 1n4007.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#4
|
||||
|
||||
Agreed...I do that on all old tweed Fender amps.
__________________
Let me live in the house beside the road and be a friend to man. |
#5
|
|||
|
|||
Quote:
No B+, check the plug in resistor on top of the chassis, usually a 7.5 ohm, 5 watt. Make sure the speaker is plugged in, as the field coil is the B+ choke. |
Audiokarma |
#6
|
||||
|
||||
Thats what i’m going to do.
__________________
Your good times will bring me down |
#7
|
|||
|
|||
I always do a preliminary assessment of the condition of the set, by just replacing the obvious defective parts and checking the CRT.
A schematic is generally needed and makes it easier. I don't do wholesale changing of parts until I know what's involved. I still do it in stages. Motorola made about three years of this chassis. They were always easy to get going, but that was when they were less than 10 years old. |
#8
|
||||
|
||||
This looks like the American cousin of the Marconi I'm working on right now, 17" series string set, with a half wave selenium rectifier? What picture tube does this one use? Look forward to following this project.
|
#9
|
|||
|
|||
Quote:
Yours is very similar to the US designs. |
#10
|
||||
|
||||
Quote:
|
Audiokarma |
#11
|
||||
|
||||
Quote:
__________________
Your good times will bring me down |
#12
|
||||
|
||||
This set was made August 1954
__________________
Your good times will bring me down |
#13
|
||||
|
||||
Top and bottom view of the chassis
__________________
Your good times will bring me down |
#14
|
||||
|
||||
Looks really nice, I look forward to seeing how it works!
|
#15
|
||||
|
||||
I parted out a similar vintage moto monochrome with a weak CRT and a ruined cabinet...I still have most of the chassis and may be able to supply parts if needed.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
Audiokarma |
|
|