04-03-2009, 12:12 AM
Hi everybody, thanks for activating my membership Ron !
well, I finally took the plunge and decided to repair a tube radio for the first time
I don't quite understand how the number coding works on these units so I'll show you what I got ... the inside label says 650 and from what I can tell this unit was made in Toronto around 1938, and is of the super heterodyne style - in the lower LHS of the paper sticker appears 39-4208 - does this mean anything ?? useful for tuning guides or something ?
[Image: http://www.lynx.net/~jc/Philco650.jpg]
[Image: http://www.lynx.net/~jc/Philco650label.jpg]
[Image: http://www.lynx.net/~jc/Philco650dataplate.jpg]
when I got the radio it worked at first, I did get some audio and I could tune into stations albeit with relatively poor reception - of course with no antenna connected to the hookups on the back side of the chassis ...
I took the tubes out to clean them, applied compressed air to get dust and stuff out of the chassis and tuning fans - had a quick look around ... I re-inserted the tubes in and got no reception, the third time I fired it up I got some smoke ...
the first thing I'm going to do is change the electrolytics - I have no way of testing the tubes so I'll assume they're ok for now ... I noticed some of the electro's in the schematic lie around 8uF/450 and I'm wondering if there's any risk going to 22uF/450 instead of 8uF or 10uF ?? will this send the tuning range way off or something ?
I checked the bias on the power tubes and measured -35v to chassis on the coil resistor.
I'm assuming I'm measuring the right voltage ... see pic below:
[Image: http://www.lynx.net/~jc/Philco650chassis.jpg]
[Image: http://www.lynx.net/~jc/Philco650schemCrop.jpg]
Also, the speaker chord appears to be intermittent at the connector end ...
any advice for rewiring that part ??
[Image: http://www.lynx.net/~jc/Philco650spkr.jpg]
I've downloaded a bunch of tuning directives and getting ready for that eventually ...
thx for any help
~jc
---
well, I finally took the plunge and decided to repair a tube radio for the first time
I don't quite understand how the number coding works on these units so I'll show you what I got ... the inside label says 650 and from what I can tell this unit was made in Toronto around 1938, and is of the super heterodyne style - in the lower LHS of the paper sticker appears 39-4208 - does this mean anything ?? useful for tuning guides or something ?
[Image: http://www.lynx.net/~jc/Philco650.jpg]
[Image: http://www.lynx.net/~jc/Philco650label.jpg]
[Image: http://www.lynx.net/~jc/Philco650dataplate.jpg]
when I got the radio it worked at first, I did get some audio and I could tune into stations albeit with relatively poor reception - of course with no antenna connected to the hookups on the back side of the chassis ...
I took the tubes out to clean them, applied compressed air to get dust and stuff out of the chassis and tuning fans - had a quick look around ... I re-inserted the tubes in and got no reception, the third time I fired it up I got some smoke ...
the first thing I'm going to do is change the electrolytics - I have no way of testing the tubes so I'll assume they're ok for now ... I noticed some of the electro's in the schematic lie around 8uF/450 and I'm wondering if there's any risk going to 22uF/450 instead of 8uF or 10uF ?? will this send the tuning range way off or something ?
I checked the bias on the power tubes and measured -35v to chassis on the coil resistor.
I'm assuming I'm measuring the right voltage ... see pic below:
[Image: http://www.lynx.net/~jc/Philco650chassis.jpg]
[Image: http://www.lynx.net/~jc/Philco650schemCrop.jpg]
Also, the speaker chord appears to be intermittent at the connector end ...
any advice for rewiring that part ??
[Image: http://www.lynx.net/~jc/Philco650spkr.jpg]
I've downloaded a bunch of tuning directives and getting ready for that eventually ...
thx for any help
~jc
---
