CBS radio
 

I just got a red portable CBS-Columbia model 5110 radio. It needs a 76.5v.battery but I was able to run it with a power supply I made. The performance of this 4 tube set was great. It is picking up better than my 8 tube Zenith console. I did take it apart and the tiny paper caps look crappy. i would like to replace them but I can't find the diagram on nostalgia air.Can anyone give me a Sam's number? I have access to them but I do not have a master index. I figured this little set would be a poor performer being a hand held battery set with just 4 tubes but I am impressed. Am I lucky or were they usually pretty good?

Check this out:

http://techpreservation.dyndns.org/s...a_5110_18.djvu

You'll need a djvu plug in viewer to access schematics on this site.

Thanks, that is what I needed!

If you want to run this on batteries, note that the two A cells are installed in parallel, not in series, so voltage remains at 1-1/2 volts. You can make up a B battery by snapping together cheap 9-volt transistor radio batteries from the dollar store. Snap them together positive of one to negative of the next one and so on in a chain. They will sort of fall together in a block that way. You could use eight of them to get 72 volts which would be fine in lieu of the 67-1/2 volt battery that this calls for. You can buy a nine-volt battery snap from RS and cut it in two to get your two individual snaps to connect to your new battery block. Have fun! :banana:

Thanks, that was kind of my idea too, I just hope there is enough room to put the nine volter's inside the case. I guess I will find out later today, I still can't get over how well this radio works!

I don't think a batch of 9 volts will fit. That battery is a 477.

A string of A23 12-volt batteries will work. It's what I use in my replica packs.

Bill

It has the same complexity as a tabletop AA5:

converter
i.f. amplifier
detector-AVC-a.f. amplifier
power amplifier

so performance can be expected to be similar. Also you may have noted
the instant-on feature of these filament tubes. Good luck.

I don't know if I would like using a stack of A23's for the "A" supply, an A23 is basically a pack of button cells, and life can be severely limited. I used to use four A23s in my Motorola Pixie, and the life was really short (incredibly the 415 "B" battery for the Pixie is still in production!). If it can fit, stacking 9V "transistor" batteries (today, usually used only in smoke detectors) is better.

If the dual "A" batteries are both the old "G size" batteries, and the radio has parallel filament supply, I would strongly urge you to try only one alkaline D battery for the "A" supply.

I have one (an seen other) radios that used two "Size G" for the "A" supply, in an effort to reduce how often one needs to replace the "A" batteries.
This was never good engineering practice. Once one battery got to be weaker with the other, current would start flowing from the stronger battery, backwards through the weaker one. Eventually, one or both batteries burst, leaking acid all over the radio's innards. I have seen portables ruined by this. (BTW, you can make a "Size G" battery by placing a "Size D" at one end of a toilet paper tube, + tip protruding, and placing balls of crumpled foil into the tube under the - end).

I find that battery portables often have good reception because they are not connected to the power grid (and all of the interference from modern gadgets plugged into it) and can be used outdoors for even less interference. I regularly listen to WSM (about 350 miles away) and CFZM (about 250) on my tube portables.

You may be able to find out what kind of capacitors to replace the wax paper caps with by reading the figures often printed in plain numbers on the wax paper caps themselves. Good luck.

Thanks, my set takes two "c" batts. for the a- supply. I did read your thoughts on that and I will keep a good eye on it. stacking nine volt batteries will not work, there just is not room. I can put 6 nine volters in it, thats it. I does work but not as good. I am thinking about getting the batterymaker's 477 and give it a try. maybe I will try to log hours of use and post it here.

[QUOTE=Robert Grant;2969128]I don't know if I would like using a stack of A23's for the "A" supply, an A23 is basically a pack of button cells, and life can be severely limited. I used to use four A23s in my Motorola Pixie, and the life was really short (incredibly the 415 "B" battery for the Pixie is still in production!). If it can fit, stacking 9V "transistor" batteries (today, usually used only in smoke detectors) is better.

I know you mean--but in most cases--a string of 9 volts won't fit. So, it's a compromise.

True!

An especially unattractive kludge was using five 9Vs with my Pixie - I had to run the "B" wires out the back cover to the external pile of five 9V batteries held to the radio by rubber bands!

I'm really curious, what is the difference between the 479 and the 495?

I do not know if clouds or something else is helping, but I have picked up a station in New Jersey and stations like KDKA out of Pittsburgh with this radio in my basement. I can't wait to get a proper fitting battery in this set. The 6 nine volt batteries I squeezed in are rattling around everytime I move the set.

479 is thinner than the 495. 495 and 437 share the same thickness, about an inch and a half or so.

477 and 479 are about an inch thick.