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 Post subject: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Mon 14, 2021 7:34 pm 
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Location: Riverside Ca. 92504
I have been working on a Emerson CE 259 for a while now and I can not get it to work.
http://www.nostalgiaair.org/Resources/download.asp?FN=\M0004919.pdf... It has been recapped with the dry electrical 8 mfd cap. being replaced with a 10 mfd elect. Cap. Resisters have been checked and most replaced. This radio takes a 1.5 volt A and a 90 volt B battery supply. It is only battery powered. The radio will not turn on. There is a lot of grounds in this unit with all filaments measuring 1.4 volts terminating in ground. When both voltages are applied the 90 Volts drops to 12 volts. The speaker and output transformer can be on or off with the circuit with the same results. If I take off the filament 1.5 volts the B voltage will go up to 78 volts. Put the filament voltage on and it drops again. I have checked for shorts, bad tubes, removed one tube at a time , retested tubes and I am at a loss. This is a very clean radio and I would like to get it running. Tom


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Mon 14, 2021 8:07 pm 
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Your link is corrupted, so I've tried another one:

http://www.nostalgiaair.org/pagesbymode ... 004919.pdf

Are you sure your 90 volt supply is up to the task?
If so, there is one connection going to the wrong pin, or two leads touching.

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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Mon 14, 2021 8:41 pm 
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Joined: Feb Fri 01, 2019 11:35 pm
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Location: Riverside Ca. 92504
I am using two batteries that I normally use for radios. They are regular 45 volt cells. I wired it according to the schematic with the blue ( negative ) 90 volts going to the 1C5 and the red going to the on off switch. The 1.5 volts has negative grounded to chassis and the positive going to on off switch. I could try a different power supply to see if it is the batteries that measure 88 volts ganged together. Tom


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Mon 14, 2021 9:27 pm 
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Location: Lexington, KY USA
I wired it according to the schematic with the blue ( negative ) 90 volts going to the 1C5

The linked schematic shows no 1C5. The linked schematic shows the negative end of the B battery going only to R11, and R10.

Be sure this is corrected before applying power.

Measure the B+ current with the present setup. It may be pretty high, and you don't want more.

It sounds as if one or more control grid is being driven positive. Perhaps connected right to B+.

With the parallel filaments you can unplug tubes to see which stage is drawing the current. With no tubes, connecting the A battery should make no difference.

R11, 680 ohm, can serve as a B+ current shunt once its value is verified.

Ted


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Mon 14, 2021 9:34 pm 
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What are you using for B batteries? New 45 volt batteries are quite expensive. Are you using old batteries? 88 volts with no load sounds a little low. Are your batteries dead?

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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Tue 15, 2021 4:15 am 
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Joined: Feb Fri 01, 2019 11:35 pm
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Location: Riverside Ca. 92504
I brought the 45 volt batteries on a battery site I guess they still use them in some equipment and sell them They are fairly new. I have a power supply hid somewhere and will use that.. It is variable and can generate the correct voltages. Earlier versions called for a 1Q5 but was changed with a production to the 1C5 at a certain serial number. I should not have shortcut it to the connection but the negative 90 volts does got to the R10 and R 11 junction then to the 1C5. R11 is a wire wound and measures 740 ohms. I still can not figure out that the plate voltage goes up to 75 volts and when I apply filament 1.5 it drops to12 volts. I have been looking to see if there are any shorts in the filament line but all measure around 1.4 to ground. all filaments go to ground. I think my next move will be to replace the 680 ohm wire wound but I do not think that would drive the voltage down. I am also thinking of pulling all the new parts and soldering them in. I just got in Zenith R 520A from Germany and it is a mess The chassis was not bolted own and smashed the front plastic plate. It is also water damaged and has been rewired. It will take a lot of glue. Tom


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Tue 15, 2021 8:30 pm 
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Location: Vancouver Island, Canada
Usually Lurking wrote:
I wired it according to the schematic with the blue ( negative ) 90 volts going to the 1C5

The linked schematic shows no 1C5. The linked schematic shows the negative end of the B battery going only to R11, and R10.

Be sure this is corrected before applying power.

Measure the B+ current with the present setup. It may be pretty high, and you don't want more.

It sounds as if one or more control grid is being driven positive. Perhaps connected right to B+.

With the parallel filaments you can unplug tubes to see which stage is drawing the current. With no tubes, connecting the A battery should make no difference.

R11, 680 ohm, can serve as a B+ current shunt once its value is verified.

Ted
Read this again, you can remove a tube to see if there is a change in B+.
Don't take any shortcuts with the B- connection. It goes to a voltage divider made up of those 2 resistors, sounds like.

_________________
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Burl Ives, RIP, oldtimer.
[:l>)


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Wed 16, 2021 4:21 am 
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Joined: Feb Fri 01, 2019 11:35 pm
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Location: Riverside Ca. 92504
I am dealing with a illness in my family .. I will make checks Thursday Tom


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Wed 16, 2021 6:29 am 
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tomb123 wrote:
I am using two batteries that I normally use for radios. They are regular 45 volt cells. I wired it according to the schematic with the blue ( negative ) 90 volts going to the 1C5 and the red going to the on off switch. The 1.5 volts has negative grounded to chassis and the positive going to on off switch. I could try a different power supply to see if it is the batteries that measure 88 volts ganged together. Tom

You can wire 10 nine volt Transistor batteries in series for the 90 volts. Plate circuits don't require much current. I've done that with several battery farm sets.

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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Wed 16, 2021 11:42 pm 
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Location: Tucson, Arizona U.S.A.
tomb123 wrote:
I am also thinking of pulling all the new parts and soldering them in.

So how are they connected now? Unsoldered connections and parts hanging loose are an invitation to trouble. Worse is if they are all connected with clip leads. Definitely install them properly.

R11 is the back bias resistor for the output tube, just like in AC operated sets.

It wasn't clear (to me at least) if you pulled the tubes one at a time or all at once. Pull them all at the same time and see what your B+ voltage is. If it still is no good, you have a short in the wiring, a miswire, or a bad component. If it is OK with no tubes, put them back in one at a time leaving all the others out. If you find one that causes a severe voltage drop, you are closer to the problem.

Measure the B+ current with all the tubes in. If it is more than 10 mA or so, you have a circuit problem. If it is less than this, your batteries are dead.

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Jim Mueller

Who's that swimming in the punch bowl?
It's Walter Wart, the freaky frog!


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 Post subject: Re: Need help on repairing a 1938 Emerson CE-259
PostPosted: Jun Sat 26, 2021 11:17 pm 
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Joined: Feb Fri 01, 2019 11:35 pm
Posts: 673
Location: Riverside Ca. 92504
fifties wrote:
tomb123 wrote:
I am using two batteries that I normally use for radios. They are regular 45 volt cells. I wired it according to the schematic with the blue ( negative ) 90 volts going to the 1C5 and the red going to the on off switch. The 1.5 volts has negative grounded to chassis and the positive going to on off switch. I could try a different power supply to see if it is the batteries that measure 88 volts ganged together. Tom

You can wire 10 nine volt Transistor batteries in series for the 90 volts. Plate circuits don't require much current. I've done that with several battery farm sets.



Had bad news from my family. I worked on it yesterday and today. Changed tube out rechecked all solder points, rechecked the wiring to no avail I was using some 45 volt batteries that have worked on other radios. Finally found my power supply put it on and it works well. Next will to stuff some period batteries to go in it Tom


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