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1937 Coronado Model 650 Farm Radio
#16

You could build a power supply. For the B voltage a small 12 volt lead gel cell and a pure sine wave power inverter 100 watts and the design listed above on Phils site. The A voltage same 12 volt battery and one of these your choice.   https://www.alldatasheet.com/datasheet-p...LM138.html    or https://www.alldatasheet.com/datasheet-p...M338T.html   or https://www.alldatasheet.com/datasheet-p...LM350.html     Have fun. David
#17

I figured that was too much. But I would definitely like to look into trying to run it off of high capacity rechargeable batteries of NiMH composition or Lithium Ion possibly, I wouldn't be using the radio but for maybe 2 or 3 hours at the most.
#18

Couple of options first a 12volt battery. https://www.amazon.com/Miady-Phosphate-R...282&sr=1-9    The second if money is no object.  https://www.amazon.com/Jackery-Portable-...V5A9DKT3PS   Have the jackery 240 nice piece of equipment great for car camping. I can power my radios at the house without having to run the generator during a power outage..
#19

Quote:Couple of options first a 12volt battery. https://www.amazon.com/Miady-Phosphate-R...282&sr=1-9    The second if money is no object.  https://www.amazon.com/Jackery-Portable-...V5A9DKT3PS   Have the jackery 240 nice piece of equipment great for car camping. I can power my radios at the house without having to run the generator during a power outage..


Hi David, I do have one of those portable 5 and 12 volt power supplies, but its strictly for 5V USB Charging and 12v Cigar Lighter charging, as its also a jump starter for your car and an air compressor for your car as well.

Also I figured out who made this radio, it was Arvin Industries of Columbus, Indiana (Noblitt-Sparks), and it was a rebadge of their "Phantom" series Farm Radios Model Numbers 618B, 628, and 638, with various letter designations after the model numbers to designate whether its a Table Model or a floor model.
#20

That's one of the Electro brand battery eliminators, there are two basic models, one has a 1.5 volt "A" supply, the other a 2 volt "A" supply, you adjust for filament load by shorting out sections of a wire wound resistor through those screw terminals, the one that looks like an antenna/ground terminal. I can't remember but the 2 volt versions may have had a tap for 135 volts, I've only seen that model in ads so I can't say for sure. I have two of the type designed to power radios with the 1.5 volt tubes, supposedly marketed for operating portable radios, according to to the labels, likely because the "B" supply is connected directly to the power line with no isolation, so naturally a ground connection is a no-no. The one radiotvphonunt has is a Sears "PowrShftr" the design is a little different from the Electros in that it has a iron filter choke in the "B+" line, the Electro uses a RC filter with a resistor, so a little cruder, the Sears one may have also had a proper transformer for the "B" supply . 
 No I would not pay $65 for one, and did not for the two I own, the plugs are a nice feature but not essential, many 1930s farm sets had no battery plugs, the batteries had Fahnestock style clips on top for connection purposes. I think that the plug, and socket idea was for the convenience of the uninitiated so they couldn't hook the set up the wrong way, and also to avoid coming into contact with the "B+" voltage. I believe that the hardware stores, or radio shops, must have sold aftermarket battery plugs for the earlier farm sets, I have found several that had built in Fahnestock clips to connect the battery leads to, minus the solder.
Regards
Arran
#21

Quote:That's one of the Electro brand battery eliminators, there are two basic models, one has a 1.5 volt "A" supply, the other a 2 volt "A" supply, you adjust for filament load by shorting out sections of a wire wound resistor through those screw terminals, the one that looks like an antenna/ground terminal. I can't remember but the 2 volt versions may have had a tap for 135 volts, I've only seen that model in ads so I can't say for sure. I have two of the type designed to power radios with the 1.5 volt tubes, supposedly marketed for operating portable radios, according to to the labels, likely because the "B" supply is connected directly to the power line with no isolation, so naturally a ground connection is a no-no. The one radiotvphonunt has is a Sears "PowrShftr" the design is a little different from the Electros in that it has a iron filter choke in the "B+" line, the Electro uses a RC filter with a resistor, so a little cruder, the Sears one may have also had a proper transformer for the "B" supply . 
 No I would not pay $65 for one, and did not for the two I own, the plugs are a nice feature but not essential, many 1930s farm sets had no battery plugs, the batteries had Fahnestock style clips on top for connection purposes. I think that the plug, and socket idea was for the convenience of the uninitiated so they couldn't hook the set up the wrong way, and also to avoid coming into contact with the "B+" voltage. I believe that the hardware stores, or radio shops, must have sold aftermarket battery plugs for the earlier farm sets, I have found several that had built in Fahnestock clips to connect the battery leads to, minus the solder.
Regards
Arran


Hi Arran, It seems that those old battery eliminators aren't very common (at least not as common as what radiotvphononut seems to think they are), as I looked up the Silvertone Powr Shiftr units on ebay and there were only 3 listed on ebay and all 3 of them the sellers wanted $65 for them. I'm not very good at trying to build circuits from scratch, I'm much better at working on stuff that's already built, plus I don't have anyway to make my own circuit boards (printing and etching).

I think I might be better off trying to build a power supply using a 2 D-cell battery clip and and 10 9 Volt batteries daisychained together.
#22

IF interested, the PS circuit used in most non-DC radios of the 1930s/40s can be copied for use in your project - A power trans, 2 electrolytic filters, and a couple of chokes. You would be better off using sand for the rectifier (solid state).

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#23

Well I rigged up a temporary battery supply for this radio and the radio works...sort of.

I can get it to receive the 456 KC IF Frequency, but it comes in across the whole dial and not just around 550 KC where it should be, I also adjusted the IF cans and those were actually peaked out properly where they were supposed to be surprisingly enough, but the radio won't pick up any radio signals through the antenna leads, not even from my signal generator, which is weird because I had tested my Antenna Coil and it tested just fine inspite of having had a power cord wired up to it (the capacitor that went between the antenna coil and the antenna terminal I think was what saved the coil). 

I also attempted to adjust the antenna and oscilator adjustments on the Tuning Cap to no avail.

Any ideas as to what might be going on?
#24

I looked up the Electro brand battery eliminators, apparently the ones I have are the model "P" which has a 5Y3 tube in it, and the model "S" which dispensed with the tube and used a selenium rectifier. I got the first one in a lot of test equipment I was offered years ago, the second I got at a car swap meet maybe four or five years back. Anyhow the one you need to look for is the Electro model "F", as that has the twp volt filament supply, point in fact you could probably convert one of the 1.4 volt units to putting out 2 volts by replacing the copper oxide rectifier with silicon diodes, thanks to less forward drop, but that's an engineering job.
 As to why your radio is not working it could be that the local oscillator isn't running, which is probably due to defective capacitors, but could also be because of a faulty mixer-oscillator tube, I think a 1C6 in this case, or a bad grid cap solder joint, or the grid cap lead.
Regards
Arran
#25

OK So I figured out that I think my Oscillator and Antenna Coils are both fried unfortunately.

I've been testing the Antenna Coil and the Oscillator Coil and they both get O. L. readings on them on both the Primary and Secondary leads.

I guess the coils reference back to Meisner Replacement parts.
#26

I had a Coranado would not Oscillate.......feel the pain.

Paul

Tubetalk1
#27

Yeah. This one I think unfortunately got fried from having an AC power cord wired up to the Antenna coil.
#28

UPDATE: Actually it was just the Oscillator coil that was bad, the Antenna coil was still good. 

The Oscillator Coil looks to of been chewed on by a mouse and the oscillator coil had 3 of its 4 coil wire leads broken loose from the coils.
#29

UPDATE: My oscillator coil came in the mail today and I got it installed and powered on the radio and it works!

I'll need to touch up the alignment a little bit as it is a little distorted sounding when its tuned into a station, but other than that its receiving a ton of stations and it gets really loud too!

See video below to see the radio in action. 

[Video: https://youtu.be/8CO-H8qR_NU]
#30

It sure pulls in the stations Icon_thumbup

Did you find an original coil or use a replacement? Also, what did you finally use to power it up; batteries, power supply or???

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"




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