1939 Silvertone FARM RADIO! AHHH!!

[Tubejunke]

After over 30 years of messing with old radios and avoiding farm radios, one finally landed in my living room via the girlfriend's latest thrift store raid. It's a 1939 Silvertone clearly marked model 6050 6051 which if you use to look up info. or pictures on the WWW will show you data on a 1946 model that is much better looking and plugs into the wall. Silvertone had a really crazy way of cataloging their models. For instance, this is really a Silvertone Order= 57K 6050 Ch= 101.503-1. Go figure!

So, I now have a girlfriend gift that requires separate 4.5 and 67.5 VDC power to operate. Now if someone were really into playing with what amounts to a number of ways of approaching designing the circuits to provide this power, this would be an excellent project. And frankly I'm hoping that person is here reading this as I would like to see it find a BETTER home! LOL!

If it were more of an eye catcher, I may take the leap into these old things, but if you can see much in the little picture I attached you may agree that it is sort of a misshapen design. It is in really nice shape; I must give it that much credit. The dial has a pretty badly worn spot on one side where I guess all of the local stations of the time in whatever area were at.

Of all the ideas for powering these things I have seen, the best seems to be making an AC based permanent supply as opposed to bundling store bought batteries to achieve the voltages needed. Again, it needs a BETTER home owned by someone who enjoys these things and has a battery eliminator. For me none of the options are really cost effective to power an AM radio.

Does anyone here collect farm radios? I guess it fits in with the old breadboard crowd, but the old 20s stuff at least bears the uniqueness of obvious antiquity. Any thoughts?

[dieseljeep]

Originally Posted by Tubejunke

After over 30 years of messing with old radios and avoiding farm radios, one finally landed in my living room via the girlfriend's latest thrift store raid. It's a 1939 Silvertone clearly marked model 6050 6051 which if you use to look up info. or pictures on the WWW will show you data on a 1946 model that is much better looking and plugs into the wall. Silvertone had a really crazy way of cataloging their models. For instance, this is really a Silvertone Order= 57K 6050 Ch= 101.503-1. Go figure!

So, I now have a girlfriend gift that requires separate 4.5 and 67.5 VDC power to operate. Now if someone were really into playing with what amounts to a number of ways of approaching designing the circuits to provide this power, this would be an excellent project. And frankly I'm hoping that person is here reading this as I would like to see it find a BETTER home! LOL!

If it were more of an eye catcher, I may take the leap into these old things, but if you can see much in the little picture I attached you may agree that it is sort of a misshapen design. It is in really nice shape; I must give it that much credit. The dial has a pretty badly worn spot on one side where I guess all of the local stations of the time in whatever area were at.

Of all the ideas for powering these things I have seen, the best seems to be making an AC based permanent supply as opposed to bundling store bought batteries to achieve the voltages needed. Again, it needs a BETTER home owned by someone who enjoys these things and has a battery eliminator. For me none of the options are really cost effective to power an AM radio.

Does anyone here collect farm radios? I guess it fits in with the old breadboard crowd, but the old 20s stuff at least bears the uniqueness of obvious antiquity. Any thoughts?

I looked the schematic in N/A. It shows seven pages, but only one pertains to the set in question. Sears was great for using the same model numbers.
Your set is a Colonial built model. It uses the odd-ball two volt octal tubes, in a series-parallel filament arrangement from 4.5 volt battery. The B+ supply is only 67.5 volts, so the output stage is rather weak.
The cabinets were rather large to house the radio chassis and the batteries.

[wa2ise]

Originally Posted by Tubejunke

So, I now have a girlfriend gift that requires separate 4.5 and 67.5 VDC power to operate. Now if someone were really into playing with what amounts to a number of ways of approaching designing the circuits to provide this power, this would be an excellent project. And frankly I'm hoping that person is here reading this as I would like to see it find a BETTER home! LOL!


Of all the ideas for powering these things I have seen, the best seems to be making an AC based permanent supply as opposed to bundling store bought batteries to achieve the voltages needed.

Well, depending on how interested you are in the girlfriend, I'd build the AC powered power supply. And replace all the wax caps in the radio, and any electrolytics too.

[jr_tech]

Originally Posted by dieseljeep

Your set is a Colonial built model. It uses the odd-ball two volt octal tubes

I don't believe that I have ever encountered 2 volt octals... could you list some numbers?

jr

[dieseljeep]

Originally Posted by jr_tech

I don't believe that I have ever encountered 2 volt octals... could you list some numbers?

jr

Here goes, from the schematic.
1C7G, osc mixer, 1D5GP, IF amp, 1F7G or 1F7GH or 1F7GV, det, 1st AF, 1G5G, audio output. There's other tubes, of this series. Seems like Zenith and Philco used them as well. Sylvania sourced.
IIRC, in my odd tube collection, I have some of this type, Philco branded.
BTW, the new tube source, I normally buy from, has these tubes, priced rather reasonably, like $3.00 or $4.00 each, because of limited demand.

[jr_tech]

THANK YOU!
I dug around in a couple of coffee cans that I labeled "1 volt tubes" and actually found a 1D5Gp.

jr

[dieseljeep]

Originally Posted by jr_tech

THANK YOU!
I dug around in a couple of coffee cans that I labeled "1 volt tubes" and actually found a 1D5Gp.

jr

Originally the first number in the tube type was supposed to be the filament or heater voltage, but that didn't seem to hold true. A classic example was the locktal tubes. The 7 designation was 6.3 volts and the 14 was 12.6 volts. All the other locktal tubes, seemed to be correct.
It must've been a Sylvania thing.

[Tubejunke]

Originally Posted by wa2ise

Well, depending on how interested you are in the girlfriend, I'd build the AC powered power supply. And replace all the wax caps in the radio, and any electrolytics too.

Actually, of all of her hot headed Irish ways, she accepts the fact that she has no clue when it comes to dragging home old electronics. One day she will bring home the mother-load cache of Catalin plastic as the good side of an Irish girl is that good luck charm thing going on. She is the finder of that Westinghouse "Little Jewel" I posted about. One of my nicest sets!

But yeah, she has bombed before and I had to re-gift an UGly old RCA radio-phono combo back to a thrift store. Nothing on the thing worked and if it did I would have still found a way to lose it! Sounds bad I know, but I'm no fan of combo anything. I gave my neighbors a real nice 40s Zenith combo with the "Cobra" head stylus in working order. In collecting you reach an unfortunate point where you must get rid of something in order to drag more somethings back in.

As far as building a power supply for this ugly thing goes, it would definitely have to be out of love of the woman and not the radio as I don't think that the thing is worth the cost and labor of building such a thing unless I were to decide to go ape ca ca into farm radios.

Heck, I have an old 1940s Lambda DC supply powered by an array of 6L6s and a few miniatures. Perhaps it will work long enough to provide the voltages. OR you can bundle flashlight batteries I hear. Expensive once again.

[dieseljeep]

Originally Posted by Tubejunke

Actually, of all of her hot headed Irish ways, she accepts the fact that she has no clue when it comes to dragging home old electronics. One day she will bring home the mother-load cache of Catalin plastic as the good side of an Irish girl is that good luck charm thing going on. She is the finder of that Westinghouse "Little Jewel" I posted about. One of my nicest sets!

But yeah, she has bombed before and I had to re-gift an UGly old RCA radio-phono combo back to a thrift store. Nothing on the thing worked and if it did I would have still found a way to lose it! Sounds bad I know, but I'm no fan of combo anything. I gave my neighbors a real nice 40s Zenith combo with the "Cobra" head stylus in working order. In collecting you reach an unfortunate point where you must get rid of something in order to drag more somethings back in.

As far as building a power supply for this ugly thing goes, it would definitely have to be out of love of the woman and not the radio as I don't think that the thing is worth the cost and labor of building such a thing unless I were to decide to go ape ca ca into farm radios.

Heck, I have an old 1940s Lambda DC supply powered by an array of 6L6s and a few miniatures. Perhaps it will work long enough to provide the voltages. OR you can bundle flashlight batteries I hear. Expensive once again.

If your power supply will adjust to 67.5 volts, it's good tor the B+.
To provide the Filament supply, three D size flashlight cells, connected in series, for 4.5 volts.
That set uses a bias cell, that's probably bad by now.

[radiotvnut]

It requires some extra effor to either build an AC power supply or battery pack for these farm radios; but, I still pick them up when I can. Most of them lack in audio power; but, many of them are more sensitive than a 5-tube AC radio. This is likely because these farm sets were geared towards rural customers who did not have electricity and who often lived a fair distance from a radio station; so, they had to be sensitive. One of my most recent farm radio finds was a circa '39 Detrola-built Truetone that also contains a wind up phonograph. That one actually sounds decent and is sensitive.

[toxcrusadr]

You can buy or build a power supply specifically for running all sorts of battery radios. A voltage adjustable (1V, 2V, 6V etc.) and B adjustable from 67 to 90 and sometimes higher. So you dial up whatever you need for the radio you want to play.

[Tubejunke]

I guess any way I go it just doesn't seem worth the time or money to cobble or buy supply which I will never use except to verify whether or not this thing works. If it were one of the beautiful old T.R.F.s I have seen or just beautiful I might do it, but I don't really even like the thing that much. The output stages were evidently weak in these things. Just too many cons.

The pro is that this has been a very informative thread. I never even knew what the A and B supplies in these old things did. If I ever run into one that I really like, instead of automatically walking away I can consider these options. I noticed nobody talked about multivibrators. Perhaps because we were (for the most part) talking about AC based supplies.

Maybe I'll drag out all two tons of Lambda DC supply that I have thus far had absolutely no use for and see what it will do. I should be able to dial in most any voltage within it's limitations which are much higher than we have mentioned. I have wanted to use the rather industrial looking Lamda for some time, so maybe all of this is meant to be. I still don't like the looks of this FARM radio! LOL!

[dieseljeep]

Originally Posted by radiotvnut

It requires some extra effor to either build an AC power supply or battery pack for these farm radios; but, I still pick them up when I can. Most of them lack in audio power; but, many of them are more sensitive than a 5-tube AC radio. This is likely because these farm sets were geared towards rural customers who did not have electricity and who often lived a fair distance from a radio station; so, they had to be sensitive. One of my most recent farm radio finds was a circa '39 Detrola-built Truetone that also contains a wind up phonograph. That one actually sounds decent and is sensitive.

The farm sets also had an antenna coil, instead of a loop, just for that reason.
A long wire antenna and a good ground, works wonders, to this day.

[DavGoodlin]

I have most of those tubes but did not know what they went in.

One caution I have read about farm sets is that, when you have the tubes warm, never switch it off then back on right away.

For "A" battery: The 2 volt tube heaters are usually in parallel and will load two D cells with only 300 ma of current based on the tube data, so you will need a dropping resistor of about 1.6 ohms.

For "B" battery: Daisy chain eight 9-volt batteries together, you'll have enough current to drive the tube plates.
I have a Sears 757.421 mini-tube "pocket radio" from 1955 that only needs 45 Volts, but all those batteries will not fit inside

What makes battery-tube sets fun for nighttime DX is, you can take them outside far from buildings and 120 volt line interference!

[Electronic M]

If you have a 6.3V and a 12.6V filament transformer laying around (wall wart supplies can be parted out if ya want), some 1n4007s, spare filter caps, a couple of LM317s (or whatever that adjustable regulator radio shack stocks is), and a decent assortment of resistors you can build a cheap supply for that set. Connect the 6V xfmr primary to the power plug, connect the 12V winding of the 12V xfmr to the 6V winding of the other full wave rectify + filter the primary of the 12V xfmr (which should give ya about 85V) regulate that down to 67V DC with a regulator CKT. Now fullwave rectify and filter the junction of the two low volt windings, and build another regulator circuit for the filament voltage.

Cheap and simple (also a fun exercise in power supply design).