High current draw was the norm for these sets. That was why Dad wouldn't let you play the radio when the car wasn't running. Dead batteries were common with those who didn't think about it. I have rebuilt many of those switched over the years. A surprising number respond to a simple clean and lube with a Q-Tip, cleaner, and wee bit of synth oil. My eyes aren't up to doing this much now but I did recently do the identical thing with a nearly identical power switch in an old Wollensak recorder. I have also transplanted switches from old volume controls into these. Repair shops had to be pretty flexible back when I started. You never knew what was going to walk in the door and people were not taking "It's too old/odd/out of production," as an excuse. Everything from primitive early tube sets to the latest solid state gear was expected to be repairable. To them you just weren't "good enough" back then. Many miracles were performed back then.
Eh, 90 watts is too much. A typical fault is a leaky electrolytic smoothing cap. I've had some that would draw 10 to 20mA of leakage. Not enough to totally kill the radio, but enough to cause a ton of wear and tear on rectifier/vibrator, and to make power consumption skyrocket.
@@mfbfreak I think you are misunderstanding how vacuum tubes work (amount of current required to make a robust, vibration resistant cathode glow, and amount of current at 6 volts required to step up the voltage to the requisite high anode voltage) while also failing to understand the difference between a few tens of mA's of leakage here and there, versus the reasonably normal 10A draw of a unit like this running entirely on a 6 volt supply. It's not like powering it from mains AC, whatever flavour yours may be, 12 volts, or high voltage batteries; and they weren't designed to be economical on power usage, unlike portable valve sets of the time.
Ken Phillips I recall as a teenager in 1961 tuning a radio in a 1952 Chevy which had sensitivy and selectivity I have only seen paralleled in communication receivers. Someone told that this radio design was first born in a 1947 Cadillac.
@@12voltvids I get that they consume a lot of power, but 90w is too much. That's the amount of power a stereo tube radio with FM draws. A conventional AM radio draws about half of that, 60w tops. The various tube car radios i had, i could supply with power from a 4-6 amp 12v power supply with ease, with a big dropper resistor if it was a 6v radio. Your power consumption makes it seem like it's actually meant for 6v, (been there, done that, it just made the vibrator very loud until the fuse popped - radio survived) or there are some very badly leaky caps. You could check the filament current and anode currents of the tubes from the datasheet, and maybe add 10w to that for the inefficiency in the vibrator. That gives you a good ballpark power consumption number.
I have worked on car radios going back to 1936. They were designed to be pretty rugged since they were outside in heat and extreme cold. Given the technology of the time (wax caps!) it was amazing how long they lasted. They were also nearly identical to "farm radios" of the pre-war era. Both used the vibrator/step-up transformer system (yes, there were other designs) to operate circuits at high voltages. The one thing that I and others working on the early ones hated to run into were synchronous vibrators. These switched both the primary AND secondary of the transformer and eliminated the need for a rectifier tube. They were usually found in the upscale makes of cars. Getting replacements became very difficult. The workaround in later years was to rewire the secondary to eliminate the vibrator and install silicon diodes. It could then be run on just the primary of the vibrator or a regular vibrator installed (not a lot of fun.) If you went to car shows in the 70s you could not only find the parts but you could see kids modifying sets at the dealers' tables. The other big issue was bad speakers/field coils, but that's a topic for another day.
When I was a kid, we used to like to sit in the car in the front yard and play that radio, dad would get so pissed because we would run the car battery down. Definitely a 6 volt system in 48, my first car was a 50 Ford Custom, it was 6 volt as well, I used to go to the junk yard and look for "better" fancy radios that I could stick in my old Ford to customize it. I found an old Chrysler Imperial Radio with motorized tuning that I installed, it had a 2 speaker system so I ran a wire to the back deck and went to the city dump where I pulled another car radio speaker and mounted back there, sounded great for the 60's. I also replaced the front seat with one from a Rambler that would recline on both sides (2 door car) so the whole car made into a nice bed, it was great for the free love of that era, I got a lot of tail in that old Ford, wile tuning in to the KOMA good guys who spun the wax with the greatest hits of the day, came in good after dark all the way from Oklahoma City way up in North Dakota.
I re-did a '50 Hudson radio (made by Zenith) last summer for a friend. Vibrator in that one was pretty well clapped out. Had to file the points in it to the extent that not much was left of them. Ended up getting a solid state vibrator kit from WJOE radio, and used a 4 pin tube socket as the base. Worked very well. One of the critical caps I remember for those was what they call a buffer cap, that helped both regulate the frequency, and minimize contact arcing in the vibrator. It's an odd value 1.6Kv cap, but from what I read, if they're bad (which they often are) the mechanical vibrator will burn out quickly.
This is a Transitone F-1740. The circuit diagram can be found at nostalgiaair.org under Philco. Interesting to note the field coil is listed in the parts as not replaceable! Luckily it works, bad paper caps and all. Need to find an on/off switch or try to fix it. Great bit of vintage technology there Dave and thank you for showing it.
Field coils in a lot of these became not replaceable as speaker frames went from the screwed-together types to the later spot-welded type. Back then you could actually buy the cone, voice-coil, and spider or diaphragm as separate pieces and repair the original speaker. When the cost of labor went up after WW2 it just became far cheaper to replace the whole speaker instead of paying someone to do the fiddly work. You can find the lists of speaker parts in early Sams' manuals for the first 5-6 years of their production.
It's cool. The owner just wanted to get it running. Changed 5 caps in it (yes the buffer cap was one of them) to make it run. He plans to sell it and just wanted to be able to sell it as a functional radio as opposed to unknown condition. This makes a difference is what he will get for it obviously.
They got you in this one. I grew up in the 60s and it was all 12 volt by then. Cars didn't last that long either without major work. Amazing the radio kept running. Did you know Motorola started in car radios? The name was a twist on victrola for cars hence motor ola.the first ones were huge and used remote tuning.
Same here. My first car a 62 valiant. All 12v by then. For some reason I thought they went to 12 vokt earlier on american cars as my cousin was a collector and had a bunch of vintage cats standing from the 30s through the 60s. His were 12 volt but he converted them all to 12 volt systems. The only 6 volt systems I remember well was the old vw bugs.
@@12voltvids yes I watch Jay Leno and he upgrades all the cars he buys to 12v. It means better charging too. I remember switchable radios but they were solid state. I think they could go 6 or 12 positive or negative ground. Another thing, the old cars had cotton covered wires so the harnesses all need replaced. Not many alive that remember cars of the 40s so the value goes down as collectors die off.
This radio is a diamond in the rough. It is complete and no one has been inside it. If the owner takes it as is, I can understand that but you should change out the vibrator buffer cap as a good maintenance item. It will spare the vibrator relay contacts from welding together down the road, prolonging its useful life.
Yes I am aware. I don't have one at the moment. I have done the coupling caps so far, just to get it working and once I talk to the owner he will decide how much further to go, but the vibrator suppressor cap needs to be replaced as you said.
This was a starting point. Now that I know that it will work I can give the owner options. He is restoring the car it came our of, so he will be I am sure willing to spend money to do a full restore. When it was brought over he said "have a look at this and see if it will run.
No doubt the same folks who built that radio had been building mil-spec equipment for the war effort just a few years earlier, so it follows that it would be built like a proverbial tank.
With the old car generators that only put out 25-30 amps, the headlights would almost go out while sitting and idling with a load like that. I remember jumping off cars that sat for only 20-30 minutes with the radio on. Things have changed just a tad.
Most (all?) of these sets could be pre-set by the owner. On a set like this, the presets had to be done in sequence: Push for number One position. Pull out the selector button. Manually tune to desired station. Push button in to normal position. Select next position, repeat. Remember that with most sets you had only part of the band on each button/position - you couldn't set the first button to 1600, for example, it was only designed for 540 - 750 or so. Of course not all were identical but because cars changed hands and owners were moving all the time a simple method of reprogramming was essential. You can find instructions and service info on several old radio sites.
Nope, the chrome piece on the plastic bezel is pulled off, 2 screws are removed and the plastic nose piece removed. Under that there are 5 slugs and 5 tuning capacitors for the presets. Some tuned to the low end of the band and others to the high end. My Marconi table radio from the 40s is the same.
@@12voltvids That was why I said "most." My old Zenith had the same arrangement for setting its buttons. The problem with this design for use in a car was A. knowing about it and B. having the tools to do it. Households were not as likely to have them back then. Yes, the needed tools came with the radio when new but these always got lost over the years and miles. I shudder to think about some ham-head/fist trying it. The buttons would just get abandoned after a while and manual tuning would be the norm if a car left the area it was sold in. Word would get around about these and it made sales of new similar designs drop. Yeah, a dealer could do it for a customer but that was another disincentive. $$$
@@RuneTheFirst To set them you just need a slot screw driver. Pop the chrome node off and then remove the 2 screws under it to remove the plastic face. The 5 presets under that. When a car was new the presets would have been set to the local stations for the area, and to change them would have usually meant a trip to the dealer. There was always the manual control that could tune the entire band.
I knew a guy who had a valve radio in his car. The car was a 1950's Rolls Royce. Unfortunately some window fitters dropped a window from a sixth floor of a block of flats and it landed on the roof of the car destroying it completely.
Great save! Incredible RF gain in older equipment, generally. Modern radio makers ( including satellite radio) could learn a thing or two from this. I like my Sirius XM satellite car radio, but every time I come across high power lines it cuts out.
That’s pretty cool I have 2 mono car tube amp from the 50s that have speaker housing around it and looking forward to restoring this thanks again for video
Oooo, you got new screwdriver set, wow. I bet it is not convenient to work with. It is heavy due to extra bits in handle. Your old Sony one was light weight and efficient. Good work in Covid 19.
Great video and car radio thanks for sharing. On the vibrator I have replaced loads off them with a mosfet multivibrator it’s no big deal. I restore the odd bit of valve gear here in the U.K. I do like the styling of your American radios, the stuff we made in England is almost without exception very drab in comparison. I do import the odd radio from the USA as they are still so cheap but they keep getting held in customs etc as they believe they contain hazardous materials. Total crap unfortunately. All those capacitors are bad with the only exception being any Mylar ones but they are also now suspect given their great age. I really wanted to push you out the way and get my hands on it! Best regards Chris
Well this one is not being totally restored at this time. The owner just wanted to see if it would work, considering it has been sitting for 60 years in his garage. He pulled it from a wreck 60 years ago. He wants to get the plastic pieces to restore it and sell to a collector not use it himself. He doesn't have a 40 Ford which is what this came out of, he has a 32 ford that he put a 302 in.
Yes I figure that out. Was not in the final cut but it draws 8 amps at 6 volts. Incidentally I ran it at 9, not 12 as I had the limiter on. That is about 1 over what it would see when the engine if running so no big deal.
@@12voltvids Thanks for your reply. The opening minutes of your video put me in a panic - figuring that 12 volts, being double the proper voltage for the radio, would quickly zap the filaments of all those hard-to-find vacuum tubes - and that would be unfortunate!! I think that overloading your 12-volt bench supply down to 9 volts or so is what saved them.
@@davem147 I totally forgot about the old cars being 6, but no biggie as it was limited as to what it could draw. I knew all the old german cars were 6 as we had a few when I was a kid, but all the american cars my dad had were all 12, but then the oldest he had was a 55 olds and GM had already switched.
@@12voltvids 1955 was the big year for transitioning from 6 to 12 volts. A few of the better cars went 12 volts in 52-53 (Buick, Cadillac, Packard, etc.) while some went that route before the war and the dependability in cold weather and less issues with cables and grounds made a big impression on the market. 6 volt systems were offered as an option on vehicles like the Jeep and some truck lines where fleet owners had already invested in resources to handle the batteries. The option disappeared from the Jeep line (except for export) in 1964-5. Europe stuck with it for small cars until late in the 60s. We had a bunch of 6-volt VWs pass through our hands into the 70s. (VW went 12-volt with the 1968 line.)
No it wasn't. It hasn't been used in 75 years. The guy that brought it over does not own the car. It came out of an old car that was wrecked back in the late 40 and had been in storage. He only wanted to see if it worked as he was going to sell it to a collector. They were not reliable. Tubed would pop all the time being banged around in the car.
The thing with tube gear it you can run it at far higher voltages and nothing happens. In those old cars the charging voltage was 8 to 9 volts. Those radios ran just fine on 12 volts. When i was a kid I had one and used to power it from a 12 volt battery. The sensitivity was fantastic and the higher viktage gave higher output volume. Used it for years. Was out of my dad's old car from the 40s. The tubes lit up bright and it came on almost instantly.
The GE model 250 am portable radio used loctal tubes and a vibrator to convert 2 volts dc into 125 volts filtered dc to supply the B+ voltage for the tubes. The 2 volts were supplied by a lead acid battery to provide filament voltage and input voltage to the vibrator. I serviced this model The common problem was the vibrator points dirty or out of adjustment
My 1940 Marconi table radio has slugs. I have some footage that was cut when I was trying to get into the front of it to get at the volume control I will tack into a video later.
Also, I didn’t know Philco made radios for Ford that far back. Ford bought Philco in 1961(?), and later sold Philco to I think Sylvania in I want to say 1973(?). I remember that my Mom’s 1973 Mercury Comet had a Philco-branded pushbutton AM radio.
have a AM only out of a 1967 Ford Mustang (7TPZ) single speaker output. It powers up, has plenty of audio but its static and with sounds of oscillations as I tune across the dial. With a 5 foot piece of wire I was able to tune in 1 station at 920KHz weak. Based on a portable radio I have the AM radio should have received it much better. If I connect the antenna to an outside wire antenna I lose the station as though the radio was being overloaded. I could use some tips for troubleshooting. I am wondering if there is problem with AGC in the I.F. that might not be working right, (Cap or diode) . There is only 3 transistors and checking all 3 give me similar voltage readings with my meter in diode position of .295-.3v base to emitter and base to collector. Not sure for these transistors if that is normal. Collector to emitter is around 1.4v. There is a germanium diode near one of the I.F. cans. Forward bias was around .3v. Would would cause a lot of oscillations while tuning. I noticed if I lower the supply voltage its not as bad but the audio output lowers too. Any tips would be appreciated. thanks
Also there is a cap across the secondary HV side of the step up transformer. Was that the one you meant, Ian? If those go its like a dead short for the vibrator contacts, and they then weld closed, causing the primary to burn up. Always happens suddenly without prior warning.
@@blitzroehre1807 Secondary goes directly to the plates on the rectifier tube. Snubber is across the primary and it was replaced with 630v in series to get voltage up.
If the vibrator goes bad there are solid state replacements or one could probably build a circuit to replace it, similar to this one. www.portabletubes.co.uk/sitefiles/ausbatt.htm. A 555 timer, a divide bu 3 counter, and some high current MOSFET transistors would also work.
@@michaelblack5011 auto manufacturer engineers theory about ignition point wear being minimized by a certain polarity.... is what I've read. That, and there really was no industry standard. Manufacturers picked the direction in the fork in the road, and wired the car accordingly.
@@erikj.2066 I remember Chrysler being Positive ground for many, many years. Some foreign cars too. It was something you had to watch out for. I remember a friend trying to jump a 52 Ford (6v, Neg ground) with his 56 Dodge (12v, Pos ground). Didn't work and the only thing that prevented damage to both cars was that they had generators and not alternators. (Yes, it was common to jump an old 6-volt car with 12 volts. Really made that starter spin and the spark must have scorched the plugs.)
Totally agree about the 1600V cap on the secondary of the power transformer! That is called a "buffer capacitor" and its job is to help protect the vibrator contacts. If it goes bad the vibrator will fail in short order. Edit: That radio is absolutely a 6V unit. 12V automotive electrical systems didn't make their debut until 1953.
Halo! I actually find some time to look a bit inside the Sony d7 dat and the RF Amp has some normal small black brick like smd capacitors that look really nice so I put the RF amp together again. The head is clean and nice as well as the whole transport system (like new pinch roller). In the end I found out that when I press record and having an input music signal, I do not see the peak levels working, however, when I start recording, the head can actually erase the tape and also record nicely but the level is really low but when I place the recorded tape from the d7 on the dtc670, it plays better and crystal clean. So the head and RF Amp works nicely (no errors on the screen too) Now I decided to look a bit the main board and I found leaky silver cylindrical capacitors that had corotion around them. I removed them but I do not know where to find new ones. An another option would be to sell the transport, plastics and everything since they work and also they are scarce and expensive. What do you suggest?
15 amp load for a radio. Wow! I thought most ran at 8-10 depending whether it's a 6 or 12 volt. Considering that the old DC generators did good to put out 35-40 amps (a 1950 Buick had a 40 amp generator), that's still a major load. (Below 25-30 MPH you may get 20-25 amps at best). Add in lights and/or a heater fan it's no wonder there were a lot of dead batteries. This would've made a good one for Mr. Carlson's Lab.
It draws 8 @6v. I had the limiter set on my popwer supply, and forget to turn it down to 6, but the mimiter dropped it to 9 so no big deal. 1 over what it would see frm generator when car is running.
I expected the tubes to be stone cold dead, amazing that they still work :-D If the switch could be made to work for light loads, a car relay could be employed to do the heavy switching. I'm working on a leak stereo valve amp with bad anode to grid caps, testing at 350 volts and they leak bad. Like you I'm not really a tube repairer but they seem quite forgiving devices :-D
I wonder would it be worth rebuilding it to use the ZENITH Vacuum tubes designed in 1957 that have a 12V heater and 12V B+ and get it working on 3-5 Amps instead of the 15A it seems to be taking.
Thanks for this video... I told my ' electrician brother ' about valve car radios, and he didn't believe me. Makes you wonder about the power converters, and whether they'de be any use today ? TIP: If the speaker cone looks like it's about to crumble, spray a few coats of scotchgard on it ( it should hold it together ).
I've worked on Buick radios from the 40's, they were heavy and had pretty good push pull output ckts. 40's car radio's were usually 6V and that one looks like it uses Loktal tubes. I'd expect to find problems with the 6v vibrator, OA2 rectifier and the 1,600 v caps across the rectifier and the vibrator points. Then the inter-stage wax coupling caps have to be dealt with.Some of those old sets were good, you could pull in stations from Memphis in Boston. I still have a few vibrators but I think they are 12v models from the 50's.
AWOW: You might want to check the condenser cap across the secondary of the main power transformer. If that cap goes open. It will cause the contacts in the vibrator to arc and burn up.
Great video. This one is worth all my contributions to patreon for the year. Thanks for working on this old girl; I hope the owner will have you bring it back to fully usable condition. Did you rep-ace the capacitor on the power switch and what was the current draw after the four caps you replaced? Thanks Dave.
So that vibrator switch is basically a reed contact? In early times, another way used to create pulses was a device similar to a mechanical watch escapement and balance wheel, but with an electrical switch attached.
It wouldn't have been an Alternator back then, it would have been a Dynamo. Surprised it even worked with all that old capacitors, there would be a lot of leakage increasing the current. The vibrator could be done electronically these days. You couldn't leave these things on if the engine were not running, there was no way the engine would ever start again. This would be a project for Carlson's Labs. I wouldn't trust it very far, the wiring will be rotten as either rubber or cloth wires! I hope you had good strong soap for cleaning your hands after working on that thing?
I do believe I did mention the wires. The oldest radios I have worked on is an old Roger's majestic from the 20s and a stromberg carlson from the early 30s. The Roger's I had to replace all the wires as the insulation had all come off the wires. Those radios are in my collection and work great.
@@12voltvids I once opened up my mothers old Bakelite covered radio with the intention to fix and rewire it. However, when I touched the wires the rubber covered wires just crumbled, I looked at how many there were and how complicated a route they took and decided it was just not worth the bother, it was not a collectable radio and it was issued to all schools here, so it was never going to be a rare set. It was full of valves and dust and with crumbling wiring I scrapped it and got her a more modern one, in the end it was going to be safer and she could play cassettes on it, she was happy with it. Then she got a radio record player to replace the old auto change that had gone faulty when I was away working, so it was only used to play cassettes in the end.
You beat me to it. Aside from a few early model T's, alternators weren't common until the early to mid 60's. VW continued to use dynamos for a long time.
Don't need switch just hook radio up in car to ignition on power so when ignition off radio turns off. Tube stuff so durable can survive years of sitting around :)
Doesnt work properly because the vibrator contacts are on a sort of pendulum and swing hard. Mentioned it before, but solid state conversion is faster and much more effective
Blitz Roehre no not long and the frequency is kind of tuned on the vibrator to matching the step up transformer. I forget but I think the last one I did was around 100 hertz. But tuning it made quite a difference to the final output Voltage
That is so awesome to get a 1940s am car radio working again,,,goes to show u how well they were made back then,,,compared to modern units that wouldn't go nowhere near that long! I did read the other comments too about that it must've been a 6 volt car radio,,,that possibly explain how it nearly melted the leads,,and burn out the power supply,,,instead of the unit from over voltage. Good how u said you had it going again at 6 volt power for a few hours with no problems. But good luck in finding a replacement power condenser and tone switch too,,,,and re-align dial tuner,,,I like how that station preset button worked too. I guess the owner would b over the moon to have a 72 year old battery operated car radio working again restored to former glory.
Power supply is current limited so it won't hurt it. Once current hit limit the voltage drops down. I can short the leads and it will drop to less than 1 volt and still heat the wires up.
Ok,,sounds like the power supply is more advanced with a few safety features in case of current overload,,, and with voltage that drops to low as well if u do short the leads out,,as they still get hot and melt,,,that,s the last thing u want to have there,,,but now i know it won't damage your power supply unit,,but still end up replacing the leads if they melt to a point where they become hard like a solid wire.
@@nickfrench7372 the lead are very thin, 18ga. I have 14 leaving the power supply spliced to 18 so they will burn up first. A fuse link. That's how we protect the phone lines. A short length of 26ga wire between the cable and the service drop which is usually 19-24. That way if mains were to drop on phone cable it would burn. The fuse link of before the drop wire burnt up and potentially causes a fire.
@@12voltvids Yes I understand how they were thin,,not heavy duty power supply wires,,,as they had almost melted. Interesting about how the telephone wires are protected this way too.
You need to go to GRAMDPA'S RADIO. It is a company out here in ontario. He deals with vintage radio from the 20's to the 50ties. Parts and repair and replacement units.
Could have been positive ground. Doesn't matter on tube gear with a vibrator. It will create the b+ regardless of input. It's a 6 volt but giving it 8 or 9 won't hurt. Regulation on those old cars wasn't very good. Should be pointed out that the owner if this radio did not have the car it came out if. He just wanted to get it running so he could sell it as a working unit.
@@12voltvids Neither do modern cars with their super stiff suspensions and rubber band tires. Every last pebble and cockroach you encounter goes right up the spine in 'em. Best riding vehicle I've ever driven has been my '85 F150. Soft springs and nylon belted 235/75R15 Goodyears make for a comfy ride.
@@TestECull You must be driving old clunkers as both my volts drive pretty good and do a great job of smoothing our all the pot holes while still handling like a sports car.
@@12voltvids '04 Explorer, '13 Hyundai Elantra, '14 Dodge Challenger. My 'old clunker' rides better than all three of them combined and the newest one...the Challenger which is under 50k miles...rides the harshest. Modern cars ride hard. They're too stiff and they don't have enough sidewall. Of the new ones, the Explorer rides the nicest, but it's still an order of magnitude harsher than my '85 F150 is.
Yes many times tubes will fail internally but the filament will still light up. That's why tube testers check for shorts and for gas. Is the getter still good in other words does it have that silvery coating on the inside of the glass at the top? If that is turned a milky white color then air has leaked into the tube and is no longer under vacuum and it will not work.
Neg ground and 8 or 9v won't hurt it a bit because regulation on those old cars was terrible. Won't hurt the tubes one bit. Even 12 would do nothing to it, heat the filaments a little hotter. A 6 volt car would normally charge between 8 and 9 just like a 12 volt system is typically 14 to 16 volts. 13.8 is nominal now with electronic regulation but old cars it would cycle up and down depending on engine speed.
It was 6v. My bad, but no worry. Current limited which brought voltage down to 9, which is about 1 over the charging voltage when car is running so no big deal. Tubes are pretty forgiving.