How to add Bluetooth to an Antique Tube Radio

[@spiritualawakenings6251]

I have several old tube radios and am considering adding Bluetooth and FM to my Zenithh 1935 mod 807. Thanks for the video it has helped me make a decision to go forward.

[@jp040759]

If you have died from doing something after watching Ron's channel please leave a comment below. Thank you.

[@AMStationEngineer]

Yeah, but there are lot's of dillweeds out there, and even I would cover my tail. Although, I do not know what the heck tomorrow may bring, the uncertainty is a b_ t _h....

[@jp040759]

@@AMStationEngineer Tomorrow will bring lazymans home made pizza on flour tortilla and what ever toppings lying around that seam pizzaesque and for dessert a chocolate cake from cocoa powder and crap around the house from scratch. I hope they come out. The biggest risk is if it doesn't go well will I use a weeks ration of T.P. caused by the aftermath of a huge pizza and cake fail. LOL.

[@greggchapman2677]

Most old vacuum tube radios have Automatic Volume Control feedback to the IF section. What does adding Bluetooth do to that feedback loop? It also comes from the volume control.

[@steelcity321pb6]

This is one of a few ways of adding Bluetooth to a Vintage Radio. I like how you have achieved installing it into your radio: a very neat job my friend. There are a couple of minor, but important points I’ll raise here: your method, which I’m sure works fine, is suitable for AC only radios. Alternative measures would be required for AC/DC radios like introducing, among other things, a one to one matching transformer in the audio line for isolation purposes since the neutral side of the mains is usually strapped directly down to deck. Low voltage mains plug adapters incorporating step-down mains transformers are fine for the purpose you are using them for, like in this instance, but there are Switch Mode Power Supply types (usually designed for a specific device) that might be used for this purpose but they might not be isolated, consequently they could be lethal - due to technical reasons I do not have space here to talk about. Those types of low voltage mains adapter are particularly hazardous if used with AC/DC radios. One sure solution might be to make a basic regulated 5 volt D.C. supply powered from the 6.3 volts parallel valve heater supply only, put through a D.C. to D.C. converter, for powering a Bluetooth devise (see Electronics Old and New videos for a clearer understanding if you are not familiar). You can use I C chip switching, possibly adapted to work in conjunction with the Gram switch, but I’m now going beyond the scope of this comment. Just a couple of points, for what they are worth my friend. Regards, Phil.

[@rciancia]

Thanks Phil and you are right.. this is or AC sets only. I chose to use a separate supply as I want it to be reversible, and a home made powered supply would work for sure.. many a future project :) Thanks my friend, cheers !!!

[@odannyboy3338]

Thank you so much for this detailed tutorial! Yes there are so many ways you can give some life back to these old radios, but I think this one makes the most sense for many reasons!

[@AMStationEngineer]

What about shielding, as for "killing the filament", I've seen old Philco's which remained on from the day they were new, until well into the Reagan Administration. Each had the "light bulb filament saver, they were quite common around Philly. It's the on, and the off, which kills filaments, CRT's, with some high output stuff excepted....

[@rciancia]

I agree...Power on and off kills most electronics, including modern ones..... thats the real enemy... :) thanks Tim

[@LarryDeSilva64]

Thanks Ron. That is a pretty easy was to add blue tooth to and old radio.

[@brmagyaros]

Just saying a suggestion. You can avoid the switch by adding two 470 ohm resistors on each RH LH wires tied together on high side of volume control. Shield to low side. Bluetooth receivers cut off AM signal automatically. I do this all the time on AM tube radios and it works great. I did 2 Motorola radios this way lol.

[@harrybond007]

Don't understand how it cuts off automatically?

[@DRake-jt2zs]

I have a RCA Victor that has a phonograph input on the rear of the chassis. Is there a reason not to install a switch in its place and connect Bluetooth here?

[@rciancia]

That would work perfectly. Just make sure you connect the Bluetooth jack in the right place and it will work great

[@AMStationEngineer]

Do you ever have to isolate/shield on these older radios, as they are hell with regards to motorboating, and anything even close to the oscillator???

[@markscheibel9723]

Great video! Straight connection from the jack to the speaker? Thank you!

[@johnsweda2999]

Or you could just switch it directly from Bluetooth without any external switch just find the trigger on the IC and wire in that way. Is the socket necessary I don't think so what you going to plug into it? Works well in jukeboxes just connect it past the op amp or the first stage tube

[@rciancia]

Yes John.. there are many ways to do this.. The way I am doing it like really turning the radio into a mini guitar amp.... Lots of ways to do this... thanks

[@chuckgloman7535]

Where on Amazon did you find the 3mm jack for the input. Yours has an open back. All the ones I've seen have closed backs. Thanks

[@rciancia]

Search Amazon for this text "CESS 1/8" 3.5mm Mono TS Female Jack Socket with Switch Panel Mount (LW) (10 Pack)"

[@chuckgloman7535]

@@rciancia Thank you!

[@WhoooshS4]

Thanks for posting this, and yes there are lethal voltages inside the cabinet. Wondering if anyone has thought about, or if it's even possible to use the DIN Jacks where the Tape/Phono In on the rear of some of the nicer units (I have a Normende Fidelio 58 for instance) where you can adapt the 3.5mm out from any common BT Receiver/Transmitter to the DIN Jack in on the Radio? There's only like 5 pins on those, seems like you'd just have to pin it out correctly and it's already a low level input. Thoughts?

[@kwacz]

gosh I hope that not a hot chassis radio. Most AA5 radios are hot chassis. They also switch the neutral not the hot on some of these leaving the chassis at line voltage when on or off depending on which way the plug is inserted into the wall. Isolation transformer should be used for all hot chassis radios even if a polarized plug is used. Something inside the radio could still fail leaving the chassis hot some day and you DONT want to find out the hard way.

[@luisverissimo8510]

Hello !! Nice tutorial !! Some tubes radio has the connection at the back for a turn table Can we use that ? Thank you

[@peper0nipizza]

I was wondering this too! Does anybody know?

[@goingjag]

@@peper0nipizza The problem is you need to isolate the input from the ground. There's another youtube video about using that input for bluetooth. As Ron says you need to know what you are doing because the ground can become hot on old tube radios.

[@bobl1636]

There are a few challenges , one is to ensure that you isolate the radio chassis from the bluetooth power supply. This can be done with a dc to dc converter. The other is to balance the stereo output of the bluetooth with resistors to sum up to one output and have that output go through a coupling capacitor and then tie into the volume control. This way the coupling capacitor will minimize any dc that could be present in there.

[@bigwillydier]

FNG here: On the schematic for my radio (RCA 3-X-535), I think my R1 is a potentiometer (resistor with an a third leg going into it). It's the only one like it on my diagram. Is it pretty safe to assume that's where I'd need to inject my signal? Also, fear not, I've heard and read the warnings. I'm not going to be digging around in there until I've done a lot more research on the safety aspect. Just trying to plan things out at the moment.

[@rciancia]

I am trying to find the schematic for this without much luck so I can help you. Can you paste a link to one so I can take a peek ? Thanks

[@bigwillydier]

KZbin just isn’t going to let me post anything sort of link-related, apparently. Fourth or fifth try. Found a place called “radio museum” (an organization) and searched for 3-X-535.

[@bigwillydier]

Oh yay.. it finally let me reply with hints of where I found the schematic. Thank you for being willing to take a look! I was hoping it was an easier question to answer.. lol

[@old64goat]

Yes that is the way I would do except I do not have bluetooth, I just plug in an MP-3 player.

[@rciancia]

Yes, there are many ways to do this..... lots of ways.. I find this way works for me and is least intrusive to the radio. Thanks Bill

[@jp040759]

Bill I added an accessory jack on a buddies 1957 Seeburg jukebox to hook up his MP3 player. It sounded so good I could not believe it.

[@Rainbow__cookie]

Or you can also use the turn table port if it has one

[@rciancia]

You are correct- same concept and good call out. Thank you!!

[@tubeDude48]

Also see: *Jim Burns* He does full restorations.

[@greggsvintageworkshop8974]

Thanks for the video Ron! Great stuff as always!

[@rciancia]

Thanks Gregg !!! Believe it or not, I could not find one video on YT on how to do this, so decided to go fo it.

[@mmckenzie000]

Ron: Very neat concept. Can/will you post the information about what we would search for on Amazon to get the same Bluetooth device that you used in this video? Thanks in advance. Mike from Georgia

[@rciancia]

Michael search Amazon for this one. The price has gone up a little, but it works great.... thanks man SMAKN APT-X Bluetooth 4.0 Audio Receiver Board Wireless Stereo Music Module

[@TheMangeGrain]

Thanks. I like this simple and reversible mod. But I have a long term concern about it. Tubes were designed with a limited lifetime, maybe 1000-2000 hours. They wear out progressively and the radio slowly becomes less sensible. If you don't cut them when on line-input mode, the RF and IF tubes will wear out for nothing and that's a pity : they're not produced anymore.

[@davidhamm5626]

They have to be on, they are part of the voltage string...

[@msf60khz]

Not on AC operated equipment, where they are in parallel. @@davidhamm5626

[@chuckdearman1243]

He showed how to install the wiring to the switch but didnt explain the connection from the jack?

[@TarreY13]

I do I want to climb both of them together

[@randallball2340]

Great video! Thanks for sharing this information. One quick question. When you mention the shielded wire, is that just a single wire inside shielded insulation, or are there more than one conductor inside the shield? Not sure if that makes sense or not. Thanks!

[@goingjag]

He's implying a single wire with a shield. Shield to ground (chassis) unshielded center wire to the cap and switch. As Ron says if you aren't sure you probably shouldn't do it. The ground can end up being hot on an old tube radio.

[@ohioman3704]

I am planning on installing a phono input in my Grunow 761 which does not have one yet my Grunow 1291 does but you have to reach inside to the front of the chassis to plug in or unplug anything from it and numerous times I have burned my arm on hot output tubes on that set to plug in like a bluetooth preamp, record player etc.. man what a lousy design.

[@mmckenzie000]

Thanks!

[@jp040759]

HUGE PSA This is no joke. You have to be careful with wall warts these days. The old style ones with transformers to drop the mains voltage are OK. They are isolated from mains AC power due to the transformer. A lot of the new cheap chinesium switching style power supply wall warts and USB chargers out there are being found to be non isolated from mains. You can get electrocuted by them, not to mention killing any gear you plug them into. See bigclivedotcom and diodesgonewild KZbin channels for many videos showing these dodgie style wall warts and how to test them and various other products not isolated from mains power also. Be safe out there.

[@rciancia]

Good info JP.. will check it out. Thanks

[@jp040759]

@@rciancia People have died because of this. Some gal went to talk on her phone while charging it and went to soak in the tub and that was all she wrote. The charger was not isolated from mains and it killed her.

[@bobl1636]

Add a dc to dc converter to isolate the power supply output to the device being powered

[@jp040759]

@@bobl1636 Not all inverters are isolated from mains and/or outputs are not isolated from their inputs. Most are not. Ground or common is usually common to input and output of inverters.