Homemade Tube Radio

[boltonclown]

Nice project, The UK switchover from analogue to digital radio is scheduled for 2015 . Millions of analogue radio sets as well as audio equipment like hi-fi sets that come equipped with radio receivers . The disposal of these will cause significant environmental damage.

[TAC19jm]

wonderful sound radio !!!

good job!!!

[mlund5]

Nice to hear J. Vernon McGee on a tube radio.

[qseru82]

great job ;)

[bob505470]

its actualy probably closer to 300 vdc.

[jian2069]

any chance you can capture a high quality mp3 of you doing just what you did in the beginning of the vid? sounds pretty creepy and could be used in a game

[mig189189189]

Awesome video. Keep on with that good work!

One day youll be a millionaire radio expert!

[raccoonnyc]

The radio sounds great. Good job.

Tom, ak2b

[gate13volos]

0:04

lol

[peacetreaty7]

thats messed up homey called his radio a death trap.anyway just keep the kids away from the radio. good job

[cwr56]

BTW, that power transformer suggests this radio is not an AA5 design.

[KevinRexrod]

This is the way radio should be! I want to built something like this with AM and FM where can I get a diagram?

[Lockemeister]

Romans 5:2 great verse. I used to listen to that preacher on the radio, but I forgot his name.

[snuffy39]

This old radio preacher was J.Vernon McGee. I believe he died in the last 10 yrs or so

[NJPurling]

I have not made a superhet as yet.

A basic regenerative TRF is easiest for the beginner.

What I made uses a home wound coil. Regeneration is by variation of the 2nd grid voltage. Grid 3 is wired to the chassis.

I took the amplifier stage from a old book. As it has a 6V6 o/p valve it has plenty of power. There is no RF amplification.

I do have a full set of coils to build a superhet, plus a signal gen and 'scope so I have got no excuse not to get started.

[zacatecastambor]

i love the way the sound fades in and out and the show its perfect, thanks good video!

[s3lvr]

nice job but is this only just a tuner? you could make it much smaller like I did before 3 years and it worked

[onelasssttime]

Wow. Really nice job

[bitrex]

Do you know a source for inexpensive line isolation transformers like the one in your project? The Hammond models I've seen are upwards of $40 each, which is a bit much.

[wkat950]

How do you keep from getting zapped from crossed line wires (hot chassis) with an isolation transformer? Was your iso xformer integrated into the radio chassis? I might try my hand with an AC powered tube radio but likely will go with a car tube radio restoration first.

[madisonhack]

Chassis is earth ground, both ac input lines float. That's the whole reason you use an isolation txmr in the first place.

[cwr56]

Chassis is not earth ground. The chassis is either connected to one side of the ac line (hot chassis), or indirectly to one side of the ac line (floating chassis). Almost no AA5 sets have an earth ground connection (no 3 prong plug)

Some earlier sets had a seperate ground wire.

[ab5ni]

It's also important to note that since this is an non-grounded radio, it is also a potential shock and fire hazard. It is _highly_ recommended that you add a three-prong AC-power cord to this find-sounding radio. Otherwise, this is wonderful construction and a great sounding piece of gear. Keep up the good work :D.

[cwr56]

NOT ADVISED to add a grounded cord! An AA5 design was not designed to have it's chassis grounded. Doing so will cause problems, and poor performance. A fuse, and a polarized plug is a good idea, so the side connected either directly or indirectly to the chassis is always neutral.

Many radios were designed to have a grounded chassis. The AA5 was NOT one of them.

When properly assembled and serviced, they are no more of a fire hazard than modern appliances.

I've been servicing AA5's for years.

[ab5ni]

I just looked at several AA5 schematics, and you're right about this rig. I might note, however, that this is not usually the case 99.999% of the time. I'd also like to point out that this "radio" has its filaments being directly fed by AC. That, in and of itself, makes this radio not only a fire hazard, but most definitely a death trap, and a very poor design to boot.

(I know...cheap radio for the masses...older tech...blah blah blah.)

[cwr56]

how are series strung filaments a fire hazard or a death trap? The whole purpose of that was to reduce the cost of the set by ommiting a power transformer, which comprised about half the cost of the whole radio.

Stringing the filaments in series, and having the B+ being directly rectified from the AC line was certainly cheap yes, but not a fire hazard or death trap.

It's not like you would be exposed to those voltages unless you had a hot chassis.

[ab5ni]

Hello again, cw. Well, I won't go into all the ramifications of the "on the cheap" design of this radio, as we're both well aware of its short-comings, but I will say this: should the over-driven filament on the first tube ever let loose, such as short to the grid (which can happen, albeit not so often), you can bet your last dollar that anything connected to that tube is going to arc/short straight to that chassis. Most of these radios are will never, ever be serviced, unfortunately.

[cwr56]

99.999, not at all. Ive been servicing AA5's for years, and only a very few that people have brought me were of the hot chassis design. I usually install a polarised plug and fuse, unless there is a possibility of someone touching the chassis, in which case I rewire it into a floating chassis.

[ab5ni]

I send numerous kudos your way for doing this, too, cw! The problem is that most folks that have "there old grandparents radio" don't have any idea that these radios should never be plugged in before someone like yourself can look at the thing. The vast majority will just plug the thing in, with most being lucky and just hear a lot of bad hum. Some, however, will be touching the thing while the chassis is hot, and hopefully they'll jut be knocked across the room. Some won't, and they'll either..

[ab5ni]

survive the encounter or be killed on the spot. Also, don't forget that those old paper caps are prone to catching fire, and this can be a problem if they turn the thing on, leave the room, and the cap lets loose, catching fire.

Regards...

[cwr56]

good point on the filament, but that's the exception, not the rule. A short to cathode is more likely if the tube has one. The first tube on the hot side of the line is usually the rectifier, in which case there's no grid, only the plates. Shorted rectifiers are however, very uncommon.

I'm aware of the problems with old paper and electrolytic caps. That's why I routinely replace all of them. They are the most unreliable original parts, second only to brittle and frayed power cords.

[old64goat]

Nice job on this radio, real neat work and radio sounds great.....Bill

[bitrex]

All those sinners in Windsor, Canada! Haha, in any case I have the guts of an AA5 radio here that will be too much trouble to restore - I think I'll make a similar project.

[madisonhack]

See my previous post. Be careful with the AA5 - they didn't use an isolation xfmr; the heaters added up to 120 volts ac and the rectifiers were wired directly to input ac...very dangerous because the chassis would be hot, in that case.

[cwr56]

Hot chassis designs were only in the exceptionally cheap sets where they were too cheap use a common ground bus, and used the chassis instead by hooking one leg of the ac line to it.

Most AA5 sets used a floating chassis that was coupled to the AC line only by a .05uf capacitor and a 220-470K resistor.

I service these sets.

[donnyab]

what do you mean by a floating chassis...does that mean all grounds in the circuit as well as the chassis itself is grounded to the earth

mains ?

[cwr56]

A floating chassis is one that is not connected to the circuit at all, except by a capacitor, and high value resistor, that connects it indirectly to the ac line for RF shielding. A "hot chassis" is the same thing, but connected directly to the ac line (usually the hot side of the line), instead of through the resistor and capacitor. If you touch a hot chassis, you'll get a shock, if you touch a floating chassis, you get nothing, unless the capacitor shorts out. Most AA5's are floating.

[southjk]

great job..thanks for posting

[fryloc359]

I can just hear Nixon's voice coming out of the speaker, talking about the Vietnam war.

Cool stuff.

[hunt555fish]

do you have a schmatic and parts list for this radio?

[hunt555fish]

Where can I get the info to build an AM tube radio like that? Sure is a beautiful job.

[dllewiszz]

Very nice looking AA5! You took some of the risk out with the isolation xfmr. Didn't you always love it when the line cord was flipped and the chassis was "hot"? I'll admit that even recently, when I'm in boring meetings at work, I'll often sketch out an AA5 schematic, or a push-pull amplifier, or various old-style power supplies. This is an inspiration. Tubes are like vinyl music -- they're so much more fun than the new-fangled digital/solid-state stuff.

[sidebander]

Very nice radio and definitely an inspiration to newbies.

[sq2iii]

My transceiver work good. In RX used E88CC ( mixer RX and balanced modulator for TX ) I.F amp EF183.Product detector 6N1P (Ecc85) AGC control : EC86 EAA91 6N1P.Audio amp ECF80.

Transmitter : mixer ECC85 Driver EF80 P.A 2 x PL81( maybe PL83 ) VFO is Vackar . Bfo work on ECF80...

[sq2iii]

Good work ! What tube you used in this receiver ?

[w4kwd]

Outstanding!

[radioam232]

perfect!

[coondogtheman1234]

thats an awesome rig sounds great too, can it take a line in signal like from a cd player or ipod

[coolbluelights]

Awesome!! whee did you get the schematic? I'd like to build one of these, all it needs now is a nice cabinet ^.^

[AllAmericanFiveRadio]

Wonderful job! Beautiful wiring and very neat work. Terrific!!

[damusician]

that is awesome! someday i want to build a stereo tube amp. where can i get a schematic for building circuits for tube amps?

[mariopica]

Thank you for you answer. It is a very interesting radio indeed. Love it. Here in Brazil is very hard to find parts to make something like this. Congratulations for your nice work and beautifull radio. Best regards from Brazil. Mario.

[mariopica]

Very cool radio. I would love to have enought know how to built one too.

May I ask you how much did you spend on it?

[WDX7770243546]

sooo cute, I love tube radios.

[DariusFranke]

I assume this is similar to an "All-American 5", but for curiousity, do you have a schematic? How did you wind the ferrite coil? etc..

thanks,

DF