project 1951 Pontiac Chieftain

[PhilA]

I done put my back out this afternoon so progress is at a halt for right now.

 

Phil

[PhilA]

Need a Delco 6067 power transformer.

 

Note to self.

 

 

Phil

[PhilA]

(also I will require a picture of all the tubes glowing in operation when you do get the radio )

Going over the schematic, they're all metal can tubes apart from the two in the power output section (V6GT). Not much will glow in this case.

 

A few of them are loctal though.

 

Phil

[LightBulbFun]

very interesting how the Radio uses a vibrator to generate crude AC for the power tranny

 

im guessing the tranny also has high voltage windings for the grid voltages n stuff?

 

a vibrator+Ballast is how some early DC fluorescent fixtures worked as seen here https://www.lighting-gallery.net/gallery/displayimage.php?pos=-102721

 

im really curious what RTC1 used http://www.countrybus.org/RT/RTC1.htm its said to have used fluorescent lighting, in 1947!

[hairnet]

Currently waiting at Logan to go home

 

Only rammel seen e28 with us spec bumper and the odd pre 90 Chevy pickup

 

Wasn't doing highways

 

Where's all the tat gone or is it just not in bawston

[PhilA]

It all rusted away.

 

There was a scrappage scheme style thing that happened here also.

 

Yes, the radio generates 250VDC for the plates, in the same way there contact breaker points make high voltage in the coil for the spark plugs.

 

Phil

[PhilA]

I was asked by someone else if the exhaust hotspot on my manifold works still.

 

Up inside the exhaust is a spring loaded plate, whose purpose is to deflect some of the exhaust gases upwards onto the base of the intake manifold directly below the carburetor.

 

This is to try and prevent liquid fuel from pooling below the carb as the manifolds are still cold enough for this to happen. When fuel ignites in the manifold it causes pops and bangs backwards out of the carburetor. This is undesirable and a fire risk.

 

On one end of the spindle is an excentric mounted weight, the other a bimetallic coil spring. The coil spring holds the weight up and the flap closed until there's enough heat in the exhaust to allow it to open fully and not impede exhaust flow.

 

Heating the bimetallic spring allowed the weight to fall and the flap to open. Simple but sturdy engineering.

 

Phil

[PhilA]

I showed the kids the picture of the radio I ordered; question was provided.

 

Was it in black and white back then?

 

 

What, black and white radio?

 

 

Yeah.

 

 

 

 

 

 

.....

 

 

 

 

 

 

At least I can say I didn't spawn these children.

 

Phil

[LightBulbFun]

I showed the kids the picture of the radio I ordered; question was provided.

 

Was it in black and white back then?

 

 

What, black and white radio?

 

 

Yeah.

 

 

 

 

 

 

.....

 

 

 

 

 

 

At least I can say I didn't spawn these children.

 

Phil

 

ahh nothing like a bit of good old American and millennial stereotype mixing

 

you should of said "No it was Black and green!" and whipped out a Magic eye tuning tube 

[PhilA]

No, the question just wasn't very well thought out.

[PhilA]

Well, my radio just took 3 days to travel 127 miles the wrong way.

 

USPS still reckon it'll be here tomorrow.

[purplebargeken]

Universally Pissing Shite. Seems about right really.

[tooSavvy]

Driver Hopelessly Lost, as a fall back :/

[Momentary Lapse Of Reason]

Damaged Parcels Delivered maybe?

[PhilA]

So, there's still no radio. Last checkpoint was in Minnesota.

 

I hope it's not what happened to my friend's wedding ring. He sent it addressed to Luenberg in Canada to be resized. It ended up in Luxembourg. Not entirely sure how it ended up not only in the wrong country, but entirely the wrong continent...

 

I hold out hope that it'll arrive tomorrow. Maybe.

 

Phil

[vulgalour]

UPS is just another way to spell Oops!

[PhilA]

 

Sat down and drew out the circuit diagram for the audio amplifier of the radio. I needed to get a better understanding of the circuit and how it functions.

It's a class AB phase inverted "push-pull". Standard common cathode arrangement as used by Marshall, Fender etc in their guitar amplifiers.

 

I can definitely add auxiliary in. Just trying to figure the least hacky way to do it, and have it correctly squelch the radio too.

 

Phil

[Sir Snipes]

Did you mark it and award yourself a B+?

[PhilA]

Yeah, I missed a few values of the capacitors.

 

Radio checked in at New Orleans overnight so hopefully will be out for delivery today.

 

Phil

[PhilA]

There is radio.

 

It's actually pretty clean inside, though. Looks like the original Delco branded tubes, though the output tubes are an approximate substitute, again Delco branded so probably a repair.

 

The tuner is twisted and cracked. I hope the coils aren't junk- if I can straighten it out hopefully it'll be good. It's moving slug tuned could rather than variable plate. Better for a moving vehicle and allows for the preset buttons.

 

Complete take-apart shall occur!

 

Phil

[PhilA]

Well, the loudspeaker still works. Stuck the output of my phone's headphone jack into it and was rewarded with music.

 

Good start!

 

Phil

[Zelandeth]

That looks quite pleasant to work on compared to some car radios from the era. I repaired one for a friend from the late 50s (Zenith branded I *think*) which was without doubt the most maddening bit of equipment from the valve era I had ever had the misfortune to work on. The whole experience could be summed up by comparing it to a car where you had to remove both axles and diamante the entire gearbox (without removing it from the car) to change a spark plug.

 

The fact that the thing was horiffically unstable unless the case was fully assembled and screwed on made testing a real chore too.

 

I did eventually get the cursed thing going, but made it absolutely clear that while I considered them a friend that any further work on that particular set would need farmed out to a specialist as I didn't ever want to touch it again!

[PhilA]

I have a feeling this one will be a bit fiddly to get right.

 

I just freed the tuner up. The casting that holds the tuning coils at the back is suffering from the same metal degradation that toy car collectors fear. It's not too bad right now but it's slowly falling apart.

 

The front comes off, the speaker is connected with a bullet connector to the output transformer.

Whoever designed this (Sylvania) definitely got it right.

 

The circuit itself isn't bad; 7 wax paper capacitors. One big can capacitor for input smoothing (that's gone really funny and leaked) and a bunch of high value carbon comp resistors that be replaced for high stability versions.

 

Phil

[PhilA]

Zinc pest in action. The casting has swollen in size, forcing everything out of line.

I may have to attempt to remanufacture an alternative if that one falls apart completely. It's not far off doing that.

 

Preset mechanism now works properly.

 

Q-tips and tape machine oil. Nice high viscosity stuff that clings well. Cleaned up the face a little- the screen print on the glass is going a little funny but it's still there for now. Shame it was just printed and not etched.

 

The buttons should come off. Just need to figure out how. They're designed to be pulled on so it's not a case of just pull on them...

 

Phil

[busmansholiday]

One minute you are fixing the engine, the next a valve radio, is there no end to your talents?

 

I trust when it's all fixed you'll be invited to display it at that Pebble Beach event.

[PhilA]

The same as a number of people on here, I'm going to say "It's only another mechanical device".

 

Broken down into constituent parts, an AM tube radio is a moderately simple device. Make sure that each individual section does what it's meant to do and as a whole it'll come together.

 

The car will never make Pebble Beach. Pebble Mill, maybe.

 

Phil

[LightBulbFun]

thoroughly enjoying the Valve radio restoration so far

 

especially as iv spent far too much time watching https://www.youtube.com/channel/UCJ6nWQ7UO-Lve9ji2FUNYwg restore his valve Radio and TV sets 

 

(I have an old 1950s Philips Valve radio here U131, https://www.doctsf.com/documents/schematheques/radio_anglais/PHILIPS/131U.PDF thats in good cosmetic shape, but somethings shorting the mains, verified via a dim bulb tester and a variac, only problem is iv not been able to figure out how the damn thing opens up, normally the chassis just slides out the back, but in this case theres some elaborate string mechanism for the tuner dial i guess, tying the chassis to the body, and im worried about snapping the string/breaking the mechanism)

[Zelandeth]

thoroughly enjoying the Valve radio restoration so far

 

especially as iv spent far too much time watching https://www.youtube.com/channel/UCJ6nWQ7UO-Lve9ji2FUNYwg restore his valve Radio and TV sets

 

(I have an old 1950s Philips Valve radio here U131, https://www.doctsf.com/documents/schematheques/radio_anglais/PHILIPS/131U.PDF thats in good cosmetic shape, but somethings shorting the mains, verified via a dim bulb tester and a variac, only problem is iv not been able to figure out how the damn thing opens up, normally the chassis just slides out the back, but in this case theres some elaborate string mechanism for the tuner dial i guess, tying the chassis to the body, and im worried about snapping the string/breaking the mechanism)

Ah, the dreaded word...Philips.

 

There's the way everyone in the industry does everything, then there's the way Philips do it.

 

There's always at least one really odd aspect to any set they've made, and the tuning cord setup is often guilty. I did have a look to see if it's one I have the service data for on file, but sadly not.

 

 

Phil, is the zinc section of the tuner bracket electrically/magnetically involved in the operation, or does it just hold those (ferrite?) sleeves in place? If it is just a bracket, I reckon 3D printing may well be a sensible way to get a new one made up. If it *does* need to be metal...yeah, that gets more tricky!

[PhilA]

The casting appears to do both; shielding for the center and holding the ferrites. It doesn't support the coils, that's done by rubber bungies mounted to the circuit board. The cores are free to wiggle a little.

 

Making another would be fairly easy. Block of aluminum, drilled 3 times. Steel cap screwed on the back, drilled to accept cores.

Top of block fitted with spacers for the circuit board and long screws to hold it in place. Frame screwed to the sides of the block.

 

Possibly sawn down to separate the 3 bores to reduce eddy current.

 

Phil

[Noel Tidybeard]

The same as a number of people on here, I'm going to say "It's only another mechanical device".

 

Broken down into constituent parts, an AM tube radio is a moderately simple device. Make sure that each individual section does what it's meant to do and as a whole it'll come together.

 

The car will never make Pebble Beach. Pebble Mill, maybe.

 

Phil

 

 

there maybe a problem there