I gave the pinouts on the 9th. and at one stage suggested it should perhaps be a 6SK7 same pinout.

You look at the wiring side of the octal socket and read clockwise. There is a locating spigot on octal tubes & bases.

Left of the notch in the socket is pin 1 Right is pin 8

In the case of 6AC7 & 6SK7 I would expect pin1 to be earthed to chassis. That is either the body (metal) or shield.

Pins 2 and 7 are the heaters and one of those may also be earthed.

Pin 3 is grid 3 (suppresor)
Pin 4 is grid 1 (control grid)
Pin 5 is cathode
Pin 6 is Grid 2 (screen)
Pin 8 is Anode

Radio may be a Howard in reallity? will look

Hey how do I send pics!

How about a youtube of stills


http://www.youtube.com/user/billycamera#p/a/u/0/AolbmNBpT34

Photos for inclusion in posts can be either e-mailed to me or linked from a photo hosting service with the correct tags - details in posting guidelines. My e-mail address is on my profile page.

AutoCad drawing of Octal base sent to Brad.

NB Base or wiring side, inside of pan not what you see on the top of the chassis.

Marc

Set is now making radio noise. The sockets in this are not of good design or quality.

The EL83 let go, and set is now working with a salvaged 6CK6. This failure may have been contributed to by the fact that the suppressor (pin6) 6CK6 was floating, in 6M5 it is tied to the cathode.

As I said previously, not pin interchangeble & the supplier should have been aware of that and I hope mentioned it.

100pF on Triode (Det / audio) had also let go and a couple of resistors failed to impress.

Marc

Hi all....

Am further down the track with this. Have got a set of 2nd hand but tested tubes. Will not install until I can replace caps but am having trouble finding the caps!!!
Especially the 24MFD 350V.
For the 16MFD 350V I can get a 16MFD rated at higher than my 350v so will this be OK?
Pinouts of the metal tube (which is definitely a 6AC7) are:
Pins 1,2,3 and 5 are joined
Pin 4 to one lug of the (coil?) - the big shielded thingy with 4 pins on base)
Pin 8 to other (coil?)
Pin 7 appears to be heater as it goes to all other valves
pin 6 goes to ground through 22μF cap and also to (coil?) through a resistor and to pin 6 of the 6BE6 also through a resistor.
Sorry for the fairly un-tech description!!

Nucky

More on the Precedent..

Have replaced most of the electrolytics and paper caps and done a valve replacement with some quite good results!
Now getting radio reception fairly well but needs a really good external antenna to pick up a decent signal.
There is still a little hum from the set and I also have noted a .022 paper capacitor that was attached to the 3rd pin from the right of the blank (looking from under the chassis) of the 6M5 has a broken off fly-lead so I have no idea of how to wire in its replacement (where the other end goes).

I also notice that there is some slight attenuation of volume when I touch any of the shafts of the controls (pots and switches) so am curious why this would be the case.

Ideas/suggestions welcome - especially a circuit diagram and I'm beginning to think this set is from earlier than 1955 - more like 1940's???

It is really pointless trying to fault find half a job. If all of the filters have not been replaces it wil hum and if, it is back biased and the 1st cap neg is in the wrong place it will hum.

If the chassis has 6BE8 and 6M5 it is not likely 1940's

Pin 7 of 6M5 is its anode. If there is a plate bypass cap and it has fallen off, there is scope for looking at the quality of the soldering. This cap falling off will not enhance the sound quality. That pin should also connect to the speaker transformer.

22μF 450V will be easy to get, or use the evatco 500V or Sprague's. I have had some 450V ones let go and am not impressed with their filtering. Some of the cheapies out there are crap.

Go back to my post 14th Nov. Those 6AC7 pinouts have not changed.

I would also suspect you have a poor antenna and no mains earth on the set .

At some stage the set will need re-alignment, which will likely improve things.

Get rid of all the paper and old electrolytic caps. I normally check resistors (best as) as I change caps, there are usually a few ferals.

Marc

Progress!

After some more capacitor replacements and fitting an earthed power lead to the set we now have much better sound!
Looks like I will need to replace both tone and volume pots. If these are not clearly marked, is there any way of measuring them so I can source replacements?

Would still LOVE a schematic of this set if anyone can point me in the right direction.

Nucky: Would still LOVE a schematic of this set if anyone can point me in the right direction.

I might be able to help, but after 70 posts in this thread I've lost track of what actual model is being discussed.

GTC... yep... has been going a while,
Billycamera has started of the thread naming a 1955 Breville Precedent rolltop radiogram.
Mine is badged as a Precedent and is a lovely rolltop radiogram so assume it is a Breville (although one post in this thread says it may have a Howard chassis).
The fly in the ointment seems to be the fact that my set has a 6AC7 which the Precedent (I'm told) did not have so there is a little mystery.
I have posted a couple of pics on photobucket (see my posts above for the link) and I can take some more detailed photos if required.

I have posted a couple of pics on photobucket (see my posts above for the link)

Don't really want to trawl back through this meandering thread. Let me know the post # containing your pics.

GTC... you can go to:
http://s1186.photobucket.com/albums/z371/Nucky11/Vintage%20Radio%20Restoration/.
Please ignore the AWA pics but you will find some of the Precedent chassis

A little more help, please...

Am going to replace the pots in this set. Have had a look and the Power/Tone one is a switched pot and has "Aerostat 5000 Lin" printed on it. Does this mean it's a 5k Linear?

The volume has "1 Meg Curve C" on it so would assume a straight 1meg log would do the job as a replacement.

Can someone advise/confirm/reassure???