New NOS Iron day.

[tribi9]

I picked up a PT and an OT

The Power transformer is from an old 60's radio. The secondary is rated at 650 VCT. It has 6.3 heater wires center tapped. 5 V winding and an extra 2 wires. I think this is probably a second set of 6.3 V heater wires. I dont know anything else about it. Not sure about the mA current rating either.

The only markings on the side of the PT are the letters TLK 2686 and right underneath it also says 6A0464

Also I found a NOS output transformer the brand name on this is "Standard"
It came with the box and original instructions. It looks really beefy as well.

The primary impedance on it is 8000 CT. Now I'm a little confused on this one. The data sheet that came with it shows that the brown and blue wire go to plate #1 and plate #2 but it also says that the red is B+ so if anyone can help me id the red wire it would be really nice. (See last pic)

I'm thinking of building an 18 watt lite with them. I'm not sure If I can build the one with the 6CA4 as am not sure if the PT can handle the current draw for the rectifier on the second set of 6.3 heaters. (Assuming those extra two wires are another 6.3 winding. Still debating if I should go with a diode rectifier.

I cleaned the PT with a little bit of WD40. I sprayed it on an piece of cloth and just wiped it down. (This wouldn't damege it if got inside, would it?)

Anyway, opininions are welcome from everybody. I'm just trying to learn here but sometimes it seems so mind numbing. So that's why I hang out here and ask lots of dumb questions.

Cheers guys and as always I appreciate your help.

[IMG:800:600]http://i114.photobucket.com/albums/n271 ... C02353.jpg[/img]

Look at how tiny the Hammond on my Vibrochamp looks in comparison yet they're both rated at 650 VCT

[IMG:800:600]http://i114.photobucket.com/albums/n271 ... C02356.jpg[/img]

[IMG:800:600]http://i114.photobucket.com/albums/n271 ... C02354.jpg[/img]

[IMG:800:600]http://i114.photobucket.com/albums/n271 ... C02362.jpg[/img]

[Andy Le Blanc]

B+ is the old battery designation, I'm always using old terms, the PS lead.
6ca4 has a 1 amp rating on the heater, might want its own fil. supply, another old term.
The WD means water displacement its good for engine parts and fishing lures
keeps things from rusting to crap in a salt water environment.
It's not ment for electrical equipment, won't do any harm unless you've
saturated the paper in tranny with it.

centralab division of global-union had a standard color code for secondaries

rd- rd/yel-rd.................. high volt w/ct

yel- blu/yel-yel..............rectifier w/ct

grn-grn/yel-grn............fil. no. 1 w/ct

brn-brn/yel-brn............fil. no. 2 w/ct

gry-gry/yel-gry.............fil. no.3 w/ct

but things were used interchangeably by various makers

[tubeswell]

The Power transformer ... secondary is rated at 650 VCT. It has 6.3 heater wires center tapped. 5 V winding and an extra 2 wires. I think this is probably a second set of 6.3 V heater wires. I dont know anything else about it. Not sure about the mA current rating either.

Only way to find out is to hook it up and see what the other winding is - could be a bias (40- 50VAC supply?? or another heater winding)

Also I found a NOS output transformer the brand name on this is "Standard"
It came with the box and original instructions. It looks really beefy as well.

The primary impedance on it is 8000 CT. Now I'm a little confused on this one. The data sheet that came with it shows that the brown and blue wire go to plate #1 and plate #2 but it also says that the red is B+ so if anyone can help me id the red wire it would be really nice.

Must be a PP OT - Brown and Blue would be the output tube plate wires for each side, whilst the red one is obviously the Pri CT (- goes to the B+ node in your filter section). Being 8k Pri Z it'd be good for 2 x EL84s or 2 x 6V6s.

[tribi9]

Thx Andy,


And no more WD on any of my amp parts.

Edit:

[tribi9]

The Power transformer ... secondary is rated at 650 VCT. It has 6.3 heater wires center tapped. 5 V winding and an extra 2 wires. I think this is probably a second set of 6.3 V heater wires. I dont know anything else about it. Not sure about the mA current rating either.

Only way to find out is to hook it up and see what the other winding is - could be a bias (40- 50VAC supply?? or another heater winding)

Also I found a NOS output transformer the brand name on this is "Standard"
It came with the box and original instructions. It looks really beefy as well.

The primary impedance on it is 8000 CT. Now I'm a little confused on this one. The data sheet that came with it shows that the brown and blue wire go to plate #1 and plate #2 but it also says that the red is B+ so if anyone can help me id the red wire it would be really nice.

Must be a PP OT - Brown and Blue would be the output tube plate wires for each side, whilst the red one is obviously the Pri CT (- goes to the B+ node in your filter section). Being 8k Pri Z it'd be good for 2 x EL84s or 2 x 6V6s.

Yes it is a PP OT. Sorry Im confused what do you mean by the B+ node in my filtering section? The tab from the filter cap that connects to the plate? Or is it the ground on my filter cap?

If it's just a center tap it can just go to ground, correct?

[tribi9]

Lol, nevermind I was thinking Power transformer when I saw the reply as I was testing the PT at the moment. Ok that makes sense. Gosh, I'm a moron!

Thank you very much.

Oh and this is what I got on the PT


Green 6.3 VCT

Red Secondary 680 VCT

Blue 6.6 V (So maybe I could go with the 6CA4 then?)

Yellow 5.1 V

Anybody ever heard of this PT's? Any good?

[tubeswell]

That PT and OT'd probably be good for a BFPR. (No need to use that other winding)

[tribi9]

That PT and OT'd probably be good for a BFPR. (No need to use that other winding)

I would but all the layouts I see for one are really hard to read. If there's a clear layout somewhere I might consider it.

I used to own an AA1164 and I loved the sound. So maybe...damn tubeswell you're making me change my mind.

[tubeswell]

Try this one:

http://www.el34world.com/charts/Schemat ... AA1164.pdf



FWIW most of the Fender schematics at the Hoffman website are good quality ones

http://www.el34world.com/charts/Diagrams.htm

[tribi9]

Yeah those schematics and layouts actually look pretty good. I'd have to get another transformer for the reverb tho'...

[tubeswell]

Well if you have a spare SE OT of about 5k - 8k lying around, you could build a BFPR with a pentode-driven 'verb with a 6BM8 (using the extra triode to help drive the pentode). You'd get nice harmonics in the 'verb that way.

[tribi9]

Well if you have a spare SE OT of about 5k - 8k lying around, you could build a BFPR with a pentode-driven 'verb with a 6BM8 (using the extra triode to help drive the pentode). You'd get nice harmonics in the 'verb that way.

Didn't you build a PR before? Is that what you did?

[tubeswell]

I've got one on the go at the moment (amongst a few other things), but its a conventional 12AT7 driver at this stage. Tho IMHO it would be easy enough to do a layout for a 6BM8 driver, and its only about ~700mA or so on the filament winding (as opposed to 300mA for a 12AT7)

(Edit - I quickly banged this idea together just now - see 1/2 schematic. I added a couple of extra Filter caps and dropper resistors because of the extra stages, but you probably could do it with just the one xtra RC filter supply network to the 6BM8 pentode/RT supply, altho IMHO the circuit could probably do with 2 such lots. The 6BM8 values are just pure guesswork, and it may need more attenuation between the triode and pentode - such as split load plate resistor or bigger voltage divider on the grid, esp if you want to get a nice clean input signal without crashing the pan, and you may even want to leave the cathodes unbypassed - depending on how much gain you have etc)

[Andy Le Blanc]

you can also turn the 6bm8 around. Use the pentode as a high gain stage,
use any bias method you prefer, dress the triode as a follower to a say
1uf poly and drive a tank that way too. dont have to use a driver tranny.

[tribi9]

That's a little too advanced for me. I'd prefer to stick to the stock circuit. However, once I get better I would like to try something like this on it using the socket for the tremolo.