Motorola Chassis

[Phil_S]

This is a recent eBait score. One never knows. It came with 5 tubes:
Two EL84 marked Made in Gt. Britain and the telltale Mullard seam on top - nearly wet my pants over this. (Not really.)
One 12AX7 made in Japan, two top seems, guessing it's a Japanese Mullard or Matsushita
One 5U4 looks to be RCA, not sure.
Two 6V6GTA, stop sign etched on top, RCA?
Three OT's, one multitap PP for the 6V6's and two SE for the EL84's, all with Motorola numbers on the top band.
One sizable PT, we know it had the juice for this tube compliment, so I'd guess it's good for maybe 200mA, haven't put a pencil to paper.
Nice looking sockets. Lots of free real estate in the chassis.
I'm pumped and just had to tell someone! $51 shipped. If the tubes are good, I think it is safe to say I made out OK.

[Andy Le Blanc]

wet to the knee's

its just great to stubble over NOS in fair shape

get some V and I measurements, plate voltage and bias on the PS
and see what the turns ratio are for the OPT

Nice score

[Bob S]

He shoots - he scores!
Nice one. Sometimes we win one.

[Cliff Schecht]

Some older chassis are coated in something that is supposed to be toxic. I forget what it is and can't find it in Google but I don't think this is what you have. What I'm talking about is that yellowish crap that chips off. Maybe somebody else can swoop in and make me look like less of an idiot.

[David Root]

Nice score! Those 6V6GT look like '52 Tungsol blackplates, if NOS NIB, $120.00. Are you sure they're GTAs? If so, '62, only NOS NIB $95.00. Sorry!

[Phil_S]

Oh gosh no, tubes are not NOS, just supposed to be good used, no boxes, all rebranded Motorola. Still, those Mullards alone must be worth at least $40 for the pair.

David, The 6V6's have:
6V6
GTA
in a stop sign etching on the top of the tube. Do you want a photo? Tung Sol, wow!

Andy, I'd love to get turns on the OT's. I have a hole in my roof 2' x 10' from Irene. A tree came down on the house. I've got my hands full with that and don't know when I'll get to it. This thing was purchased about a week ago. What timing, huh?

It will be interesting to see what the PT does, too. I'm guessing unloaded HT secondary will be in the mid 200's, respectable enough to work with.

I am not planning on saving the circuit. The can cap was dented and loose. I already clipped it.

There is no fuse, no switch. I will have to make it safe before I do anything.

Cliff, this appears to be a fairly standard tin coated chassis from that era. I don't think it is copper. Copper is reddish. I am having a hard time thinking it's toxic, but would like to know more. I'll harvest and discard the chassis if there's any doubt. Even with a discard, I really did OK on this one.

Thanks for celebrating with me on this one. I can use some cheering up after that tree came through my roof. I think we are going to be sleeping in the living room for 3 months. We have to peel about 1/3 of the roof, and gut two bedrooms just to inspect the damage. We can see at least 8 cracked rafters where the ceiling fell down. It was a 100' oak. I looked up the density and I am estimating the tree was 25-30,000 pounds. It is darn good the house is mostly brick.

[Phil_S]

Nice score! Those 6V6GT look like '52 Tungsol blackplates, if NOS NIB, $120.00. Are you sure they're GTAs? If so, '62, only NOS NIB $95.00. Sorry!

Transformer codes are 9496239, 9496240, 9496241. It is a safe bet these tubes are from 1962 also. Thanks for the ID. I guess, these used ones could have some decent value. I don't have a fixed bias 6V6 amp to plug them into to see what the current draw is. I will probably rig something up after a while, just to see.

949 = Burr Brown whoever they are/were.

[Cliff Schecht]

Burr-Brown makes (made) high performance IC's in the 70's and 80's. Back in their glory years they made some of the best performing op-amps and instrumentation amplifiers that one could buy as well as other high performance integrated circuits. They are now owned by TI but parts of Burr-Brown are still around, including the old facility originating in Tucson, Arizona. Most of the high performance audio parts have a Burr-Brown stamp on the datasheet. In other words, it's a mark of quality .

And as far as the toxic coating I was referring to, what I was thinking of is the cadmium coating that was used on some chassis. It helps with corrosion resistance and solderability on steel chassis. As the cadmium ages it turns into a yellowish-white powder that is considered toxic. I don't think that's what you have there, what you have just looks painted, but if there's a powdery white substance in there, don't start snorting it!

[Phil_S]

Thanks, Cliff. I don't see any powder. I think I'm in the clear. Thanks for the commentary on Burr Brown, too. Interesting.
Phil