Fairchild 670 DIY In Progress

[marc11657]

Hi mdainsd,

Good to see someone else is also embarking on this huge task. How are you going to get around the cap problem? I'm thinking of finding a dead one that looks as close to the original as possible and stuffing it, as CJ is doing.

I'm also at the designing stage of the rack chassis but I'm missing a few crucial components before I can get exact measurements for the size and placement of the punches. I'm writing everything down and doing all the work on the PC so that I can easily make it available to anyone who is also interested in making a FC. Once I get my CAD done I think I'll upload it to the tech docs for anyone else to have their FC rack made up.

It is an 8U piece of equipment, 14" tall for all practical purposes. I too intend on building a period correct re-creation. Thats one reason I joined here. There are some very talented people here, this thread being a great example. Im looking forward to seeing this build completed.

Im taking a slow approach. First collecting every piece of documentation I can fine along with photographs.

I have started hunting NOS original parts, A real task but I also enjoy the hunt. i dont plan on starting any construction until the parts pile reaches critical mass. The tubes will be the "easiest" to acquire, so I'll hold off on them. Unfortunately some things like vintage caps are probably a non starter as even NOS ones from the 50's have deteriorated. So some compromises will have to made. The pile is growing pretty well.

Im in process of laying the chassis out in the sheet metal suite of SolidWorks. If it gets the green light its just an email to the sheet metal shop down the street and pick the pieces up a week later.

Im trying to refrain from asking questions until I really get stumped, which will happen.

Anyrate, back to this thread....Hows the progress?

Inquiring minds want to know.

 

[mdainsd]

We probably shouldnt be hijacking this thread. Start a new one about planned builds or somesuch and we can carry on and maybe get some suggestions, just sayin

 

[skal1]

Hi Cj,

what bias tx and choke did you end up using for the line amp .

skal

 

[CJ]

that chassis is still waiting to be finished, 

there is 17-6618 penciled in on the print for the bias xfmr, could be a triad or stancor number,

will probably wind a choke and adjust DCR til it comes out right,

just need to get some 7 pin tube sockets for the mil version 6BA6 tubes, ripped out the 6386 sockets and components, hopefully this will get done this winter,

 

[Rob Flinn]

hopefully this will get done this winter,

Oddly I've been saying that about my build for about the last 10 years ....

 

[jackies]

C'mon CJ!

 

[radardoug]

Yeah cmon CJ! There are 24 hours in the day, you must be spending too many of them sleeping or drinking or eating.
Us couch potatoes are dying to see this mother going, cause we are too lazy to build one.

 

[CJ]

ok, alright, we will order the 7 pin sockets, and get this thing going, and the filter caps for these V-72 amps for the poor person that we owe amends to, have to send them some Reddi OPT's as interest,

 

[radardoug]

CJ, has there been any progress on this?

 

[kambo]

it was a winter project, but there is no winter in CA ???

 

[Whoops]

Hi CJ dont know if this helps, But I have a picture from the internals of a Fairchild unit that belongs to a studio I worked.

 

[Whoops]

I uploaded the 670 instructions manual and The Technical Bulletin to the technical documents section here, but can't see my posts in the end of the page.

Can please someone confirm if they have the same problem?

http://groupdiy.com/index.php?topic=45705.0