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Just got a Federal Limiter AM- 864/U !!! Utility Plugins
Old 1st July 2006
  #1
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norman_nomad's Avatar
Just got a Federal Limiter AM- 864/U !!! (PICS!)

... and the amazing thing is that it's NEVER been used. I just opened it from its original packaging. It came wrapped in some strange foil/fabric material complete with stencil-style military print lettering. Cool!

Damn, this thing is massive!

So while I hook it up... tell me... .what am I going to love it on?

What do you find yourself using it on?

Any things to watch out for operationally?

Thanks!
Old 1st July 2006
  #2
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max cooper's Avatar
 

Damn... I hate you!!

Every studio should have a piece of gear that looks like that!

http://www.montagar.com/~patj/ftc.htm

Been wanting to find one for a while.
Old 2nd July 2006
  #3
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RedWallStudio's Avatar
 

Ha, I love mine... use it on bass, kick, snare, guitars... even on some vocals for an in your face distorted sound. I was looking at getting one of the big Gates or Collens comps.. and I saw this thing on E-bay for 400.00 bucks and I thought what the hell....man am I glad I did. The Output on it is insane. I had to get one of those Shure In-line -15db pads just to tame it down a bit. When I run a bass guitar through it, I get this thick rumbling distortion that feels like someone is punching you in the face. Instead of calling it a "limiting amplifier" that should called it a compressorator. Totally wicked... and It think it was built in like 1940?!?!?
Old 2nd July 2006
  #4
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Levi's Avatar
 

Actually, you will hate it tremendously!!! Please send it to me and I'll "dispose" of it properly for you... I'll even pay your shipping. heh
Old 2nd July 2006
  #5
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oops.. yeah thats what I meant to say... it sucks... worst great choice you can make. I'll take it off you for the scrap metal... how bout a hundy? Seriously, two of those in a rack with two distressors on top of it would look insanely funny.
Old 2nd July 2006
  #6
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dim light's Avatar
 

wow congrats!
Old 2nd July 2006
  #7
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pan60's Avatar
 

very cool !
Old 2nd July 2006
  #8
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adam_f's Avatar
I have two federals that came in a similar condition, plus a MAXSON Dept. Of Commerce.
Old 3rd July 2006
  #9
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norman_nomad's Avatar
OK guys, I have the Federal up and running but I don't think it's operating properly.

I'm a little confused by the rear barrier strip connections. There's 4 terminals: 2 are unmarked, 1 says "CT" and the other "G". I'm assuming "G" is for ground and "CT" is for the transformers "Center Tap". I'm attaching a picture of how my XLR cable is hooked up. Is this how you guys are doing it? I've also run a 600R resistor acorss what I think is the "+" and "-" to terminate the output. The blue and clear wire are my signal wires, the black wire is my ground. Does it look correct?

Here are my current issues:

1. The unit doesn't seem to compress lower frequencies; most everything below 400hz is not affected by the compressor.

2. The meter pegs all the way to the right on the gain reduction setting.

Do you think the tubes might have gone bad? The things been sitting in a sealed box for the last 50 years, so I'm wondering what might go bad over that time frame when not exposed to the elements.

How are you guys setting up your "Threshold" and "Current" controls?

Also, does anyone have a electronic manual they could send me? I'd like to be able to check some of the voltages, but I don't know what I'm looking for.

Thanks for any help!
Attached Thumbnails
Just got a Federal Limiter AM- 864/U !!!-federal-limiter-rear-pic.jpg  
Old 3rd July 2006
  #10
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RedWallStudio's Avatar
 

Quote:
Originally Posted by norman_nomad
OK guys, I have the Federal up and running but I don't think it's operating properly.

I'm a little confused by the rear barrier strip connections. There's 4 terminals: 2 are unmarked, 1 says "CT" and the other "G". I'm assuming "G" is for ground and "CT" is for the transformers "Center Tap". I'm attaching a picture of how my XLR cable is hooked up. Is this how you guys are doing it? I've also run a 600R resistor acorss what I think is the "+" and "-" to terminate the output. The blue and clear wire are my signal wires, the black wire is my ground. Does it look correct?

Here are my current issues:

1. The unit doesn't seem to compress lower frequencies; most everything below 400hz is not affected by the compressor.

2. The meter pegs all the way to the right on the gain reduction setting.

Do you think the tubes might have gone bad? The things been sitting in a sealed box for the last 50 years, so I'm wondering what might go bad over that time frame when not exposed to the elements.

How are you guys setting up your "Threshold" and "Current" controls?

Also, does anyone have a electronic manual they could send me? I'd like to be able to check some of the voltages, but I don't know what I'm looking for.

Thanks for any help!
I actually have an original manual with mine.. yikes (1954!) Here is how the manual reads for connecting a balanced connection.

"A balanced line is a two-conductor cable in which the pair of leads may, or may not, be twisted. It is covered by a metallic shield. To connect a balanced line to the INPUT or OUTPUT terminals, connect the center tap (marked CT) to the grounding post (marked G) on the amplifier. Connect the shielded twisted-pair leads to the terminals on either side of the center tap. Connect the shiled fo the cable used to the grounding post."

and for an unbalanced connection-
"An unbalanced line is almost always one of the following:
(1) A single conductor cable covered by a metallic shield.
(2) A two-conductor cable covered by a metallic shiled in which one of the two conductors is soldered or otherwise connected to the metallic shield for a ground connection.
(3) A two-conductor cable covered by a metallic shield in which the two conductors are soldered or otherwise connected together.
To connect an unbalanced line to the INPUT or OUTPUT terminals, connect one of the terminals on eitehr side of the center tap to the grounding post. Connect the grounded side of the line to the grounding post. Connect the high side of the line to the ungrounded terminal of the other side of the center tap."

Thats how the manual reads.. but this is how mine is connected, and pardon for the less than technical jargon... I didn't connect it, I just use it:

My tech put XLR pig tails on the INPUT and OUTPUT. On the output side I have RED wire attached to the post on the left of the CT and a BLACK wire on the right of the CT.. but NOTHING connected to ground. On the INPUT side, its the exact same, except he did connect the WHITE to the ground.

I don't know if this helps you much, but mine works fine. Good luck!
Old 3rd July 2006
  #11
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RedWallStudio's Avatar
 

p.s. I have an original printed manual.. not electronic, so if you can tell me exactly what you are looking for, I can retype it and send it to you for reference. Unfortunately, the entire manual is 55 pages of 12pt text (which is pretty crazy for a device that has two switches and one knob ) but let me know what you are looking for and I wouldn't remind typing out a section or two for ya.
Old 3rd July 2006
  #12
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norman_nomad's Avatar
Quote:
Originally Posted by RedWallStudio
p.s. I have an original printed manual.. not electronic, so if you can tell me exactly what you are looking for, I can retype it and send it to you for reference. Unfortunately, the entire manual is 55 pages of 12pt text (which is pretty crazy for a device that has two switches and one knob ) but let me know what you are looking for and I wouldn't remind typing out a section or two for ya.
Thanks a bunch RedWall!

So it appears I hooked it up correctly other than not bridging the connection between the transformer's center tap and the chasis ground.

What does the manual say about the "Limiter Threshold" and "Current Control". I'm not sure that the threshold on the Federal is acting much like a tradition threshold.

Also, are you padding your output? This thing has crazy gain!

If anyone out there has an electronic manual it would be much appreciated!

Old 4th July 2006
  #13
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max cooper's Avatar
 

Quote:
Originally Posted by RedWallStudio
I actually have an original manual with mine.. yikes (1954!) Here is how the manual reads for connecting a balanced connection.
To quote an old K-Mart commercial:

"Is this place great, or what!"
Old 4th July 2006
  #14
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RedWallStudio's Avatar
 

Quote:
Originally Posted by norman_nomad
Thanks a bunch RedWall!

So it appears I hooked it up correctly other than not bridging the connection between the transformer's center tap and the chasis ground.

What does the manual say about the "Limiter Threshold" and "Current Control". I'm not sure that the threshold on the Federal is acting much like a tradition threshold.

Also, are you padding your output? This thing has crazy gain!

If anyone out there has an electronic manual it would be much appreciated!


Yeah, it looks like you were pretty close on the connections... hope that works and nothing is wrong with the unit itself.

I purchased one of those Shure In-line pads... I forget if its -10db or -15db, but I haven't used it yet. I have been using the Federal for Bass Guitar, and the distortion I am getting is great.... If I were using it for more traditional type of stuff, Id probably be padding it 100% of the time.

As far as LIMITER THRESHOLD goes, this manual reads like stereo instructions.
I'll quote the only thing I could find in the manual that pertains to it... hopefully it will help shed some light.

"The LIMITER THRESHOLD control determines the degree of limiting which will take palce for any predetermined increase of signal level. This control is preset so that a 10-db increase in the input signal level would produce a 1-db increase in the signal output level of the amplifier. If this control is rotated counterclockwise (toward the cathode), the limiting action of the amplifier will be reduced, and the output of the amplifier will increase by more than 1 db for a 10-db increase in input signal. If the control is advanced too far in a clockwise direction (toward capacitor C5), the output level of the amplifier actually will decrease with an increase of input signal level."


This manual is hilarious. If you bought this new, the Comp would be: 1) surrounded by 6 cardboard pads - which would be inside of a cardboard carton - which would be inside of a moisture proof barrier - which would be inside of another cardboard carton - which would be inside yet another waterproof barrier - which would be inside of wooden crate.

And inside the very front cover of the manual reads: WARNING - HIGH VOLTAGE is used in the operation of this equipment. DEATH ON CONTACT may result if operating personnel fail to observe safety precautions. stike
Old 4th July 2006
  #15
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ramjet's Avatar
 

hi

congrats on the score. any chance of pics inside outside and any crevise you can photograph would be way cool

cheers ramjet
Old 4th July 2006
  #16
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norman_nomad's Avatar
Quote:
Originally Posted by RedWallStudio
Yeah, it looks like you were pretty close on the connections... hope that works and nothing is wrong with the unit itself.

I purchased one of those Shure In-line pads... I forget if its -10db or -15db, but I haven't used it yet. I have been using the Federal for Bass Guitar, and the distortion I am getting is great.... If I were using it for more traditional type of stuff, Id probably be padding it 100% of the time.
Gotcha... I think I'm going to need to get a pad for the output of my unit... it's clipping my converters... this might have something to do with the fact that the low end just isn't getting compressed.

Quote:
Originally Posted by RedWallStudio
As far as LIMITER THRESHOLD goes, this manual reads like stereo instructions.
I'll quote the only thing I could find in the manual that pertains to it... hopefully it will help shed some light.

"The LIMITER THRESHOLD control determines the degree of limiting which will take palce for any predetermined increase of signal level. This control is preset so that a 10-db increase in the input signal level would produce a 1-db increase in the signal output level of the amplifier. If this control is rotated counterclockwise (toward the cathode), the limiting action of the amplifier will be reduced, and the output of the amplifier will increase by more than 1 db for a 10-db increase in input signal. If the control is advanced too far in a clockwise direction (toward capacitor C5), the output level of the amplifier actually will decrease with an increase of input signal level."
Hmmm... this reads more like a control for a RATIO setting rather than a threshold. Stock the unit is set at 10:1 and then can be set more gently (CCW) or all the way into negative ratios (CW).

Quote:
Originally Posted by RedWallStudio
This manual is hilarious. If you bought this new, the Comp would be: 1) surrounded by 6 cardboard pads - which would be inside of a cardboard carton - which would be inside of a moisture proof barrier - which would be inside of another cardboard carton - which would be inside yet another waterproof barrier - which would be inside of wooden crate.

And inside the very front cover of the manual reads: WARNING - HIGH VOLTAGE is used in the operation of this equipment. DEATH ON CONTACT may result if operating personnel fail to observe safety precautions. stike

Haha.. Yep, this is a mans compressor alright!
Old 4th July 2006
  #17
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If you want to e-mail me or post me your address, I can get a copy of the manual made at the Kinkos down the street and send it to ya in the mail... it'll only run me a couple of bucks, but it sounds like it will be worth it to ya, so its not a problem at all.
Old 4th July 2006
  #18
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norman_nomad's Avatar
Quote:
Originally Posted by RedWallStudio
If you want to e-mail me or post me your address, I can get a copy of the manual made at the Kinkos down the street and send it to ya in the mail... it'll only run me a couple of bucks, but it sounds like it will be worth it to ya, so its not a problem at all.
Wow. That would be fantastic. I can send you money via paypal to make up for the expense/bother.

I really appreciate the gesture. I want to get this baby up and running!

PM sent with address. heh
Old 4th July 2006
  #19
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norman_nomad's Avatar
Quote:
Originally Posted by ramjet
hi

congrats on the score. any chance of pics inside outside and any crevise you can photograph would be way cool

cheers ramjet
As requested!





Attached Thumbnails
Just got a Federal Limiter AM- 864/U !!!-federal-front.jpg   Just got a Federal Limiter AM- 864/U !!!-federal-meter.jpg   Just got a Federal Limiter AM- 864/U !!!-federal-rear.jpg   Just got a Federal Limiter AM- 864/U !!!-federal-serial.jpg   Just got a Federal Limiter AM- 864/U !!!-federal-tube.jpg  

Old 4th July 2006
  #20
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norman_nomad's Avatar
And some pictures of the packaging...


Attached Thumbnails
Just got a Federal Limiter AM- 864/U !!!-federal-arimex-desiccant.jpg   Just got a Federal Limiter AM- 864/U !!!-federal-bag.jpg  
Old 4th July 2006
  #21
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peeceebee's Avatar
 

Wow!
(Change the filter caps...)
Old 4th July 2006
  #22
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norman_nomad's Avatar
Quote:
Originally Posted by peeceebee
Wow!
(Change the filter caps...)
Thanks Pete,

That's the next step. Could bad filter caps cause the unit not to compress the low end?

I did some quick voltage tests on the tubes and I'm getting double what I'm supposed to on some pins. On V1/V2 (input tubes) pin 8 is reading 350v.

What do you think this means?

Damon
Old 4th July 2006
  #23
Lives for gear
Quote:
Originally Posted by RedWallStudio
If you want to e-mail me or post me your address, I can get a copy of the manual made at the Kinkos down the street and send it to ya in the mail... it'll only run me a couple of bucks, but it sounds like it will be worth it to ya, so its not a problem at all.
Save yourselves some time and money and just have Kinkos scan it with their automatic document feeder / scanner and .pdf it to him (e-mail).

That way, you'll also have a backup electronic copy...

Man...a NOS 1940s limiter. I gotta raid some US Army storage locker. My Dad was in the Dutch signal corps back in the 50s. I wonder what gems he could have lifted off of those bases for me.
Old 4th July 2006
  #24
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dude that is a seriously great find

love the mint condition that is just the best

cheers ramjet
Old 4th July 2006
  #25
Led
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eyyyyy......nice condition unit that one....I've got two of em..one is serial 282.
I like the bit in the manual that tells you how to destroy it so the enemy doesn't get hold of it. Who's got the [email protected]!
I'm a bit suss on the radio shack type pad...I've found those can actually mess with the low frequency response. I run mine on group outputs on my console and just control the levels with faders. The easy way to think of the controls is that the limiter threshold is actually the ratio, and the current control is the actual threshold. If you are behind the unit looking at the controls, the one marked limiter threshold increases the compression ratio as you turn it clockwise. Full counter clockwise is the lowest ratio. The control marked current sets the threshold higher clockwise and lower counter clockwise. To get the absolute minimal compression turn the "limiter threshold" control full counter clockwise and the "current" control full clockwise.
I've moved the pots for both to the front of mine. I can patch it if I want to restore them, but it is a lot easier having them on the front. I put chickenhead knobs on them. I'll put a pic up tomorrow. I mainly use mine in parallel, but I do love putting them on the insert of a distorted guitar track.
Man hang on to that original bag too. Nice score. Damn nice unit. Well done soldier.
Old 4th July 2006
  #26
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That is a thing of beauty!

Here's a thread from elsewhere that might be handy for you: http://www.prodigy-pro.com/forum/viewtopic.php?t=11681

I'll be keeping my eyes peeled for one of these now.

Let us know how it all turns out.

Lee
Old 4th July 2006
  #27
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RedWallStudio's Avatar
 

Holy crap Nomad, that thing is in total "time capsule" condition. What a score! Mine is a little beat up on the face plate, so I was considering repainting the front... I think seeing yours has given me inspiration to do that now.

And thanks for the Kinkos>auto doc feeder>pdf idea, that will work great... I'll post it tomorrow in the evening.stike
Old 4th July 2006
  #28
C/G
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Where did you find that thing? You don't have a time machine do you?
Old 4th July 2006
  #29
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Quote:
Originally Posted by RedWallStudio
If you want to e-mail me or post me your address, I can get a copy of the manual made at the Kinkos down the street and send it to ya in the mail... it'll only run me a couple of bucks, but it sounds like it will be worth it to ya, so its not a problem at all.
Hey....you can find some really Great people here at GearSlutz..!...
Old 4th July 2006
  #30
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norman_nomad's Avatar
Ok. I just put an order in for some replacement filter caps and signal caps. Hopefully this will resolve the issue. I'll only replace what I need to. I'm going to try and keep the unit as stock as possible.

Thanks for all the info so far; it's very helpful. Once I get the beast up and running I'll try to post some sound clips.

I'll keep you guys updated!
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