RCA BA-43 / RCA BA-45 AGC tips mods schematics
« on: March 03, 2005, 02:36:50 AM »
Hi everyone (my first post..newbie) GREAT SITE!!! DIY la2a gonna happen! Now to the business at hand
 I have 4 channels of RCA agc. the BA-45/BA-43 program amp and compressor/expander combination.
i need info on the availability/substitution for the opto units
Raytheon Raysistor ck2013.
Also schematics or manual help wouild be great too.
thanks
ToobieSnack
PS any help offered on my other gear listed  below (signature area) will be great too.
I need help with  RCA BA-43/ BA-45. RCA BA-25a, RCA BC3 mic pre's, Gates Level Devil, Federal AM-864u, DIY la2a stuff, Altec 436b


soundguy

RCA BA-43 / RCA BA-45 AGC tips mods schematics
« Reply #1 on: March 03, 2005, 02:47:36 AM »
toobiesnack is a fantastic screen name.

I hope the guy that winds up helping you is named shaggy.

dave

chips are good with dip...

ToobieSnacks for everyone
« Reply #2 on: March 03, 2005, 02:55:12 AM »
thanks for your compliment on my screen name.
I put a lot of thought into hehe
toobie newbie doooo.....
I need help with  RCA BA-43/ BA-45. RCA BA-25a, RCA BC3 mic pre's, Gates Level Devil, Federal AM-864u, DIY la2a stuff, Altec 436b

gary o

RCA BA-43 / RCA BA-45 AGC tips mods schematics
« Reply #3 on: March 03, 2005, 06:21:47 AM »
Hi Toobie... Im currently DIYing a Federal AM864/U if I can be any help to you, I still have lots to learn tho, theres lots of folk on here who really know there stuff that im sure will help you out, I also DIYed a LA2A theres loads of great reading about those too.

Cheers ....Gary O.

thanks for your responses
« Reply #4 on: March 03, 2005, 12:18:33 PM »
My main priority is these rca units.
However...
I have a mint Federal AM864-U. passes audio but don't compress...hmmm
I'll start a new post for that to help keep the META threads organized. But if I can help I will.
Good luck
ToobieSnack
I need help with  RCA BA-43/ BA-45. RCA BA-25a, RCA BC3 mic pre's, Gates Level Devil, Federal AM-864u, DIY la2a stuff, Altec 436b

gyraf

RCA BA-43 / RCA BA-45 AGC tips mods schematics
« Reply #5 on: March 03, 2005, 02:20:52 PM »
The Raysistor, I believe, is a combination of a LDR and a lamp, not a LED. I don't see why you couldn't take apart the Raysistor and replace the lamp.



Jakob E.
..note to self: don't let Harman run your company..

Graf thanks for your reply
« Reply #6 on: March 03, 2005, 04:10:45 PM »
yeah i knew the configuration and I can get a NOS replacement but the actual model number is not identical. (from organsupply CK2083)
original part is ck2013
Do you think the LDR's in my units are OK?
Can i simple measure resistanse and if there is any then the LDR is fine?
Will a bad LDR read like an open circuit?
I was reading info on the t4 mod here on youir site and that there was a testing method for those.
Can I use the same method to determine the difference (if any ) between the 2 units?
I would be interested to know the difference between the 2 models of raysistor opto's.
do you think it is basically the same but with minor improvements?
Maybe they were packaged specially for RCA?
Hence the diff model number. (not likely huh?)
Can anyone help with specs from a catalogue or manual etc?

I am hopeful that this replace the light bulb fix will be the answer.
BTW is there any certain bulb I should use?
Looks like a dumass lil xmas light right?

Well, that's all I can think of right now
thanks for all your help.
and remember "Toobie Snacks are Gooood" hehe
ToobieSnack
I need help with  RCA BA-43/ BA-45. RCA BA-25a, RCA BC3 mic pre's, Gates Level Devil, Federal AM-864u, DIY la2a stuff, Altec 436b

adrianh

RCA BA-43 / RCA BA-45 AGC tips mods schematics
« Reply #7 on: March 03, 2005, 05:44:08 PM »
I bet your light bulb is open!

Someone please second me on that.

re: bulb and LDR
« Reply #8 on: March 03, 2005, 05:57:54 PM »
yeah the bulb in one is smashed to hell.
But.... I got a good look inside without haveing to make that decision to tear it apart. hehe
I have 4 channels and some of them might be fine.
one is definitely smashed.
I can figure the open circuit crap on the bulb out fine.
***if not kick me outta here hehe (kidding)
Like the chik who asked
"does she have to add heaters to her tubes"
 LOLOLOLOLOLOLOL
Damn funny!! but nobody is beyond redemption.  hehe
 Anyway thanks for your post (funny as it might have been... I laughed)
At least I hope you were kidding about the light bulb.
Who knows I might not have known that.
ToobieSnack

PS Always remember "toobie snacks are gooood"
I need help with  RCA BA-43/ BA-45. RCA BA-25a, RCA BC3 mic pre's, Gates Level Devil, Federal AM-864u, DIY la2a stuff, Altec 436b

PRR

RCA BA-43 / RCA BA-45 AGC tips mods schematics
« Reply #9 on: March 03, 2005, 11:07:04 PM »
> Do you think the LDR's in my units are OK? Can i simple measure resistanse and if there is any then the LDR is fine? Will a bad LDR read like an open circuit?

Put ohm meter on LDR.

In room light it will read maybe 1K-10K. With bright light, probably under 1K. In the dark, it should slowly rise to over 1 Meg. It may have to be VERY dark to hit 1 Meg: a cardboard box was not enough, I had to have 3 layers of heavy black paint.

But that is all there is. High resistance when dark, low resistance when light.

The exact amount of resistance at any given light level, and the speed of response, varies a LOT between different models of LDR (and even for different LRDs of the same model and batch). So I hope yours are good: finding an exact replacement may not be possible. Using those organ supply modules may not work the same: Raytheon has not made LDRs in decades, nobody makes them the same, so if they are new they will be non-Raytheon and something-different. In an organ they probably just give a medium volume change at fairly low speed (tremulo) so the exact value isn't too critical. But in an opto limiter the value-change may be wide and the speed of response is critical to the attack and release characteristics.

> Looks like a dumass lil xmas light right?

Yeah, that's what it looks like. But again: dumass bulbs come in various voltages and currents. While this box never takes the bulb to full rated voltage, the bulb voltage and current controls the relation of signal to depth of limiting. Also in the same rating the filament may be thin and quick to light or rugged and slow to light, affecting your attack release timing.


 

Related Topics

  Subject / Started by Replies Last post
18 Replies
7045 Views
Last post December 05, 2006, 12:59:35 PM
by gary o
1 Replies
1527 Views
Last post April 23, 2012, 07:52:02 AM
by jensenmann
20 Replies
4399 Views
Last post October 02, 2012, 05:53:05 AM
by Majestic12
7 Replies
1016 Views
Last post December 13, 2019, 09:09:50 AM
by rackmonkey