Vintage McCurdy broadcast desk

Looking for Radio equipment? Got stuff for sale or trade maybe even giveaway .. . Need help with a project??

Re: Vintage McCurdy broadcast desk

Postby Eldon-Mr.CFAY » Sun Mar 31, 2013 2:07 am

Greetings,
Thanks very much Jon for posting Scott's photos and even more interesting looks at McCurdy Boards and the studios! Gosh this topic is really informative. Many thanks Mike Cleaver too for all your suggestions to Gord and us about restoring the McCurdy Board, I have read it all and it looks very complete! Thats interesting now that we have two Radio West Members with McCurdy Consoles. Much of what Mike has said I agree with Gord on checking out the McCurdy and restoring it! Finding any missing parts might be a problem but as Mike said checking EBAY online could help. I have a couple other suggestions too which I will email you. Anyway just thought I would thank everyone for posting all the information. I like McCurdy Boards a lot and hope to find one myself in the near future. By the way the other day I just found a 1980 Price List for McCurdy Broadcast Carts and Tape Machines, a lot of detail to it. I know I have some spec. sheets for McCurdy Boards out in Langley too going back to 1979 or so. When I get a chance here in Ontario I am going to give them a phone call and see what information they currently have. I suppose I could check them online too. Anyway best of luck to getting everything operational Gord and Scott. Have a Great Easter Weekend!

73s Eldon
Bye . . Mr. CFAY "Frequently On The Frequency"
The CFAY Website: http://cfayradio.wordpress.com
CFAY Radio: http://tinyurl.com/l9qqmh
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Sun Mar 31, 2013 3:52 am

Eldon, the knob fairy came out form her lair long enough to cough up a couple of Bakelite knobs and a pot that will go into CH #1 and complete all eight channels. I can't believe my good fortune, and assumed I would have to search for years for these, if I ever found any at all. I've had the thing a week and already a kind and generous member of the broadcast community checked with a source and lo and behold I have two knobs and a pot on the way. I'm going to make a list of the parts I'm still missing (not a long lits at all, I assure you) towards my attempt, at some point down the road, to get this up and running,

Scott S, thanks for the pics (and thank you, Jon, for putting them up). Your rooms look fabulous, and good for you, for saving broadcast history and doing something with it. My setup, once we decide where we're going to wind up after the empty-nest thing happens, won't be quite so elaborate. But there will be plenty of hints as to the genesis and progress of both my writing and broadcast career, and the McCurdy SS4370 is going to be a big part of that.

The rotary Mac board you have is a 10 channel I see, and this looks exactly like the board I opped in Lindsay when I first started in the biz. I was hoping for a 10, but the 8 will do and besides, the 8 is a full stereo board, so that's a bonus. Mike Cleaver and several others have made this point already, that while McCurdy Industries no longer manufactures audio consoles they apparently keep master documents on file and will provide copies of manuals and schems for a fee.

Find them here:

http://www.mcradio.com/

Then just log down the model and serial number of the two Mc boards you have (found on the back...in the case of the 10-channel rotary board the info ID plate is at the back, right corner...). I have a full set for the board I have, but some of the images are faded so I'm going to see if I can get a better copy from McCurdy.

The slider board appears to be in pristine condition, whereas the rotary board looks like it needs a fair bit of cosmetic work....which may mean dismantling it and restoring the case first, before putting it all back together. I'm still debating whether I should do a full cosmetic rehab to mine, or leave it as-is for historical purposes. It was a one-owner and the history behind it is kind of cool.

I'm not an engineer so I have no idea what I'm in for, but it's still cool to finally find the rotary version, of the era we both have. I've fancied one of these for decades, and have been hunting high and low for years to find one. It's been a long journey. Would have been easier if it had just dropped into my lap, but that particular Karma eluded me.

You have some nice stuff there, Scott and a cool set-up. Congrats.

Gordo
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Re: Vintage McCurdy broadcast desk

Postby scott s. » Sun Mar 31, 2013 7:55 am

Thanks for the comments. It's also nice to have proper rooms within the basement to do a proper set up. The Control Room was either a studio for the previous owners pro tools setup, or a control room for the bigger space he can record in. Not sure, but it's split accordingly with me and was the major reason my wife and I bought the home.

It's about a year and a half since we moved in, I did the complete tear down and reassemble of both studios myself. Production was priority as we have a weekly show for a few LPFM's coming out of it....then control. The move overall went well, but just a LOT of work.

I can't totally take credit for all the saving, a friend, Ron Bickle, who ops manager at CFTA in Amherst, NS, let me "shop" in his basement for a few things. His wife was very happy at that....LOL! He also brokered the Mccurdy 8820 sale and also gave me a tip on someone selling a 1940s vintage RCA 70D Transcription Turntable which I obtained last year. It's built like a tank and runs great! I have more then a few transcriptions to play on it...:)

The CH 12 turntables work great in the control room.....spent an hour spinning 45s on them without any problems on good friday..nice and tight. I confess, I don't know how anyone could do it for a 4 hour shift daily, as it can be very exhausting.

I jokingly call my basement SPARC east. LOL!

Scott S.
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Re: Vintage McCurdy broadcast desk

Postby scott s. » Sun Mar 31, 2013 11:33 am

I might add I'll probably contact Mccurdy about the 8820. I can hear noise when I turn up the pots even hiss from the masters and headphone jacks, which is a good thing, but can't feed audio into it from the existing cables that are still soldered to the terminal strip. completely dead. all pots seem to be be working through if the noise is any indication, but it's a bit of a road block at this point. meters even jump when I power up. I may have some of the modules in the wrong place perhaps. It came in pieces, and could easily have been put together wrong, but it was a best guess.
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Sun Mar 31, 2013 12:26 pm

You're more brave then me, Scott. I'm not going to take power to the SS4370 until I have everything recapped, scoped out and a herd of technician friends I have here in town give me the okay. I'm thinking summer at best - and that's only if I can persuade a fine fellow from Lindsay who has experience with these things if he wouldn't mind driving over and having a look at it...

I'm quite timid when it comes to electrical stuff.

You said you do radio programming out to LPFMs? Is there a link where we can find you?

g
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Re: Vintage McCurdy broadcast desk

Postby scott s. » Sun Mar 31, 2013 3:56 pm

I've played around electronics since I was a kid, with a few mistakes here and there. If you power it up, prepare to pull the plug if you need smoke....sometimes it's the only way to resolve the issue, as troubleshooting sometimes can pull your head out. I'm also technically inclined. I have to be. Manuals are a wonderful thing. I'm far from a technician, but I'm not too timid either. It's a matter of comfort level. the 4370 doesn't have anything for indication of where you connect a power cord, so i'm sitting on it for now (and not even a plate to tell you what model it is) whereas the 8820 is pretty common sense for power, 4 modules in a rack, connect the big cable from the console to the rack and watch if anything blows fuses or anything else. I did have a fault trip on one module, but after some troubleshooting, determined it was a fader module being the issue, and seems to be working fine. Just have to get around the problem previous mentioned, and I might pass audio on it.

As for the show, the website is my website link on this forum. It's totally silly and not really commerical radio oriented, but I have fun with it. Even a few LPFM's in BC....
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Sun Mar 31, 2013 6:20 pm

Well gents, the more I dig into this old girl the more it's beginning to make a little bit of sense to this untrained eye of mine. Having the schematics helps, and I've poured through them...and with every pour-through, even though most of it is Latin to me, a little bit is coming into focus.

Even though it doesn't have a full complement of modules, there are enough there - as Mike suggested - to get by with, and more on that in a minute.

What I am missing is a small transformer identified as being in position T 11 and is identified as a transformer that feeds the cue system. I'm also missing something called an AT 263A, which goes in at position A 19 and is identified as a monitor amplifier. So what this suggests to me is that I won't have a working cue system, or talkback (probably, but I don't need that anyway for the moment), or what I would need to drive a monitor. I just wonder if, without those two pieces, there will not be anything to drive the headphones.

I'm also missing what appears to be two, out of four power supplies. Mike Cleaver thought, based on memory, there was one or maybe two power supplies...either both to drive the thing or one serving as a redundant. There is a massive transformer, identified as going into position T 28, that is said to drive all the power supplies. But that said, there appears to be four power supplies, or which I only have two.

Here's what the book says: "There are three PS 878 48 volt regulators for program, monitor and cue amps." These are identified as PS 2, PS 3 and PS 4. I'm hopeful that the order in which they were described...ie, 'program,' 'monitor' and 'cue' is in order and therefore corresponds with the numbers...ie, PS 2 would be 'program,' PS 3 would be 'monitor' and PS 4 would be 'cue.' That would make sense, wouldn't it?

The fourth power supply is actually the first one that is identified as PS 1 and is described as PS 877, a 36-volt regulator for input and booster amps.

The book also says this" "A separate 24-volt dc unregulated supply is provided for dc control. All supplies are fed from transformer T 28."

What I am missing are the supplies that sit at position 1 and 2. I have 3 and 4. Thus, I need a PS 878 and a PS 877. I suppose, since 2, 3 and 4 are all PS 878s, I could harvest, say, #4 which I assume drives the cue circuit (I'm missing the transformer anyway) and move that one into PS 2, which I would assume drives the PGM circuit, which is what I would need, bare bones, to get the board operational. That just leaves PS 1, which is the PS 877...which appears to be an important one....

As for modules, as I said at the top most of them are there, and thanks to the schematics I can figure out what slots feed what. I can also look at the front of the board and judging by what the tags / labels say for the specific channels, I can tell what that channel was used for.

Channels 1 - 3 on this one were wired for carts, tape decks etc. And the slots contain MT 244A modules, which are described as being appropriate for matching high level inputs. CH 4 is the CR mic channel, and it had a lone AT 240 sitting in the 'stereo right' slot with nothing in the left. I don't know what an AT 240 is, but going through the manual the AT 240"A" is a pre-amp designed for low-level inputs. There are other areas where they have 240As for mic inputs, and there are various references throughout the manual to this affect as well, so I've come to the conclusion that the 240A is the appropriate module for microphones.

They also had CH 7 on the front of the board ID'd as a mic channel, and lo and behold there was a lone AT 240A in the 'stereo right' slot (nothing in the left, or the top row of the two-row rack).They also had an AT 240A sitting in stereo left of A13, which appears to be the stereo record bus. Nothing in the right. I don't know if there was a reason why the right-hand side was empty, but again....the bottom rack, which is a bit more difficult to service, was completely full of modules while any of the missing ones were from the top rack - which is more accessible - so my guess is, the modules were harvested for the other, twin to this board they had, once this board was decommissioned.

Anyway, I don't anticipate using the record bus of the board for anything....unless, of course, I start up an internet radio station someday and therefore cannot interrupt the program to record a weather forecast or something on record bus. So...just for fun, I removed the lone AT 240A from the record bus (left) and also removed the lone AT 240A from the right side of CH 7 - which was identified on the board face as a mic channel. I then swapped out the lone AT 240 from the R (bottom tray) of CH 4 and I now have to AT 240A modules in CH4, which is wired as the main CR mic.

Makes sense to me. And here's another reason why I think the AT 240A is the preamp, and thus appropriate for microphones. In the A10 slot, which is identified in the schematic as being the PGM BOOST, they have two AT 240As sitting there. Beside them, at A9 which is identified as BUS IN, they've got two MT 244A modules sitting there.

Thus, it seems that if and when the day comes that I get this puppy up and running, after it's been recapped and given the once-over by some kind of professional, I will at least have a working mic channel with two AT 240A modules left and right in CH 4.

Here's the thing. Remember when I said CH 4 originally had a AT 240 (no "A") sitting in the Right slot (bottom tray), with nothing above it? Well, when I pulled the module out and looked at it, someone had written this on the side of it: "Modified for phase reversal (underlined), June '76." Does that mean there is a problem with phase reversal in CH 4 and they had to modify this particular module to compensate for it? Or was there a problem with the module itself, so they had to modify the module just so the module would play nice?

And because there was an empty slot above it, I don't know what was in there....whether it was another AT 240 or an AT 240 A. There are no other AT 240 modules in the console, just the one. The remainder are AT 240 A, MT 244 A and three AT 242 A modules sitting in PGM LEFT and PGM RIGHT, and what appears to be RECORD BUS mono at A13.

Anyway, that's my story for tonight. Looks like I'm looking for the four pieces noted above....the AT 263A that sits at position A 19, the small transformer that sits at position T 11, and the PS 877 power supply that sits at PS 1, and the PS 878 power supply that sits at position PS 2.

Have a great evening....

Gordo
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Sun Mar 31, 2013 6:25 pm

Would anyone have any of the small, brushed aluminum (round) channel keys for a McCurdy SS4370? I'm missing two...

Just two...

Gordo
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Sun Mar 31, 2013 7:14 pm

And one more thing, the part that sits at T 11 is identified as a McCurdy 2001 Transformer, audio input, matching (with the transformer at position T 21)
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Re: Vintage McCurdy broadcast desk

Postby Mike Cleaver » Sun Mar 31, 2013 8:21 pm

On stereo boards, the mics always were left only.
The only time two mics were used in one position in stereo was at the very beginning of stereo FM but the practice proved to be too distracting for listeners so announce mikes went to mono, paralleled across the stereo bus.
That's why you need only one mic preamp per mic channel.
You will need the power supply for the mic modules.
It sounds as if you have the others and if they work, they're fine to power the others you have.
If your power supplies are pooched, you can easily buy regulated 48 volt supplies on Ebay.
Get the Chinese ones.
They work fine and I'm running my AT242 wired as a mic preamp with one and it's absolutely quiet.
You'll have to hard wire them in, because you probably won't be able to find the matching plugs for the existing receptacles.
Just make sure to get ones with enough amperage which you should be able to find out from the instruction manuals.
The 24 volt supply is for relays, etc, to mute speakers and run "on the air" lights.
Some of these boards came with monitor amps, some without.
As I mentioned with the Lethbridge board, we used a speaker/monitor amp made by McCurdy, a wedge you hung on the wall and plugged into the board and ac.
You can also find transformers with the same values to replace the missing ones.
Hammond made all the McCurdy transformers, they're just painted McCurdy blue instead of Hammond grey.
They're still in operation and make some of the best transformers in the world.
And there should be a screw or screws or some type of latch on the upper tray of amps on the right side, which allows the rack to tilt up similar to a car hood for easier access to the bottom row.
As per your conjecture as to what happened to the missing modules, you're correct, they likely were poached for use in another identical or similar board. Any engineer worth his or her salt would have pulled all the usable components from the board before scrapping it.
These parts are worth a lot of money to people in your position who need them to refurbish their boards.
One further comment: The beauty of these modular boards with the amps, power supplies, etc on plug in boards made it easy to configure the inputs the way you wanted them.
Some people wanted the control room mike on channel 5, others on channel five and some even on channel one.
You're pretty much free to set up the order of the pots the way you want by moving the input modules around and simply selecting which channels you want to mute the control room speaker and trigger the on air lights.
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Mon Apr 01, 2013 2:34 am

Thanks for the insight Mike, as always. Didn't know about the mic on left in stereo boards, so just shows how technically inept I am. I'll probably leave the config the way it is with CR mic on CH 4, but were I to move things around...does this suggest that if I take the MT 244 A modules out of CH 1 (currently for tape decks etc) and swap them out with an AT 240 A, then the mic will magically come up on CH 1 without changing any of the wiring? I just assumed that if the mic currently comes up on CH 4, it's because the mic is wired into CH 4. Is there a second step I'm missing?
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Re: Vintage McCurdy broadcast desk

Postby scott s. » Mon Apr 01, 2013 1:52 pm

Don't beat yourself up too much. In dealing with this stuff, experience is the greatest teacher. It's a heck of a learning curve until then, but you are more fulfilled in some cases because of it with your new found knowledge.

Manuals are far from perfect, and can leave out missing info or are not written well. I have some of the old ITC 3D manuals and 750 series reel to reel manuals. They can get my head spin. They are written to explain how the whole unit works, and not necessarily the piece you are concerned about. you have to learn how it works first. That happens all too often.

My stereo QRK 3D manual was a pain when I tried to hook a relay up to the mic pot switch. The manual said you could switch via internal relay, but all the terminal strip connections are listed within the manual....EXCEPT the one I needed....I needed to know what pins to connect to and took sometime to figure out that the actual pins listing for that relay are on a larger fold out schematic, and not in the book. Who knows why that happened, but things like this happen with manuals.

An email last night sent to McCurdy about the 8820....hopefully i'll hear back from them
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Re: Vintage McCurdy broadcast desk

Postby Mike Cleaver » Mon Apr 01, 2013 2:12 pm

Yes, that was one of the great things about modular boards, the ability to swap channels to place them in the order you want them.
Simply place the module, mic or line, into the channel slot where you want to use it.
Then, re-wire the input to the module to the correct source and change the jumpers (IIRC) to enable monitor mute and on air light activation for the channel to which you've switched the mic.
That will also mute the cue speaker when you switch on the mic.
Channel 4 was usually the most used CR mic position with the most used channels fanning out on either side, the least used the further from the operator, such as TT right on 3, TT2 on 5, right cart (or cart bank) on 6, left cart (or cart bank) on 2, etc with tape machines, remote lines on the others.
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Re: Vintage McCurdy broadcast desk

Postby GordoGibbo » Mon Apr 01, 2013 2:20 pm

I assume the AT 240 and AT 240 A are the mic modules, and the MT 244 and (maybe AT 242) are line modules?
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Re: Vintage McCurdy broadcast desk

Postby Mike Cleaver » Mon Apr 01, 2013 9:38 pm

The AT242 is what McCurdy called a universal amplifier.
It can be strapped as a mic pre, a line amp, a program amp and can even provide enough output to drive a cue speaker.
The other modules in the 240 series came along a little later, except for the ones that are just a transformer to isolate and match line inputs to the board.
Think of them as building blocks with the input device-the AT 24- series module as the preamplifer or line isolater- the program amp and then the board output.
Then there's the cue/intercom amp, speaker and muting when the CR mic is on.
The various power supplies send power to the various modules.
Originally, they all ran on 48v DC regulated.
Yours appears to have others that run on a different voltage plus the unregulated supply for the muting and lighting relays.
Glad you've been able to source the parts.
There's a Ward Beck user's group on the 'net.
Possibly, those of you who own McCurdy gear could start one as a place to exchange information, swap or sell surplus parts and exchange experiences with the various products.
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