Audio wiring with punchdown.

[TheSigma]

Anyone got suggestions or comments on audio wiring with punchdown blocks? 66? 110? ADC? others?

Here's what I know, which mostly relates to 110 blocks. They are designed for 22-26AWG solid conductors, and you can have problems with using stranded conductors (so I've heard, I've alwasys followed the rules). I have only used these for phone lines and networking though. any reason I should not wire audio with them? I am getting ready to rebuild a studio and the boss wants to have a breakout from the console (so we never have to open the thing up to access any of the I/O's in the future. So it is kind of like a patchbay, except we really don't plan to make changes all that often. I'm not sure what the existing wiring is but I don't want to have to replace it all because it is stranded or the wrong gauge to work in the punchdown block. Has anyone used the ADC ICON blocks? are they more tolerant of wire gauge/type? By the way this is for an FM radio station on air studio.

Thanks.

Edit: Corrected AWG for 110 blocks.

[RGORJANCE]

I have been using the 66B3-50 blocks for about 20 years in many locations These locations were both at co-located sites and RF clean locations. One site had a 5kw AM and two FM's sat 6kw, class A. More about that site later.

I have used both solid and stranded wire with VERY FEW problems. The trick is to use a good quality punch tool with a very sharp cutting edge. (and watch out for whiskers)

My personal preference is the GEPCO blue covered multi pair with 16 pairs as it works out to 48 wires on a 50 position punch block. I do not like their digital version of the wire for punching down as it has a very thick insulation, and smaller gauge wire. It gets a bit tough as it tends to be less robust than the analog series wire. The analog cable is really nice to work with and actually, both versions contain colored jacketing and individually numbered pairs. Easy for us older guys with failing eyesight, reduced mental agility, etc.

I will have to search for some photos of the layout for you, but it may take a day or two to locate what I am after. The shots should help you with the planning. I'll also try to locate a layout sheet I made up for the assignments of the audio sources, etc.

I did install some of the ADC stuff some many years ago, and it was acceptable. Only did it once, and therefore have limited background with it.

Fossil
audio sources, etc.

[TheSigma]

Thanks for the info. Now you say the ADC was acceptable, does that imply that you still prefer the 66 block? I'll look into that Gepco multipair, sounds like a good way to go and I've used and love gepco cable, but haven't used their multipair. I use Mogami multipair in my home recording studio, but the particular type I use is definitely too fragile for punchdown.

[Deep Thought]

Whatever you decide, I'll second Fossil's very sharp blade comment. I haven't done any large-scale studio wiring for a couple of decades but what I do usually involves 66 blocks and both solid and stranded twisted pair. Never had a problem as long as the punch tool was sharp.

[RGORJANCE]

I must be having sequential and multiple senior moments today. The picture I attached really ain't a punch block layout. It's an RCA BTA-1R - DUHHHHH!

The ADC system I helped install, I suspect, was chosen due to a very limited amount of room real estate. It went in without problems, and has been satisfactory. It seemed to me more awkward to work with, but in fairness, it could have been "merely different".

The large punch block installation in Racine was at a co-located AM/FM with the AM tower less than 50 ft. away from the blocks. We had the luxury of a basement and a long wall section to use. We placed 4 X 8 by 3/4 inch plywood sheets on the walls. We ran 2 inch copper strap connected to station ground across the top of the plywood. We categorized and ran the punch blocks top to bottom to top vertically down to near the floor. We then ran 2 inch strap down between the columns of blocks. This meant that there we had a single point station ground, hopefully eliminating ground loops.

So, column one was one studio, another column was sat rcvrs, another couple were for the audio distribution amps, etc. We run Audio Vaults and so we had both analog and digital audio to deal with. The advantage of the straps were that we could use a scope to snoop for RF and then with combinations of clip leads and bridge clips we reduced/eliminated the RF and then made permanent punch down ground leads with spade lugs which we screwed down to the copper strap. Quick, simple, cheap and clean.

Additionally, balanced audio is very important to clean audio and maximum inherent RF reduction/elimination.

As a result, we ended up with a physically clean/RF clean system. Covers were placed over the punch blocks with labeling to present easy identification for troubleshooting/additions, etc.

If you have any questions, shoot me a private email and maybe we can get topgether via phone.

Fossil

[NECRAT]

It's an RCA BTA-1R - DUHHHHH!
Fossil

Maybe when you think of punching things, you think of the RCA BTA-1R??

[RGORJANCE]

Be nice now. I can remember when that stuff was "state of the art"!

I'm really happy that electronics advanced as fast as it has. Boy was that gear crude! "Hmmmmmm, did I spell that last word right????

Fossil

[Muadeeb]

I'd like to throw a vote in for ADC's Krone blocks. They fit in the space of a condensed 66 block, and can handle 50 pair (32 shielded audio). They also have a test port between the trunk side and the local wiring. The trunk comes in the middle, and local is out on the sides, and it works with a standard 110 tool, but there is a special Krone tool that has scissors for the cutting side. It is also possible to double punch on one set of contacts, but I wouldn't recommend it if you don't have to.

As for the trunk wiring, I like to second the Gepco, but would use the digital stuff (DS616). That is the 26 guage, but is actually easier to work with than the 24. The ESPN facility in Dallas is wired with this stuff, as is the AM and News studios at WBKV. The trick is to remember that the jacket and the shield are SEPARATE, so use a light touch. For local, use Belden 1800B (bonded jacket) for digital, and Gepco 61801EZ for analog/control.

And Bob, I'm assuming that was RJN's BTA?

[RGORJANCE]

Yes, that was the one in Racine. We gave it away to a good home. A friend in Milw. has a personal museum, and has some xmttrs he restored, and he has a super clean MW-5A that could fire up and work super fine if need be. He also got the BC-1T from West Bend that he may already have restored. He really was after that one.

Fossil


PS - pardon the temp thread derail

[davek]

This may be slightly off topic, but I note no one had mentioned using Cat 5e/6 cable for facility wiring. It's certainly cheaper and easier to terminate than individually shielded mutli pair cables, and works for just about every type of signal commonly used in modern radio stations.

I work for a major Australian radio company and our entire flagship facility is cabled with unshielded Cat 5e, with the only exception being the patchbays which are cabled using Belden 1424A. Granted we are not in an RF environment in the city, but even at both our transmitter sites all cabling is done using shielded Cat 5e. The only exceptions are the reticulated RF CATV feed for the TV's around the office, and the fibre optic cables used to transport signals between our Klotz routers. All punchblocks used are all Krone Highband8.

One last observation, digital audio does not have to be treated like analog audio. It is perfectly happy running over unsheilded cable over hundreds of feet. It often amazes me how many facilities I've seen that buy expensive multipair shielded cables for running what is essentially RS422 data. Cat 5e/6 is used everywhere to handle 100 megabit and even gigabit ethernet, occupying far more bandwidth than humble AES!

[RGORJANCE]

Point well made. I forgot about the cat5. Friend of mine just did a studio with it and it was fast.

Fossil

[TheSigma]

I am aware that you can use cat 5e/6, there is a whole line of products called studiohub+ that are based on just that principle. however, I think we are hoping to re use whatever existing cabling we can. Perhaps a little more background is in order. I am working part time at this sattion, sort of an engineer in training (my background is pro audio, electronics, video production, little RF). My boss (and good friend) is the chief engineer/owner, and it is a non profit station (southern Gospel). we recently replaced the Custom automation system with a Wide Orbit Automation for Radio system. There are two on air studios, and one production studio. studio B was already upgreaded before we put in WOAFR and now we need to do studio A. After the upgrade, both will have Radio Systems Millenium digital consoles. Right now we are waiting on some new cabinetry, the old stuff is already pulled. As soon as the cabinetry is done we are going to wire up the Millenium, hook up the touch screens for WOAFR (the rest of the system resides in an equipment room), wire up the studio mics and telephone hybrid and that's pretty much it, if we are basically cloning studio A, then there is not even a cd player to hook up or anything. So all the satelite feeds, automation feeds, etc, are already run, on whatever cable was used at the time (the station has been around since the 80's). We are not co located with the TX, it's on top of a mountain a few miles away. The only RF is the STL, and CATV, so it should not be a terribly hostile environment.

Looks like it should be ok then to use the punch blocks, I just wanted to make sure we weren't looking at trouble with intermittent problems or any other Gotcha's.

Thanks for all the tips guy's,
Nathan

[BroadcastDoc]

I'm a fan of the 66 blocks. I usually keep a few punch tool tips handy if I'm doing a big project.

I know of some people who swear by the ADC's Krone blocks. Once you get the hang of them, they're pretty easy to use, and you can do some neat things with them. On the other hand, you REALLY can't beat the simplicity and utility of the good ol' 66.

If you can, try and find yourself some old 3M ST Connectors (3M doesn't make them anymore, but I know there are similar ones out there). You can crimp them on to wires and "plug" them right on to a 66 block. They're great for quick patching jobs, or when you need to "double-punch".

[RGORJANCE]

Here is a sheet I made up to document punch block wiring, If you look at the left hand side, you will notice the lines printed. This space corresponds to one stereo audio source. There is also room at the right if you want to show where that source ends/terminates. Feel free to use the form, or roll your own version. I keep a loose leaf binder at each place I wire for future documentation and changes/additions/deletions.

Fossil

PUNCH BLOCK FORM.xls

(22 KiB) Downloaded 276 times

[davek]

Our facility is documented in VidCad now, oh for the days of keeping wiring records with pencil and paper!!!