TELCO – Page 2 – Engineering Radio

Pinouts

Over the years, I have collected many pinouts for all sorts of interfaces, connectors, jacks, etc. These are all stored on my laptop and on my smartphone. It is easy enough to look these things up online, however, there are occasions when the internet is not available for whatever reason. Thus, this is my collection of pinouts, many of which have been adapted from Wikipedia articles. Many times I put things here for my own use. However, if I have spent ten minutes looking for the USB pin out on my smartphone, someone else has done the same thing. Most of these images have higher resolutions available.

Enjoy!

EIA/TIA 568a and b ethernet cable standard

Standard networking connectors for Ethernet connections. Rumor has it that only the “A” standard is accepted for government work and the “B” standard is being depreciated.

803.3af Power over Ethernet, imposed on EIA/TIA 568 a and b

Power over Ethernet pinouts. More and more commonly used in VOIP phone systems, but can also be found in wireless access points and other things of that nature.

10/100 base T cross over cable — 10/100 base T cross-over cable

Ethernet crossover cables are useful for connecting to similar pieces of equipment together, e.g. a computer to a computer, or a switch to a switch. Many new switches have port sensing, which will automatically cross the connection if a straight through cable is used. Others have a specific port or a switch for a specific port which will cross over the cable. Gigabit Ethernet uses all four pairs, thus a 1000 base T crossover looks a little bit different.

10/100/1000 base T Ethernet crossover cable

This type cable is backwards compatible with 10/100 base T systems.

Telephone system equipment jacks.

Registered Jack (RJ) 48, commonly used on T-1 and ISDN circuits

RJ48 and 48X used on T-1 (DS-1) and ISDN connections. Since BRI and PRI ISDN are two wire circuits, the active pins are 4/5, which is the same as an RJ11. I have often used RJ11 jacks for ISDN and found no issues with doing so.

Crossover cable for T-1 (DS-1 or DSX-1 interface). Note, this is different from an Ethernet crossover cable, which will not work for in a DS-1 interface. A T-1 loopback connector goes from pin 1 to pin 4 and pin 2 to pin 5 on a 8P8C connector.

RJ21 and 21X connectors are often found on the side of punch blocks and make for quick connections on cabling trunks.

The generic 25 pair color code, which is always a good thing to have.

RS-232 data pins out for various connectors

RS-232 is still commonly used for data transfer in broadcast facilities. RS-485 is also used, however, that standard is often used with screw terminals or some other generic connection.

Null modems for connecting equipment together and testing.

Universal Serial Buss (USB) connections and pinouts

Various USB connectors and pinouts. USB has replaced RS-232 data ports on most newer computers.

Computer graphics card pinouts.

Computer parallel port pinout, not used very much anymore, replace by mostly USB devices. Can also be used as a limited GPI/GPO interface. Some small automation software programs use pins 10,11,12,13 and 15 for closure information and pins 1, 14, 16, and 17 for output switching, machine starts and the like.

PS2 mouse and keyboard connectors, again, replaced by USB but still found on older motherboards.

RJ-45 to balanced analog and digital audio

RJ-45 to balanced audio. This is a fairly standardized audio application for RJ-45 connectors developed by Radio Systems/Studio Hub. It is also used by Telos/Axia and Wheatstone, although often the +/- 15 VDC power is not included.

XLR connectors, old technology, still used

The ubiquitous XLR connector, still used for analog audio and also AES/EBU digital audio.

The Problem with the Phone Company

It they don’t care all that much about traditional phone service anymore. Through attrition, they have reduced their tech workforce to about half what it was 15 years ago. All of the infrastructure; overhead cables, buried cables, office frames, switching equipment, is getting old. Some of the cabling around here, both buried and overhead, is the original stuff, installed 100 years ago. Because it is expensive to replace, they don’t want to change it out, opting to simply limp along, swapping out pairs when a line or circuit goes dead.

I will be surprised if the traditional wired telephone network still exists in ten years. Think about it, ten years ago were just heaving a collective sigh of relief that Y2K turned out to be nothing, remember that?

For the local phone giant, offering 3 in one (telephone service, internet service, and cable TV) is more appealing than servicing their existing accounts, including HICAP (high capacity) data circuits like T-1, BRI&PRI ISDN, etc. Much less so for a POTS line, which, good luck if you really need it fixed right away, we’ll be over when we get to it, just keep your paints on mister.

I’ve written about this before. A particular station for my former employer uses a T-1 circuit to relay the program from the studio to the transmitter site. This is fairly common in larger metropolitan areas where 950 Mhz STL frequencies are not available, nor is a line of sight between the studio and transmitter site obtainable.

Back in 2002, when the company was in the process of acquiring said station, I recommended a 950 Mhz STL. There was an existing STL license, fully coordinated, that came with the main station license. Only the equipment was needed. No, I was told by the CFO, we will do a T-1, thank you very much. I argued my point, saying that putting our radio station exclusively in the hands of the phone company was a bad idea. We would have problems with outages and service. No, said the CFO, this is New York, all the radio stations do that. Not exactly, New York is about 15 miles SOUTH of here, this is Westchester, the cables are old, and a lot of them are overhead, which exposes them to lightning, vehicle damage, water, etc. There will be service issues if we rely solely on a T-1.

No, he said, “We are using a T-1 and that is final.” I hate to say I told you so, but… Let us examine the history between then and now:

Date of outage	Date of restoration	Total days
April 5, 2004	April 9, 2004	4
September 8, 2006	September 10, 2006	2
May 2, 2007	May 5, 2007	3
August 27, 2009	September 4, 2009	10
September 5, 2010	September 15, 2010	10

Fortunately, I wrote all this down in the transmitter site log. I was able to check it yesterday when I went to restore the station to normal operation after the latest T-1 failure.

During those periods, we used BRI-ISDN, which is okay but it carried the same phone cable. It is likely to go down if there is a major cable interruption. We have installed a second T-1 circuit, which fails when the other T-1 circuit fails. We have used 3G wireless sprint card and streamed audio from the internet. That didn’t sound great, but we did clear inventory. We have moved one of the AudioVault servers to the transmitter site, and updated it once a day via the shoe leather network, that sounded great, but it was difficult to do. We have borrowed an ethernet connection from another tower site tenant onsite and streamed internet audio via a wired connection, which sounds pretty good.

Still, the best thing to do would be to establish our own STL path to the transmitter and get rid of the T-1 lines.

The Problem with the Phone Company is they are not all that interested in simple copper circuits anymore. Now, there is something called FiOS, which, it would appear is a much better profit center than ordinary copper circuits.

T-1 outage

One of our stations relies on a T-1 (DS-1) to relay audio from the studio to the transmitter site (STL). This station started as a piece of paper, with no format, no staff, no real estate, and no studio equipment. There was a transmitter and an antenna installed on a leased tower site.

That being said, corners were forcibly cut. Instead of installing a microwave STL system, a T-1 was ordered because we had a T-1 multiplexor. Fast forward several years… The station is now successful, making a decent amount of money and having a popular format.

The station has two T-1 circuits on different cables with an automatic switcher. Yesterday afternoon, the inevitable happened, both T-1s went out, along with most of the other TELCO circuits in the surrounding area. A construction crew cut two 3600-pair cables a mile down the road. The TELCO is racing to restore the service to all of the tenants on that tower by rigging a temporary aerial cable.

Now the mad scramble ensues with conflicting requirements from the wacky program director. Screw it, I grabbed one of the AudioVault express machines and took it to the transmitter site. They are back on the air with a radio station in a box playing music until the T-1 gets fixed.

This site has had numerous problems since we have owned it. In the 5 years since we launched the format, there have been six T-1 outages longer than 24 hours. For backup, we have tried an ISDN line, a 3G wireless card in a computer, and a second T-1 circuit. None of these have proved reliable as most circuit outages involved a cable cut, and multiple circuits were affected.

The real solution is a microwave STL, either a conventional 950 mHz system or a 2.4 or 5.8 gHz last mile system. Either would work better than what we have now. Station ownership, they don’t want to hear it.

Update: This took until Friday, September 4th to repair, for a total outage of 9 days, 2 hours, and 26 minutes. During that time, the station remained on the air with the AudioVault server at the transmitter site and the program director updating it twice per day with voice tracks and commercials.