(part 1 of 2)
As you may know from my shack pictures and other Scanner Tales I have an obsession with rack-mounting my radios as well as changing the layouts on a seemingly weekly basis. The reason I change the layouts so often is multi-tiered; I get something new; things change at home or perhaps I was bored and wanted to change things. As for rack-mounting there are good reasons. These include being able to hide wires and accessories like multi-couplers, USB hubs and power supplies. The main reason however is to appease my wife. She is the reason I started doing it in the first place. She saw some rack-mounted radios at the 9-1-1 Center I was in charge of as well as a big networking cabinet with the recorders and servers used there and said I should do that at home.
Rack-mounting also allows one to rearrange things within the rack pretty easily. This is important for me as I change my shack around often. Rack mounting is not for everyone, however. It can be expensive and affects future changes and expansion. It can also reduce access to the wiring end of radios and devices. Not all equipment lends itself well to rack mounting but if you are skilled in metal and woodworking or have the financial means you can overcome those issues.
At the time my radios were mostly set up on Elfa shelves, with most of the wires tied up in bundles under the desk or stashed as best I could. When we replaced some older base radios at work, I was able to scavenge an old half-height GE cabinet that had held a Mastr-II base radio. I had an Astron 50-amp linear power supply at the time to power stuff, so I was able to stash that beast in the cabinet and hide it from view.
Next, I was able to get some Motorola CentraCom-II parts and that allowed me to rack-mount radios for daily use. It worked out really well when my stepson moved in, and we gave up my office for his bedroom for a couple years. I moved that unit to my room across the hall and was able to keep some radios running until his new house was ready.
A few years later I got the rack-mounting bug big time. A friend who ran another 9-1-1 center near me had set up a free-standing 10u cabinet between the two 9-1-1 positions to hold shared devices like a scanner, backup radio and MDC decoders. He sourced much of the equipment from a place called “NorthComm” out of the NYC area. I thought it was a great idea so copied it at my 9-1-1 center. When the wife came by to visit, she saw that and said I should do the same at home so I could hide all the crappy wiring. I took an inventory of my equipment and contacted NorthComm. After a few email exchanges they proposed 3 10u cabinets and custom panels to handle my radios. These included JottoDesk faceplates to mount the specific radios and 3 Astron 25A power supplies, one for each cabinet. The whole shebang arrived in several large (and heavy!) boxes a couple weeks later. I spent the weekend putting together the cabinets and mounting the radios, leaving the wiring to the very end in case I changed the layouts.
A few years after that we moved across the country. At first, I reassembled the three cabinets and all was well with the world. My wife however didn’t like how the 3 different cabinets laid out in the office and recalled the fridge-sized networking cabinet I had in my 9-1-1 center. She suggested that that might be a better idea, and I agreed. We found a 42u cabinet with rollers, a ventilated rear door and a plexiglass front door on Amazon and a couple days later it arrived. I again spent a weekend setting it all up, pretty much with the existing radios but in a single large cabinet. That lasted 5 or 6 years and I got my money’s worth out of it for sure.
As I retired from my retirement job, I started to downsize my radio collection to the stuff I interacted with all the time. I had also figured out the lay of the land in the area, so I no longer needed so many radios to search the spectrum. I had been using a bunch of BCT15’s to search out the MilAir bands and some GREs to collect data on the local P25 stuff.
I tried out some horizontal racks as well as some vertical ones and eventually settled on a single 10u cabinet that I used off and on for a couple years. I did spend some (well, a lot) money on custom rack panels, but I have a need to do it right, so it was worth it.
So, I tell you all that to tell you this: If you want to rack-mount your stuff there are some things to know. You can spend a lot of money or do it on the cheap (if you are handy enough).
Rack History:
The rack stuff we know today originated over a century ago when the phone company started to standardize relay mounting. Relays were the basics of telephony then and phone companies used hundreds of them along with tons of associated equipment. By standardizing the size and layout they could easily expand the systems as the country (and their equipment needs) grew. The systems then migrated to other industries and pretty soon many other industries standardized on 19 and 23-inch racks. While 23-inch racks (the measurement between the cabinet edges) are these days still used by some telephone equipment, most computer and communications equipment use 19-inch.
These specifications were then used for all kinds of gear and when computer servers and networking gear (Routers, switches etc.) proliferated they were usually built to mount in the existing equipment. The music industry also adopted these standards, and I have had great success sourcing stuff from companies that specialize in supplying the musically minded.
Rack Math:
When you decide to rack-mount your stuff you need to know a few things. You should use standardized rack specifications so that if you buy parts and accessories commercially, they will slot tight in. You can make your own cabinetry if you are able and save a boatload of cash or if you have more money than skills like me, you can buy the stuff commercially.
The math includes the vertical, horizontal and depth measurements. Once you know this stuff the rest comes pretty easily.
The standard rack is 19 inches across, measured within in the vertical framework. Assuming that the mounting rails are each ½ inch wide this provides for 18 horizontal inches for the equipment.
For vertical measurements the “Rack Unit” is the standard measurement. A Rack Unit (shown as “u”) is 1 ¾ (1.75) inches tall. Panels are supposed to be a tad shorter to allow for some breathing room. This ensures that gear doesn’t bind if the tolerances are too tight. If you have a panel that is 2u that panel is slightly less than 3.5 inches tall. 3u is just under 5.25 inches and so on. If they made the panels in exact multiples of 1.75 inches then they would be too tight to easily install and remove.
Depth is less standardized but often less critical. Full-sized 42u open racks have metal frames only, so the depth of the equipment doesn’t matter so much. Enclosed cabinets have different depths. Typically, “Server Cabinets” are deeper than “Network Cabinets”. Typical depts for Server Cabinets are around 40-50 inches deep while Network Cabinets range from about 30 to 36 inches deep. The depth you need is usually based on the deepest equipment you are going to mount. For radios the shallower Network Cabinets are usually just fine.
Smaller cabinets as would more typically be used for the scanner users range from 10 to 20 inches deep for a cabinet up to 12 or so rack units. 13 inches in depth seems to be the sweet spot for my radios, but your needs might differ.
Then there is the mounting holes situation. Larger cabinets often use “Cage Nuts”, these are square nuts with captive clips that fit into square holes on the rack rails. You snap these Cage Nuts into the rails where your equipment mounts and then the screws that hold the rack panels in place screw into these. These are most often found in free-standing cabinets.
Smaller desk cabinets typically have threaded rails using 10-32 machine screws. There are 2 different standards for the spacing of the holes, however. Most equipment uses “3-hole” spacing but some uses the newer “4-hole” layout. The number refers to the number of holes in a 1.75 inch Rack Unit. I suggest that if you get equipment be sure that it matches the layout on the cabinet rails. Alternately (and like I have done) you can drill and tap your own holes in the rails as needed. Usually at least one hole per side with fit existing holes even if the alternate standard is used so you can mount the gear with one screw per side and drill/tap a new hole where needed.
Desktop enclosures or cabinets come in 1, 2 or 3 horizontal bays so you can spread things out horizontally as well as vertically. If you only have a few things to mount, then you can use a single-bay rack of up to 12u to contain radios. Depending on the rack panels you use, and the radios involved this could contain up to a dozen or more small radios.
Multi-bay desk cabinets are available or could be made at varying heights to allow many radios without stacking them too high. Add about ¾ of an inch or so (assuming ¾ inch wood is used) to each side to the 19-inch panel width to determine the final width of the cabinet, so a single bay cabinet would be about 20.5 inches wide, 2-bay would be about 40.25 inches and a 3-bay cabinet about 60 inches.
Home Made Racks:
If you decide to roll your own then you can customize the height and depth to meet your needs. I do suggest that you keep the height to a specific amount of Rack Units to allow the use of commercial panels. These are usually the hardest thing to customize so are then most often purchased commercially.
If you have decent carpentry skills, you could make your own rack cabinets. Remember that the space between the inside walls should be 19 inches. The height of the cabinet should be in multiples of 1.75 inches, again measured from the inside top and bottom. Consider making it larger than you need now and fill in the extra space with blank panels so that you can add radios later.
For the side rails you can buy pre-made rails from AudioRax or other sources. If you are really handy you can get some ½ inch metal angle stock at Home Depot type places. You can get a drill and tap for the screws and add the holes as needed or even just use sheet metal screws.
For the panels, you can buy commercial or make your own. For my first cabinet at work, I took a street sign blank to a local HVAC company that had a metal shop. They cut the sign to the proper size (19 inches wide by 14 inches (or 8u) tall) and then cut holes to fit 6 JottoDesk faceplates for the various radios to be mounted. They then powder-coated it black to match the faceplates.
I have seen some guys make panels out of plywood, aluminum or steel stock. It all depends on your skills and budget. Basically, you are building a frame box. No front is needed as that is where the radios go. As for the back you can leave it open to allow work and ventilation. Just be sure the box is square and sturdy. I don’t have the carpentry skills, so I buy my cabinets, mostly from AudioRax.
Weight Issues:
Usually radios rack-mounted will not be too heavy so no extra support is needed. If you have a particularly heavy item like a linear power supply or a huge radio, then you might need to add extra support. For example: Astron makes a line of rack-mounted power supplies, they use thicker mounting panels to support the higher weight. Another example are the rack panels made by NovexCom for large Icom, Kenwood and other ham radios. They come with shelves to hold the weight; the front panel is basically aesthetic.
Computer gear:
Since similar rack-mounting protocols are used for computer servers and networking gear you can repurpose some of the gear intended for computers for your radio stuff. For instance, rack-shelves are an easy way to rack mount gear that doesn’t have rack-mounting capabilities with it. These shelves can hold radios and accessories just by placing them on the shelves. Blank panels can be purchased and then modified with holes to mount radios or accessories.
Be careful however about mounting your computers and networking gear in the same cabinets as your radios. The servers, switches, routers and other computer equipment can be RF-noisy and cause interference with your scanners. If you do share cabinets, be sure to try the radios with the computers turned off and compare noise levels with the computers turned on to see if there are issues. Sometimes good grounding will prevent serious issues.
(Continued in part 2)
As you may know from my shack pictures and other Scanner Tales I have an obsession with rack-mounting my radios as well as changing the layouts on a seemingly weekly basis. The reason I change the layouts so often is multi-tiered; I get something new; things change at home or perhaps I was bored and wanted to change things. As for rack-mounting there are good reasons. These include being able to hide wires and accessories like multi-couplers, USB hubs and power supplies. The main reason however is to appease my wife. She is the reason I started doing it in the first place. She saw some rack-mounted radios at the 9-1-1 Center I was in charge of as well as a big networking cabinet with the recorders and servers used there and said I should do that at home.
Rack-mounting also allows one to rearrange things within the rack pretty easily. This is important for me as I change my shack around often. Rack mounting is not for everyone, however. It can be expensive and affects future changes and expansion. It can also reduce access to the wiring end of radios and devices. Not all equipment lends itself well to rack mounting but if you are skilled in metal and woodworking or have the financial means you can overcome those issues.
At the time my radios were mostly set up on Elfa shelves, with most of the wires tied up in bundles under the desk or stashed as best I could. When we replaced some older base radios at work, I was able to scavenge an old half-height GE cabinet that had held a Mastr-II base radio. I had an Astron 50-amp linear power supply at the time to power stuff, so I was able to stash that beast in the cabinet and hide it from view.
Next, I was able to get some Motorola CentraCom-II parts and that allowed me to rack-mount radios for daily use. It worked out really well when my stepson moved in, and we gave up my office for his bedroom for a couple years. I moved that unit to my room across the hall and was able to keep some radios running until his new house was ready.
A few years later I got the rack-mounting bug big time. A friend who ran another 9-1-1 center near me had set up a free-standing 10u cabinet between the two 9-1-1 positions to hold shared devices like a scanner, backup radio and MDC decoders. He sourced much of the equipment from a place called “NorthComm” out of the NYC area. I thought it was a great idea so copied it at my 9-1-1 center. When the wife came by to visit, she saw that and said I should do the same at home so I could hide all the crappy wiring. I took an inventory of my equipment and contacted NorthComm. After a few email exchanges they proposed 3 10u cabinets and custom panels to handle my radios. These included JottoDesk faceplates to mount the specific radios and 3 Astron 25A power supplies, one for each cabinet. The whole shebang arrived in several large (and heavy!) boxes a couple weeks later. I spent the weekend putting together the cabinets and mounting the radios, leaving the wiring to the very end in case I changed the layouts.
A few years after that we moved across the country. At first, I reassembled the three cabinets and all was well with the world. My wife however didn’t like how the 3 different cabinets laid out in the office and recalled the fridge-sized networking cabinet I had in my 9-1-1 center. She suggested that that might be a better idea, and I agreed. We found a 42u cabinet with rollers, a ventilated rear door and a plexiglass front door on Amazon and a couple days later it arrived. I again spent a weekend setting it all up, pretty much with the existing radios but in a single large cabinet. That lasted 5 or 6 years and I got my money’s worth out of it for sure.
As I retired from my retirement job, I started to downsize my radio collection to the stuff I interacted with all the time. I had also figured out the lay of the land in the area, so I no longer needed so many radios to search the spectrum. I had been using a bunch of BCT15’s to search out the MilAir bands and some GREs to collect data on the local P25 stuff.
I tried out some horizontal racks as well as some vertical ones and eventually settled on a single 10u cabinet that I used off and on for a couple years. I did spend some (well, a lot) money on custom rack panels, but I have a need to do it right, so it was worth it.
So, I tell you all that to tell you this: If you want to rack-mount your stuff there are some things to know. You can spend a lot of money or do it on the cheap (if you are handy enough).
Rack History:
The rack stuff we know today originated over a century ago when the phone company started to standardize relay mounting. Relays were the basics of telephony then and phone companies used hundreds of them along with tons of associated equipment. By standardizing the size and layout they could easily expand the systems as the country (and their equipment needs) grew. The systems then migrated to other industries and pretty soon many other industries standardized on 19 and 23-inch racks. While 23-inch racks (the measurement between the cabinet edges) are these days still used by some telephone equipment, most computer and communications equipment use 19-inch.
These specifications were then used for all kinds of gear and when computer servers and networking gear (Routers, switches etc.) proliferated they were usually built to mount in the existing equipment. The music industry also adopted these standards, and I have had great success sourcing stuff from companies that specialize in supplying the musically minded.
Rack Math:
When you decide to rack-mount your stuff you need to know a few things. You should use standardized rack specifications so that if you buy parts and accessories commercially, they will slot tight in. You can make your own cabinetry if you are able and save a boatload of cash or if you have more money than skills like me, you can buy the stuff commercially.
The math includes the vertical, horizontal and depth measurements. Once you know this stuff the rest comes pretty easily.
The standard rack is 19 inches across, measured within in the vertical framework. Assuming that the mounting rails are each ½ inch wide this provides for 18 horizontal inches for the equipment.
For vertical measurements the “Rack Unit” is the standard measurement. A Rack Unit (shown as “u”) is 1 ¾ (1.75) inches tall. Panels are supposed to be a tad shorter to allow for some breathing room. This ensures that gear doesn’t bind if the tolerances are too tight. If you have a panel that is 2u that panel is slightly less than 3.5 inches tall. 3u is just under 5.25 inches and so on. If they made the panels in exact multiples of 1.75 inches then they would be too tight to easily install and remove.
Depth is less standardized but often less critical. Full-sized 42u open racks have metal frames only, so the depth of the equipment doesn’t matter so much. Enclosed cabinets have different depths. Typically, “Server Cabinets” are deeper than “Network Cabinets”. Typical depts for Server Cabinets are around 40-50 inches deep while Network Cabinets range from about 30 to 36 inches deep. The depth you need is usually based on the deepest equipment you are going to mount. For radios the shallower Network Cabinets are usually just fine.
Smaller cabinets as would more typically be used for the scanner users range from 10 to 20 inches deep for a cabinet up to 12 or so rack units. 13 inches in depth seems to be the sweet spot for my radios, but your needs might differ.
Then there is the mounting holes situation. Larger cabinets often use “Cage Nuts”, these are square nuts with captive clips that fit into square holes on the rack rails. You snap these Cage Nuts into the rails where your equipment mounts and then the screws that hold the rack panels in place screw into these. These are most often found in free-standing cabinets.
Smaller desk cabinets typically have threaded rails using 10-32 machine screws. There are 2 different standards for the spacing of the holes, however. Most equipment uses “3-hole” spacing but some uses the newer “4-hole” layout. The number refers to the number of holes in a 1.75 inch Rack Unit. I suggest that if you get equipment be sure that it matches the layout on the cabinet rails. Alternately (and like I have done) you can drill and tap your own holes in the rails as needed. Usually at least one hole per side with fit existing holes even if the alternate standard is used so you can mount the gear with one screw per side and drill/tap a new hole where needed.
Desktop enclosures or cabinets come in 1, 2 or 3 horizontal bays so you can spread things out horizontally as well as vertically. If you only have a few things to mount, then you can use a single-bay rack of up to 12u to contain radios. Depending on the rack panels you use, and the radios involved this could contain up to a dozen or more small radios.
Multi-bay desk cabinets are available or could be made at varying heights to allow many radios without stacking them too high. Add about ¾ of an inch or so (assuming ¾ inch wood is used) to each side to the 19-inch panel width to determine the final width of the cabinet, so a single bay cabinet would be about 20.5 inches wide, 2-bay would be about 40.25 inches and a 3-bay cabinet about 60 inches.
Home Made Racks:
If you decide to roll your own then you can customize the height and depth to meet your needs. I do suggest that you keep the height to a specific amount of Rack Units to allow the use of commercial panels. These are usually the hardest thing to customize so are then most often purchased commercially.
If you have decent carpentry skills, you could make your own rack cabinets. Remember that the space between the inside walls should be 19 inches. The height of the cabinet should be in multiples of 1.75 inches, again measured from the inside top and bottom. Consider making it larger than you need now and fill in the extra space with blank panels so that you can add radios later.
For the side rails you can buy pre-made rails from AudioRax or other sources. If you are really handy you can get some ½ inch metal angle stock at Home Depot type places. You can get a drill and tap for the screws and add the holes as needed or even just use sheet metal screws.
For the panels, you can buy commercial or make your own. For my first cabinet at work, I took a street sign blank to a local HVAC company that had a metal shop. They cut the sign to the proper size (19 inches wide by 14 inches (or 8u) tall) and then cut holes to fit 6 JottoDesk faceplates for the various radios to be mounted. They then powder-coated it black to match the faceplates.
I have seen some guys make panels out of plywood, aluminum or steel stock. It all depends on your skills and budget. Basically, you are building a frame box. No front is needed as that is where the radios go. As for the back you can leave it open to allow work and ventilation. Just be sure the box is square and sturdy. I don’t have the carpentry skills, so I buy my cabinets, mostly from AudioRax.
Weight Issues:
Usually radios rack-mounted will not be too heavy so no extra support is needed. If you have a particularly heavy item like a linear power supply or a huge radio, then you might need to add extra support. For example: Astron makes a line of rack-mounted power supplies, they use thicker mounting panels to support the higher weight. Another example are the rack panels made by NovexCom for large Icom, Kenwood and other ham radios. They come with shelves to hold the weight; the front panel is basically aesthetic.
Computer gear:
Since similar rack-mounting protocols are used for computer servers and networking gear you can repurpose some of the gear intended for computers for your radio stuff. For instance, rack-shelves are an easy way to rack mount gear that doesn’t have rack-mounting capabilities with it. These shelves can hold radios and accessories just by placing them on the shelves. Blank panels can be purchased and then modified with holes to mount radios or accessories.
Be careful however about mounting your computers and networking gear in the same cabinets as your radios. The servers, switches, routers and other computer equipment can be RF-noisy and cause interference with your scanners. If you do share cabinets, be sure to try the radios with the computers turned off and compare noise levels with the computers turned on to see if there are issues. Sometimes good grounding will prevent serious issues.
(Continued in part 2)
