Bringing out rear BNCs on rack equipment trick - Page 1
Forum section: electronics / testgear

author: Berni
author_rank: Super Contributor
timestamp: January 25, 2017, 05:27:42 pm
content: A lot of test equipment has extra BNC connectors on the back and we all know how annoying they are to get to.To get to the back of my rack i have to move it forwards away from the wall on wheels, its not hard but still anoying. So i thought about screwing in a BNC patch panel, but that is something id have to make or buy so i been looking at the rack some and realized it has lots of holes already on the front in the form of standard rack rails. Unluckily standard rack rail holes are not large enough to install a panel mount BNC connector in them, however a SMA connector is easily small enough to fit trough.So there are panel mount bulkheds that go from SMA to BNC but need a SMA sized hole for mounting, bought a bunch of them and added in some washers to make sure it fits well (Hole is tiny bit too big) All of this is stacked up as shown with the screwdriver representing the rack rails wall.All of this is screwed on to the rack rail as shown here and a SMA cable carries the signal off to the back. Additionally the large washers provide room to write down what that BNC is for. In this case the modulation and auto gain control input of a Gigatronics 6100 synthesizer.Other end of the coax simply terminates in to BNC and goes to the corresponding ports on the back .So here is what it looks like when done, pretty sleek looking i think for the little work it takes to put together and if you use Chinese parts and cables its pretty cheep too.

author: bitseeker
author_rank: Super Contributor
timestamp: January 26, 2017, 08:19:40 am
content: Cool. I remember someone here also brought their BNCs to the front of a rack. I don't remember which thread it was in. What he did was drill some holes in a 1U blank and mounted the BNCs in it. Pretty slick.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 27, 2017, 07:19:37 am
content: That's a nice idea. The only trouble is that usually rackmount gear has rack brackets. (Should have, to avoid disasters.) So there's rarely unused sections of the struts.Putting connectors in a 1U blanking panel is the usual way. Or you may be 'lucky' enough to have some gear that isn't a multiple of standard rack units (like my TLA721) so you can use a bit of plain L-section to fill up the odd gap, and put connectors in that.A last resort is that some rack cabinets have a side gap between the upright strut, and the outer shell. In which a bracket can be mounted. I'm about to do that in one of my racks. Both for connectors and a couple of power switches.

author: Berni
author_rank: Super Contributor
timestamp: January 27, 2017, 07:46:37 am
content: That does look a lot more professional of a setup. I should proabobly at some point get a blanking plate and mount them over on to that.And yeah the reason this works for me is that some of the equipment i got does not have rack mounts on it, so as a alternative i have some rack mount shelves in there that i set the equipment on top of. I find that if there is rubber feet on them that it does not really move all that easily from the shelf. As a result the feet on equipment disturb the rack rail spacing so i do have some narrow gaps between equipment where a half U blanking plate could fit.But i think this quick and dirty method is still good for just a few BNCs and you might even have such a SMA to BNC adapter laying around in a box of RF connectors.

author: bghende
author_rank: Contributor
timestamp: January 27, 2017, 06:35:12 pm
content: Nice hacking. Doesn't look too bad and cheap.If you have more budget, I have used these in the past:http://www.l-com.com/patch-panel-server-rack-175-panel-16-75-ohm-bnc-adapters-insulatedNot too expensive once you factor in the cost of 16 bnc's and mounting hardware.

author: bitseeker
author_rank: Super Contributor
timestamp: January 27, 2017, 07:28:04 pm
content: If you're using rack shelves and live in an area where the earth likes to party unexpectedly, these will minimize flying equipment.

author: Berni
author_rank: Super Contributor
timestamp: January 27, 2017, 09:52:14 pm
content: That BNC rack plate looks quite well, id guess its made for video broadcast/processing racks with it being 75 OhmAnd don't worry earthquakes never happen here, they rarely happen in the entire country even, and if they do they at best cause a crack or two in old buildings that are already falling apart anyway.I was thinking of also adding a toggle switch or two on the rack rails like that so that i can easily switch off the power. A lot of the gear in my rack has ovenised oscillators in them so they keep them warm even when the piece of equipment is switched off so i keep it disconnected from power and just wait a little bit for it to warm up when i do want to use it.

author: bitseeker
author_rank: Super Contributor
timestamp: January 28, 2017, 01:11:55 am
content: Quote from: Berni on January 27, 2017, 09:52:14 pmThat's good. Well, the info is there for general consumption.

author: Berni
author_rank: Super Contributor
timestamp: January 28, 2017, 07:52:43 am
content: Quote from: bitseeker on January 28, 2017, 01:11:55 amBesides its full of old heavy boatanchors so it should keep the rack in place nicelyBut seriously i would be more worried about the rack tipping than the equipment falling out as the whole thing sits on caster wheels. So in a earthquake it could potentially gain some momentum before snagging on something to topple it over. It does have feet that screw out to lift it off the wheels but i like being able to move the rack for getting at the back of it or sometimes moving it closer to the work. The wheels run very smooth so its surprisingly easy to move considering the whole thing probably weighs 1/3 of a ton.

author: bitseeker
author_rank: Super Contributor
timestamp: January 28, 2017, 07:56:46 am
content: Quote from: Berni on January 28, 2017, 07:52:43 amOh, yes. Rolling around would be quite exciting, indeed.