[Amps] Spring Channel Nuts
jim.thom at telus.net
Sat Jul 8 00:59:07 EDT 2017
Date: Fri, 7 Jul 2017 23:11:18 +0000 (UTC)
From: Roger Parsons <ve3zi at yahoo.com>
To: Amps <amps at contesting.com>
Subject: [Amps] Spring Channel Nuts
<Please forgive me if this is the wrong forum.
<I have been happily building an amplifier and other things into an old 19" BC transmitter cabinet. The cabinet is quite old but in good condition. Unfortunately, it did not come with the rear door, and I am not very happy about having lethal voltages around with <no protection. So I thought - easy - I will fit panels to the rear which will be useful for connectors anyway.
<The cabinet has fixing channels in it which are basically unistrut, and there are horizonal ones at top and bottom which take standard (spring) channel nuts. So that bit really is easy. There are also vertical channels at the back which is where I want to fix my <panels and these are much smaller. To use those I need channel nuts which are approximately 10.5mm across the flats. I know that these (did?) exist as I have the three that were used for the original door. But I need more and as far as I can see, they make <hens with teeth seem pretty common.
## who makes the cabinet ?? All my hammond cabinets use .25” holes on the front + rear vert rails.....no horz rails at all. Then the spring loaded nuts are slid into which ever holes you want to use. Typ spring loaded nuts are the
10-32 variety...sold by any hammond dealer...in bags of 25-50-100 etc. Then the mating 10-32 chrome machine screws with the chrome cups. On my newer hammond racks, they use vert rails that are already drilled and tapped for 10-32 screws.....a ton of em in each of the adjustable 4 x vert rails. I ordered my last 2 racks with 2 rails for the front..and 2 more for the rear. All 4 x vert rails can be adjusted forwards and backwards. I also have a spring loaded, hinged rear door on top of all that. On the older racks the .25 holes could also be used with a .25-20 bolt if u wanted. easiest source for spring loaded nuts is in the hammond cabinet catalog.
## Not having the back door sucks. Rear panels will work, but have to be removed for access..which takes time. IF u mount connectors of any type on the rear panel..paneLS, u compound the issue...since the leads on the inside
of the rack have to be really long, so you can wire what ever to the inside of the connectors. U need slack to work with... so u can carefully put the rear panel into place..and not pinch any wires etc.
## On one of my smaller 19 inch racks, abt 50 inchs tall, the rf deck slides into the top portion of rack. It’s a complete al box, sealed on all 6 sides...so no danger from HV. however, its 1 inch too deep to get the back door to close.
No big issue, except that the lower portion of the same rack contains misc stuff like a 50A fil xfmr, 0-240 vac at 5A variac for fil xfmr, sola constant V xfmr, magnehelic gauge for pressure measurements, and hr meter for fil etc, etc. Lower part of rack needs to be sealed off for safety, so the only fix was a panel to cover the lower portion at the rear of rack. 9.5 inch Square hole at very bottom of rack is where the air filter goes..with rack up off the ground on casters. Bottom portion of rack needs to be sealed anyway, so all the air entering the filter, is via the bottom 9.5 x 9.5 square hole and its mating filter....and not bypassing the air filter, by coming in the lower back exposed portion of rack. So its either a rear door..or a rear panel. Door wont close...so the lower panel is the only option. pita, since a lot of connections are also on that rear panel.
## my new racks are deeper...and the rear door uses the same spring loaded, quick release hinge at the top..and a fixed hinge pin at the bottom. So the rear door can be opened..or closed...and also be completely removed in 2 secs.
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