Author Topic: How to attach an RCA connector to a chassis ?  (Read 12691 times)

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Offline langwadt

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Re: How to attach an RCA connector to a chassis ?
« Reply #25 on: October 03, 2018, 02:22:26 pm »
it was temperamental and I got up on a chair to mess with it and boom. Probably got nudged because you know, you need to move home AV equipment to clean the dust under it *unless your a dirty fuck*

Never would have happened with BNC. Obviously people won't have it so poorly set up but the fact is the equipment needs to be moved once in a while to clean behind, under it, etc, unless its part of a sterile AV rack mount device.

There is like a 100% chance some house wife is going to be regularly messing with some kind of home audio setup to find dust during regular cleaning. Maybe some people will have a filtered AV cabinet under their TV with some fan and filters to change, but I never saw that.

I think it is much more common that messing with the cables behind home audio is something that might happen once per decade
 
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Offline Bassman59

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Re: How to attach an RCA connector to a chassis ?
« Reply #26 on: October 03, 2018, 05:12:09 pm »
well the design also allows you to zap the center conductor with ESD easily. especially in a shagged out audio room.

same problem with the audio connectors.

everyone so mad, god guys, buyers remorse from 20 years ago? everything is optical now for good reason. war's over people, japan surrendered in the 40's, no point defending this jungle anymore

All audio gear should use balanced connections on XLR. None of this RCA stuff. I demand that all consumer audio manufacturers switch over immediately. Also, Pin 2 hot.

{waiting forever}
 
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Offline Richard Crowley

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Re: How to attach an RCA connector to a chassis ?
« Reply #27 on: October 03, 2018, 06:01:41 pm »
to be specific, i never noticed that much of a problem with BNC, i found even crusty old ones worked fine, but always a decent brand
Wow, what great good luck you have had.

I have had 10x (or perhaps 100x) as much trouble with BNC as I ever had with RCA.
Yes, RCA are big, clunky, crude, etc.  But that makes them much more easily repairable in the field when a million-dollar production is on the line.

OTOH, I wish I had a buck for every flaky BNC connector I have had to deal with in the heat of battle.
They are small, fiddly, fragile, and ill-suited for field production.  But, alas, there is no reasonable substitute and virtually 100% of modern digital video gear uses them.  Of course, digital video (HD-SDI) uses the 75 ohm version of BNC which makes especially the female connector extremely fragile.

I try to keep "disposable/consumable" 90-degree angle fittings on my cameras, etc just to save the fragile BNC connector. But ignorant "help" doesn't know any better.  Perhaps I can super-glue the disposable adapter onto the camera to protect the fragile camera BNC connector.  I would be quite happy if I never had to deal with another BNC.
 

Offline coppercone2

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Re: How to attach an RCA connector to a chassis ?
« Reply #28 on: October 03, 2018, 09:19:35 pm »
What do you consider a BNC fail? The worst I had were with ancient function generators, the BNC from the 1960's or whatever looked really chowdered, but in the end they still seemed to work pretty well even when wiggled at low signal levels (I did not wanna take stuff apart).. I don't think I ever ended up replacing any of them on old test equipment I bought on ebay, though when badly tarnished and stuff I expect them to have bad HF performance in the high MHz.

The only BNC problem I noticed was with no-name BNC adapters meant for computer connectors ( 10BASE2 or whatever the network standard that used BNC was). But I played with them ALOT when I was a kid.. but I just made a rule if it does not have Pamona or such written on it I throw it out. The no-name BNC splitters are HORRID, but that is to be expected IMO. But I abused the hell out of them, because they were kinda fun to mess with because they formed rotary locked joints. Also the fact that I had them as a kid meant that they were recovered from a dumpster.

RCA was a completely different story, perfectly fine connectors connected to things like cameras, TV attachments would often require maintenance for no good reason


If you want a kinda permament but not really mounting for BNC then consider using Loctite. Purple would be recommended. I tried this before with a BNC and it kinda held a bit better, but it was still easy to twist off once you gave it a bit of force, but it certainly feels stuck compared to what your used to.
« Last Edit: October 03, 2018, 09:32:20 pm by coppercone2 »
 

Offline Richard Crowley

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Re: How to attach an RCA connector to a chassis ?
« Reply #29 on: October 03, 2018, 09:30:31 pm »
I consider intermittent or COMPLETE absence of the signal to be a "BNC failure".
The cause is typically the female center contact deforming so that it doesn't make contact anymore.
So I have to go in VERY CAREFULLY and bend the contact segments back toward the center to make contact with the male pin.
My great fear is that one of these days the female center pin contacts will just snap off and I will have a completely useless $10K video camera sitting there.

I am thinking of very carefully putting a piece of heat-shrink tubing over the exposed female contact to keep it from so easily deforming.
But, of course that will throw off the impedance.  But maybe not enough to destabilize the link.
And it could interfere with mating with 50-ohm male connectors.  What a mess.
 

Offline coppercone2

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Re: How to attach an RCA connector to a chassis ?
« Reply #30 on: October 03, 2018, 09:33:24 pm »
try loctiting (purple or if thats not enough blue threadlocker) on a connector to see if your comfortable with it. I bought male-female adapters for this reason to put on equipment I am using frequently. But I don't have to deal with stooges.

The purple stuff is weak but it might discourage yanking.

Also, if you don't give a shit, you can solder them together carefully with a powerful iron, but the thing might melt, and you need to use an agressive flux.

From experience soldering them (to make sealed connections in really ghetto enclosures) you need alot of heat and fast or the plastic heats up and expands and destroys the connector or gets burned and the impedance probobly changes).

The little gasket will probably be destroyed though, but thats only effecting the one commonly not attached to equipment with moving parts. By destroyed I mean it suddenly requires massive pressure to turn but still works fine. They have the dielectric (teflon I think) in a slug around the middle, but some have like a rubber o-ring under the rotatable part that tends to get destroyed. But, I think if you had like a 150W soldering gun, you might be able to do it, with agressive flux, so it does not damage anything, if you tin a spot on both, cool them completely, then bridge the tinned areas when their mated.

A less nice solution would just be to get thin steel wire, or maybe piano/painting wire, wrap the mated connection fairly tight, then seal the wire with a crimp/ferrule so it stays tight after you twist it together on the end, then just give it a trim. This way someone would need (decent) wire cutters to undo it to remove the sacrificial connector. If someone knows their tools they might be discouraged from using their field kit to cut steel wire, unless they have nice carbide cutters etc.
« Last Edit: October 03, 2018, 09:45:35 pm by coppercone2 »
 

Offline tooki

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Re: How to attach an RCA connector to a chassis ?
« Reply #31 on: October 03, 2018, 11:34:59 pm »
You’re just trolling us now, right? It has to be trolling. Cuz it’s either that or the ramblings of a lunatic.
 

Offline coppercone2

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Re: How to attach an RCA connector to a chassis ?
« Reply #32 on: October 04, 2018, 01:28:25 am »
NOTE: This message has been deleted by the forum moderator Simon for being against the forum rules and/or at the discretion of the moderator as being in the best interests of the forum community and the nature of the thread.
If you believe this to be in error, please contact the moderator involved.
An optional additional explanation is:
« Last Edit: October 04, 2018, 10:31:23 am by Simon »
 

Offline Cerebus

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Re: How to attach an RCA connector to a chassis ?
« Reply #33 on: October 04, 2018, 01:46:12 am »
You’re just trolling us now, right? It has to be trolling. Cuz it’s either that or the ramblings of a lunatic.

why don't you post something relevant dumbass

A rude lunatic then, glad that's sorted.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline jh15

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Re: How to attach an RCA connector to a chassis ?
« Reply #34 on: October 04, 2018, 04:30:00 am »
I agree the RCA is ok for home consumers. It has a 'how you doin' impedance for rf.

BNC failures come from video people a lot due to the different dimensions of 50 and 75 ohm connectors.

They may borrow cables from a bench instrument and plug into a pro monitor or verse visa.
 I like hermaphrodite connectors such as on my GenRad stuff and Anderson powerpoles (for power, not impedance.)
Tek 575 curve trcr top shape, Tek 535, Tek 465. Tek 545 Hickok clone, Tesla Model S,  Ohio Scientific c24P SBC, c-64's from club days, Giant electric bicycle, Rigol stuff, Heathkit AR-15's. Heathkit ET- 3400a trainer&interface. Starlink pizza.
 

Offline Simon

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Re: How to attach an RCA connector to a chassis ?
« Reply #35 on: October 04, 2018, 10:31:09 am »
why don't you post something relevant dumbass

Why don't you calm down before you get banned?
 
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Offline bd139

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Re: How to attach an RCA connector to a chassis ?
« Reply #36 on: October 04, 2018, 11:38:39 am »
Wow this thread turned to shit didn't it.

I occasionally use RCA for RF when I run out of BNCs and want to do something *right now*. They work fine up to 20W or so and under 30MHz with no measurable reflection (RL no different to straight termination) or heating. My portable linked dipole also has the links done with RCA inline connectors. Absolutely fine so far. Even used them for power on occasion. Yellow ones for power. Black ones for RF. Red ones for audio. It doesn't matter if you stick the wrong things in the wrong holes either because there's a DC block on all the audio and RF holes.

Have I've given everyone cancer with that admission?  :-DD

I rarely get any problems with any connectors because I don't buy crap ones, I look after them, replace them when they are worn out and I terminate them correctly. That's the winning combo.
 
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Offline Cerebus

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Re: How to attach an RCA connector to a chassis ?
« Reply #37 on: October 04, 2018, 01:34:54 pm »
Have I've given everyone cancer with that admission?  :-DD

Possibly, but you're the kind of bloke who thinks that a BLU-82 "Daisy Cutter" is "less bovver than an hover [mower]" and that Redi-mix is a lawn treatment, so we've learned to filter your advice.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline bd139

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Re: How to attach an RCA connector to a chassis ?
« Reply #38 on: October 04, 2018, 01:44:42 pm »
I'm only concerned with getting from A-B not who gets in the way while I'm getting there :D
 

Offline CJay

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Re: How to attach an RCA connector to a chassis ?
« Reply #39 on: October 04, 2018, 02:12:17 pm »
My uncle bob was severely injured in a freak RCA connector incident, I too have not been able to move on.







 :-DD

I had a really bad experience with an RCA connector in 'nam*, there was a murder** and a mass brawl***



*Tottenham, it was a mobile DJ set.

** On the dancefloor

*** Everyone**** was KungFu fighting.

**** Surely not 'Everyone'?
 
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Offline macboy

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Re: How to attach an RCA connector to a chassis ?
« Reply #40 on: October 05, 2018, 05:59:46 pm »
I agree the RCA is ok for home consumers. It has a 'how you doin' impedance for rf.

BNC failures come from video people a lot due to the different dimensions of 50 and 75 ohm connectors.

They may borrow cables from a bench instrument and plug into a pro monitor or verse visa.
 I like hermaphrodite connectors such as on my GenRad stuff and Anderson powerpoles (for power, not impedance.)
75 and 50 ohm BNC are entirely safe to inter-mate because all contact dimensions are identical. The 75 ohm version simply does not have the dielectric within the mating area, which increases the impedance. The N type RF connectors do have different dimensions in the mating contacts and will be damaged by inter-mating. Many people assume the same for BNC, but it is not true.
I copied the following two sets of diagrams from one of Amphenol's spec sheets.
 
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Offline Richard Crowley

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Re: How to attach an RCA connector to a chassis ?
« Reply #41 on: October 05, 2018, 06:27:42 pm »
Yes the common 50-ohm BNC connectors are mechanically interconnectable with the (more rare) 75-ohm version.
As @macboy says, the problem is that the center contact of the female 75-ohm BNC is essentially unsupported (without any dielectric mechanical support) and that makes it extremely vulnerable to any but the most careful connection.  I have lost count of how many times a camera feed goes dead just before the program starts because some female 75-ohm BNC connector has gone intermittent because of deformed center-contact pin.  Typically on the camera output or the switcher input.
 

Offline jh15

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Re: How to attach an RCA connector to a chassis ?
« Reply #42 on: October 07, 2018, 04:37:32 am »
I stand corrected about the conductor dimensions.

I learned during ISF training that 75 and 50 ohm bnc connectors do not play nicely with gorillas or stage hands.

Now I need to know about  n connector interfacing dimensions that I recently forgot. What's the story there? Something about the pin. I am worried not to damage my antenna analyzer.,
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Offline CJay

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Re: How to attach an RCA connector to a chassis ?
« Reply #43 on: October 07, 2018, 08:56:32 am »
I stand corrected about the conductor dimensions.

I learned during ISF training that 75 and 50 ohm bnc connectors do not play nicely with gorillas or stage hands.

Now I need to know about  n connector interfacing dimensions that I recently forgot. What's the story there? Something about the pin. I am worried not to damage my antenna analyzer.,

Pin diameter of a 75R N connector is, I think, smaller than a 50R pin
 

Offline langwadt

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Re: How to attach an RCA connector to a chassis ?
« Reply #44 on: October 07, 2018, 03:06:34 pm »
Yes the common 50-ohm BNC connectors are mechanically interconnectable with the (more rare) 75-ohm version.
As @macboy says, the problem is that the center contact of the female 75-ohm BNC is essentially unsupported (without any dielectric mechanical support) and that makes it extremely vulnerable to any but the most careful connection.  I have lost count of how many times a camera feed goes dead just before the program starts because some female 75-ohm BNC connector has gone intermittent because of deformed center-contact pin.  Typically on the camera output or the switcher input.

I seems to remember reading that the 75 and 50 ohm BNCs became compatible by some standard that came out in the 70's,
the story that they aren't just keeps popping up
 


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