Looking for professional reviewers to test VIOFO A139 3 channels dash cam

SawMaster

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I'm concerned about the sharp bend in the coax. What usually happens is that over time, the inner conductors press on one side of the insulation which softens under heat, allowing it to 'migrate' closer to the outer shielding even to the point of shorting out, but at the very least changing the impedance of the coax. Rather than a sharp bend can you do something like this:
Coax.png
The 'loop' won't affect anything.

PhilCoax.png
 

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I wonder if you could buy an even shorter cable somewhere which would work, I believe the cable is rg-174?
 

SawMaster

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Not sure what the cable is, although the diameter (and so the minimun bend radius) are similar to RG-174. The real issue is likely the connectors which are a sort I've never encountered before. If those are proprietary in nature we will have to rely entirely on Viofo for our cables, but such as that almost never happens as there's a large array of connectors already made for use with various coax, and using those in production is always much cheaper and more profitable for the manufacturer of the device.

Phil
 

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Not sure what the cable is, although the diameter (and so the minimun bend radius) are similar to RG-174. The real issue is likely the connectors which are a sort I've never encountered before. If those are proprietary in nature we will have to rely entirely on Viofo for our cables, but such as that almost never happens as there's a large array of connectors already made for use with various coax, and using those in production is always much cheaper and more profitable for the manufacturer of the device.

Phil
A quick search makes me think they may be an MMCX plug, looks similar in pictures but I haven't measured. MMCX Datasheet
 

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@viofo I think a short 10-15cm coax cable would be a good option for those of us who have the interior camera very close to the main unit
EDIT: As an optional extra, not default in the box
 
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SawMaster

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Would be nice to have some different lengths available as accessories :)

Phil
 

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If placing the cabin camera on the mirror stalk was not a option in my car, my #2 location would be over near the far A pillar and then aimed towards the driver ( which would necessitate some modding to the camera to not allow for adjustment Left to Right )
If a shorter cable was availebel i would have to buy one, with as many cameras as i have in the car some times, having surplus cable tucked away at the windscreen are not a good idea.
 

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Actually in some places my headliner are starting to sag a little at the edge after all those times i have worked with it over the years.
 

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Gitup F1+G3ꞈꞈꞈꞈꞈ Viofo A139ꞈꞈꞈꞈꞈ Blueskysea B4K+B2K

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yeah I haven't seen it, I'm sure it would be an off the shelf connector though, not something you're going to see in your local electronics store or whatever as it's very specific use case
 

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Gitup F1+G3ꞈꞈꞈꞈꞈ Viofo A139ꞈꞈꞈꞈꞈ Blueskysea B4K+B2K
There do seem to be extension cables fairly widely available, seem to be used for some radio control stuff.

(I'm not 100% sure that is what it is.)
 

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Definitely not MCX. I don'r have the dimensions to check, but it does look more like MMCX based on what I've seen at this point. My reference book on connectors is in storage somewhere, haven't used or seen it in ages. My digital caliper is there too so I wouldn't be able to confirm anything at this point.

Phil
 

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I'm concerned about the sharp bend in the coax. What usually happens is that over time, the inner conductors press on one side of the insulation which softens under heat, allowing it to 'migrate' closer to the outer shielding even to the point of shorting out, but at the very least changing the impedance of the coax. Rather than a sharp bend can you do something like this:
View attachment 54095
The 'loop' won't affect anything.

PhilView attachment 54095

I'll try to take it out and just let it loop around somewhere, maybe around the mirror stalk. It's not going to look pretty, but this is a test install after all. There really isn't enough space in the headliner to do anything else other than to squeeze it in. The A129 cables aren't making things easier.
 

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Actually in some places my headliner are starting to sag a little at the edge after all those times i have worked with it over the years.
Mine sags a little, and there's usually a rattle or two from loose cables or unused mini-USB plugs tucked away up there.
 

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I'll try to take it out and just let it loop around somewhere, maybe around the mirror stalk. It's not going to look pretty, but this is a test install after all. There really isn't enough space in the headliner to do anything else other than to squeeze it in. The A129 cables aren't making things easier.
It is a valid test, there will be others that install it in the same way, you should leave it as it is and test it!

I don't expect it will be an issue with the short cable anyway, a fold in the longer cable might be more serious, although I think it is capable of transmitting significantly further than the long cable length; not sure how far it can carry the power but the signal should go a lot further.
 

SawMaster

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The overall length doesn't matter regards minimum bend radius; it's a physical limitation of the cable itself more related to it's diameter and the physical qualities of the insulation inside of the cable.

The length could matter regards data. Coax can cause standing wave reactions if it's not cut to specific lengths which correspond to wavelength, so an altered or aftermarket cable of the wrong length could affect performance including EMI susceptibilities but I kind of doubt that will happen here.

An old non-scientific 'rule of thumb' regards bend radius in coax is to lay it on a table gently creating a "U" shape which you close in slowly- where it begins springing back against you laying there loose will be close to it's minimum allowable bend radius. The way the rear cam cable is coiled up for shipping in the box is pretty close to the minimum bend radius you want to have ;) Too tight may not show up as a oproblem immediately; the usual movement of the center conductor through the insulation is slow hence why it's called "migration". Prior to the point of shorting out what effect migration may have here I don't know, but it's best to avoid the potential for problems.

Phil
 

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Dont know how it stack up against the thick USB cables i have been used to handle for remote cameras, those i also try my best not to bend too much.
These thin cables would be more easy to route thru rubber cable ducting at rear hatches and doors, i am a little apprehensive about when i will move the DR system to rear doors for use as side cameras.
 

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Hello
I would be very interested in reviewing this new triple channel camera. I've used my trusty Mini 0806 with GPS for years. I would be happy to review on both Amazon UK and Amazon US and provide feedback. Feel free to DM me.
 

HonestReview

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Hello
I would be very interested in reviewing this new triple channel camera. I've used my trusty Mini 0806 with GPS for years. I would be happy to review on both Amazon UK and Amazon US and provide feedback. Feel free to DM me.

They dont have any more. We missed the boat.
 
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