8 core coily cable

[Iain Baird]

I hate to start a dispute but perhaps yours was an older version. I'm holding my post cable in my hand right now and the plug that joins to the upper junction box is a 2B.307 and the plug that connects to the GPI BATT II unit is a 3B.308 to mate with the ECG.3B.308 that comes with the GPI BATT II unit. When I bought my GPI BATT II unit it came with the 3B.308 and I didn't need to modify it at all for the MK-V conversion.

Edited December 13, 2007 by Iain Baird

[Eric Fletcher S.O.C.]

I hate to start a dispute but perhaps yours was an older version. I'm holding my post cable in my hand right now and the plug that joins to the upper junction box is a 2B.307 and the plug that connects to the GPI BATT II unit is a 3B.308 to mate with the ECG.3B.308 that comes with the GPI BATT II unit. When I bought my GPI BATT II unit it came with the 3B.308 and I didn't need to modify it at all for the MK-V conversion.

 

 

Actually you are correct. Bottom line is it's STILL not big enough for the correct wire gauge to be used.

[Jerry Holway]

In fact two A/B batts at full charge give off +30v and then make their way to 24 so I'm not sure if the Voltage Amp would help.

Absolutely the voltage bumper is unnecessary.

 

Voltage from 2x Lithium batteries in series hot off the charger is 33.6 volts, which under load almost instantly drops to 32 volts, then rather smoothly and slowly drops to 29.6 volts (the "knee" of the voltage curve), and then drops off very rapidly. Voltage per se should never be the issue with these batteries and the cameras we use. Other battery chemistries have different voltage curves and "knees."

 

Wasting power with improperly sized wiring and connectors is not a great design choice (yet rarely a fatal one), nor is adding unnecessary converters or voltage regulators. There's a big regulator already in all the cameras we use, BTW, and several other small ones for the electronic boards.

 

We've also neglected the 18-24 inch power cords (adding 3-4 feet to each "run", the cables to the battery, all the connectors in the line, etc., so without specific side by side testing, the amount of wasted power/dropped voltage is fairly speculative.

 

Thank modern chemistry that Lithium Ion batteries have much more power density than the good old NiCads, (but there are trade-offs).

 

With heavy draw cameras whatever situation you have is made worse... and don't forget all those other gadgets like monitors, transmitters, recorders, and obie or ring lights which also use up a lot of power and draw on the battery, tax the wiring and connectors, etc.

 

So do some tests on your own rig and see if it works with a heavy draw... if not, add a battery (about two pounds with connectors) and a separate wiring run (use 12 gauge monster cable for speakers) outside the post (horrors!) directly to the camera.

 

I think all the rigs we are talking about work, clearly some more efficiently than others...

 

Jerry

[Nicholas Davidoff]

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

[Iain Baird]

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

 

 

The 3B.309 pins are only rated for 6 amps each, even if you split the load between two power sources you are still very limited.

[Richard James Lewis]

Minor correction, the 1B's aren't any different than the 1S, XCS are 2B :)

 

rick.

 

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

[Eric Fletcher S.O.C.]

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

 

 

You can't fit a 3B lemo into the upper post collet on the Pro/MK-V. No matter the 3B.309 is a 6amp connector, and the 2B's that XCS and Tiffen use for camera power won't fit in the upper J-box

[RonBaldwin]

Where do you guys find out the max amperage for these connectors? Is it a chart on Lemo's website or aomewhere else? Jst curious as I know little about electronics/power.

[Eric Fletcher S.O.C.]

Where do you guys find out the max amperage for these connectors? Is it a chart on Lemo's website or aomewhere else? Jst curious as I know little about electronics/power.

 

 

Right on the lemo site.

 

Here's a link to one way of finding it just enter the sheel size and connector type S or B and then look for the correct number of connectors

[Iain Baird]

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

 

 

You can't fit a 3B lemo into the upper post collet on the Pro/MK-V. No matter the 3B.309 is a 6amp connector, and the 2B's that XCS and Tiffen use for camera power won't fit in the upper J-box

 

Not entirely true, the collet that the MK-V topstage comes with will only accept a 2B receptacle. But if you remove the entire collet you can install a 3B plug in it's place.

 

 

In this case I welded a washer to a strain relief collet nut for the PHG.3B.312 (seen here) and attached it to the topstage the same way the 2B collet was attached. It's perhaps a half inch longer than the original design and equally strong.

[Nicholas Davidoff]

So in an ideal world (aside from shelling out 30K on a shiny new sled with 14 gauge wire and HDSDI) how is this for an upgrade scenario for a Pro and/or MK-V sled --

 

Switch out the J-box receptacle plugs for 9 pin Lemo 3B.309's that take 14 gauge wire as well as HD. Switch the post cable with a 9 conductor/Coax hybrid cable with 16 gauge voltage lines. Install matching 3B.309's on each end of the cable. And if you really want to go all out, switch the j-box camera power outputs from Pro's standard Lemo 1S.303's to 1B.303's like the XCS. And voila, Bob's your Uncle?

 

 

You can't fit a 3B lemo into the upper post collet on the Pro/MK-V. No matter the 3B.309 is a 6amp connector, and the 2B's that XCS and Tiffen use for camera power won't fit in the upper J-box

 

Not entirely true, the collet that the MK-V topstage comes with will only accept a 2B receptacle. But if you remove the entire collet you can install a 3B plug in it's place.

 

 

In this case I welded a washer to a strain relief collet nut for the PHG.3B.312 (seen here) and attached it to the topstage the same way the 2B collet was attached. It's perhaps a half inch longer than the original design and equally strong.

 

Fine work on the j-box Iain. A very effective way to get a 3B connector in a 2B hole. I'm planing to do the same.

 

Another thing I've been wondering about is this: A look at the MK-V V3 HD J-box and you'll see there is no coax connector in the receptacle. It looks to me like a regular (non-coax) 10 pin Lemo. More specifically, a 3B.310 connector which Lemo rates at 12 amps per pin. If you can pass an HD signal through this connector (which MK-V obviously has) then wouldn't this be an ideal choice for an HD and power upgrade???

 

If this proves true, then why use a coax/hybrid Lemo 12 pin with a 9 amp rating when the 3B.310 can pass more amps? I guess with 12 pins you could use two pins each for the voltage runs vs. 1 pin each with the 10 pin plug.

 

So I guess the question is this: Which combination will pass better amps? Two pins from a 9 amp rated plug or a one pin on a 12 amp rated plug?

 

I think I answered my own question. But am I understanding this all right?

[RonBaldwin]

Where do you guys find out the max amperage for these connectors? Is it a chart on Lemo's website or aomewhere else? Jst curious as I know little about electronics/power.

 

 

Right on the lemo site.

 

Here's a link to one way of finding it just enter the sheel size and connector type S or B and then look for the correct number of connectors

 

Thanks, I knew it was there somewhere. Looks like even at 75% a y-cable and pro j-box is good to 18.75 amps. I'm curious how the newer hd pro will do with voltage loss? We had a monitor shootout...I'd love to see a side by side run time comparison. Not to see who's king of the hill (we know that'll be the xcs), but it's always nice to know what to expect. I guess it would be possible to measure voltage to see the drop as well. God I feel like a geek just suggesting such a silly thing...I'll bring non-geek beer and lisagav.

 

RB

[Douglas John Kropla]

Now I am a bit confused. The cables I use to power a 24v camera (made by PRO) are Mogami 2549. They use a #22 AWG for the current. The #20 AWG is a bit bigger and rated even higher. The wires inside my Sled are either #22 or #20 AWG and they have a 24v current running through them. I ask this out of ignorance but how can the same AWG #20 not be good enough to run 24v up the post?

 

A few things.

 

22 AWG wire is rated at 7 amps in clear air. That means NOT next to another wire, which is something that we all ignore. if we actually paid attention to that it would mean a current capacity of only 4.6 amps and that will power a film camera, well not a 435 but the rest of them. It will NOT safely power a F900, Viper, Genesis or F23 since they are all 9+ amp cameras.

 

20 AWG is rated at 11 amps in clear air or 6.6 amps in a cable pair/bundle. Still Not enough to power a HD camera.

 

XCS uses 14AWG Wire in their post which will carry 32 amps free air or 19.2 amps in a cable pair/bundle. Tiffen is also using 14awg in the U2. MK-V uses 22awg by the way and they have some other serious power issues due to voltage drop.

 

Voltage drop goes up with length of the cable run. That cable run is the length of the post cable plus the camera power cable. in a Pro with the standard post that's around 65" but voltage drop is round trip so it's a ~11ft run. For the sake of argument let's use the maximum current capacity of each wire size to figure out voltage drop. For the 22awg wire you are looking at a 4% or 1 Volt Drop. the 20awg wire will see a 3.5% or .8volt drop.

 

Lets look at 2 XCS center post's the Fixed and the expandable. The fixed post has a 6' round trip and the expandable has a 12' round trip. the Fixed Voltage drop is 2.75% or .3 volts. the expandable has a 5.5% or .6 volt drop

 

The U2 is going to have a 6.64% or .797 volts.

 

MK-V has an internal cable run of 9 feet on the four section post with it's 22awg wiring suffers a whopping 11.5% or 1.4 volt drop.

 

What does this mean? Since HD cameras are the the worst case scenario for voltage with their 11 volt shutdown, it means MK-V will shut down first even though the battery is showing 12.4 volts, Followed by the Pro at 12 volts the U2 at 11.8 and the XCS at 11.3

 

Kinda explains why I switched to an XCS Ultimate earlier this year.

 

Thank you Eric, this info is very very helpful. At least I got the wire gauge right for my own frankenstein monster.

 

I just got the exclusive rights to sell Lisagav here in Canada!!!

Edited October 25, 2010 by Douglas John Kropla

[Jess Haas SOC]

So how does Pro's new HD rig compare? What size wire and connectors is it using?

 

~Jess

[Eric Fletcher S.O.C.]

So how does Pro's new HD rig compare? What size wire and connectors is it using?

 

~Jess

 

 

other than the addition of an SDI line the power lines remain the same in the ProHD