SC-28 length modification

[photobiscuits]

Does anyone have any experience in modifying the length of the measly 3ft SC-28

cord? It seems a fairly simple process to chop this cable in half and then

splice another 10 feet or even 20 feet of wire in between the ends to have a

more usable length.<br>

Have any advice on any dangers to doing so? Does anyone know the maximum length

of Nikon Approved cable I can use between my D40's hot shoe and my SB600?

Called Nikon to ask but they're tight lipped about discussing modifications.<br>

I'd buy the transmitter and do away with wires altogether but they are expensive

so wires it is. Thanks.

[ellis_vener_photography]

if the SC-28 is liek the SC-17 the easiest way to make a longer cable is to link up to three of them together. I know from experience that you can hook together 2 SC-17 cables to move flash up to about 15 feet from the camera.

[JAPster]

I have not tried this. But i studied electricty in college. So, when you increase the length of your conductor, by adding extra wires, you are going to increase the amount of resistance (ie, Ohms), in the whole cable. That, in turn, will lead to slghtly higher voltage drop across the cable when current is running through ( E = I * R ). And I think that will result in your having slghtly less DC voltage levels at the flash contact points. Probably not enough to advsersley impact the flash operation, as long as all your Batteries are fresh and fully charged.

 

Make sure that the conductor wires that you insert are at least as thick as the ones in the original cable, or thicker, so that cable retains its full current carrying capacity. If I were doing it, I would solder the wire ends together, then cover the solder points with plastic screw-on caps, followed by black electrical tape.

 

If the cable was being used for digital transmission purposes, (ie, like a SCSI hard drive cable), you might introduce signal time delays into the transmission lines, and that might cause problems for hi-speed digital signals that are supposed to stay within certain clock cycles of each other.

 

But in this case, you are using it to drive your flash. The extra length of cable is going to cause the very slightest amount of time delay between the two units. But probably not enough to adversely affect flash operation. You probably send only DC voltage across the cables, and that is pretty low level DC (less than 12V).

 

Practically, you want to make sure you use good strong reliable connections that will be able to stanbd up to lots of activity. You dont want to be shooting a wedding, and then experience a connection failure at either of the joints, which will be under the tape. That would break your cable in the middle of the shoot, and would put you in a tight spot.

 

Of course, once you get the cable finished, test it out with you camera and flashes, and evaluate the quality of the pictures. If your pictures looked the same as they did before, then the cable is OK.

[alex_lofquist]

If you are going to splice several lengths of cable, I'd recomend using crimping splices, such as made by Vaco or Turner & Betts. You can get the insulated ones or just use heat shrinkable "spaghetti" over the splices. Then cover the whole area with a larger heat shrink PVC sleeve. This makes a more durable cable than one covered with tape.

Of course, if you're handy, you could replace the cable portion with a single length. Radio Shack usually has shielded cable of sufficient gauge.

[photobiscuits]

Great! I am going to give it a shot and blame myself if it doesn't work out. Thanks for the advice on the electrical specifics, that's what I was really wondering about. I think I found what I am looking for at Radio Shack, "4 wire, 24 gauge, stranded" for only 8 bucks for way more than I need (50 feet) so if that's the right gauge (will have to cut the cable to see) then I'm in business for little money. I'll ask for the shielded stuff and see what it's price will be. I also like the idea of the shrinkable sleeve - will look into that as well. Great ideas!<br>

I already have the solder, flux and iron, got electricians tape but will look for this heat shrink stuff because you're right, I want a strong joint.<br>

In the SB-600 manual it says you can hook up to 5 flashes together and specifies a maximum total cable length of 33 feet, so I figure about 15 feet added should be enough to give me some elbow room with plenty to spare should I add another flash in the future.<br>

Thanks guys, wish me luck, will post the results in this thread.

[joseph_wisniewski]

I've dome more than one of these over the years. You are not going to do this without soldering. Crimp on connectors won't mate with the Nikon cables (about 28 gauge) and the extension cable (more likely to be about 22 gauge).

 

The very best way to "splice" Nikon flash cables is to solder in 6 pin mini-DIN or mini-XLR connectors. You need four conductor shielded cable, which may not be available at Radio-Shack. The shielded cable is necessary because the camera and flash communicate with high speed serial data.

 

Do not worry about "resistance". Even rather thin four conductor shielded won't add more than about an Ohm per foot, and the Nikon flash control lines have pull ups and terminators in the hundreds or thousands of Ohms. Even 50 feet of cable will still be reliable.

 

If you ware going to actually splice, without using connectors, get some small heat shrink sized for the individual wires and some larger heat shrink that can go over the entire cable. Strip the jacket on the Nikon cables back about an inch, and the individual wires about 3/4 inch. Strip the jacket on the extension cable back about 2.5 inches, the wires 3/4 inch, and slide 1 inch pieces of heat shrink over the wires (that's why we stripped the jacket so far back).

 

Mini-DIN are cheaper and lighter than Mini-XLR.

 

Mini-XLR are near indestructible and don't crunch the way Mini-DIN do when stepped on.

 

Mini-XLR latch, Mini-DIN don't. Latching connectors don't come undone unexpectedly, but at the same time, cables that don't latch provide a "safety" feature when someone trips over the cable, it just unplugs instead of tripping people or knocking over light stand or camera.

 

Another wizfaq

[jim_momary]

Mike - As a capable electronic tech, and former ham radio guy who is pushing 60, go for it. The amount of current in the trigger is negligible & time delays here are meaningless; taking into account the RC with wire being copper, delay will be in fractional microsecs if not nanosecs. I've extended, eons ago, a cheapie Honeywell strobe to 110 ft away from the camera synch terminal. No issues but wrapping and storing the cable.

I'd suggest to forget the crimps and wirenuts IF you can solder. Depending on the wire count in the cable, cut each progressively staggered with respect to neighboring wire (this avoids the snake swallowing a rat bulge in the finished cable). Slide on skinny heatshrink for each soldered connection. Also slide on a couple layers of larger heatshrink for the entire cable. Carefully twist together each connected pair and solder neatly. Slip the tiny heatshrinks back over each joined pair. Shrink the tubing. Pull the bigger heatshrink over the main bundle, shrink and viola. The soldered joints get 'unified' by being bunched together and the larger heatshrink acts like a strain relief, within reason. I've done this hundreds of times putting together PLC cables, special motion control stuff and other proprietary PC cabling in my factory. Unless you hang the flash on it and swing it around like a bolo, it'll do fine with minimal 'ugly'. Yell if you need further advice. Jim M.

[joseph_wisniewski]

Ellis - "if the SC-28 is liek the SC-17 the easiest way to make a longer cable is to link up to three of them together."

 

The SC-28 is almost, but not quite, like the SC-17. The big difference is that the SC-28 has a cable that exits from the side on the camera end, which makes for an awkward mid-cable splice.

 

"I know from experience that you can hook together 2 SC-17 cables to move flash up to about 15 feet from the camera."

 

Did you "relax" them? Two of my SC-17 are "relaxed". One just did it naturally, the other I "cooked" a little and let it cool "stretched" to take a bit of the curl out of it.

[frank_skomial]

"In the SB-600 manual it says you can hook up to 5 flashes together and specifies a maximum total cable length of 33 feet," - you must have a much better SB-600 Manual than I do. I cannot find anything about cable connection of multiple SB-600 and any cable limit to 33 feet, or limit on number of flashes to 5. Please, help me finding this, by providing page number ? Are you sure you found this information in SB-600 Manual ?

 

While extending SC-28 cord makes sense for SB-600, as that would extend the reach and preserve the iTTL auto flash lighting with a single corded compatible flash, this will not work with multiple SB-600 flashes and D40 in any auto flash exposure mode.

 

Ths SB-28 does have multiple flash terminal designed for older cameras, but NOT for the D40 camera and the iTTL flash mode. Your D40 camera uses iTTL, (not TTL, not D-TTL), and only one SB-600/SB-800 flash can operate on the cord in this iTTL auto mode.

 

You would have to give up automatic flash exposure with SC-28 and multiple SB-600 connected to your D40 camera, and use all flashes in Manual mode, and determine exposure yourself, using a flash meter or by experimentation.

 

Are you sure you still want to ruin your SC-28 cord ?

[joseph_wisniewski]

Jim speaks with great wisdom, and much more detail than my own explanation. The staggered splices can really neaten the overall appearance.

 

"The soldered joints get 'unified' by being bunched together and the larger heatshrink acts like a strain relief, within reason."

 

Jim, have you ever used the Ray-chem heat shrink with the adhesive liner? Get the outer cable jacket clean, and the adhesive melts and binds to it and you get a splice that you can, as you put it, "swing it around like a bolo". Also wonderful for maintaining the water resistance of the cable.

 

The world sucks. I wanted to find a nice picture of a Westinghouse splice to show Mike, googled "Westinghouse splice", and got just two hits, neither of which are useful. Did knowledge of the splice die so long before the birth of the internet that the two never intersected? More to the point, are we that old?

[jim_momary]

Yeah Joe, we are that old ... crikeys, where are my teeth???!!! ... The adhesive lining that melts, oozes and seals is almost as good as a chocolate bar. Works super well, if one practices first. To the novice it can make a mess. It works super marvey (tech term) when I do low voltage lighting and want to bury the splice. Newark Electric, Allied, Graybar and others even supply/used to supply 'tees' and 'crosses' of adhesive lined heatshrink, so you can have a real solid three-way or four-way splice too (sort of like a manifold or simple wire harness).

 

See here for splice diagram (Western Union modality)... http://www.markhellerelectric.com/wusplice.pdf ... pages 12-16 of the pdf give a fairly layman-proof demonstration. Well anyway, 'why the heck chop up a perfectly decent wire', as my better half would ask .. to wit I respond 'because I can'. Silly Jim M.

[photobiscuits]

Excellent information guys! I actually searched before I posted but could find nothing specific on the topic, so there's another great bit of info for the archives.<br>

Frank Skomial, the information on connecting flashes and maximum combined cable length is on page 67 of the <a href=ﾓhttp://www.nikonusa.com/pdf/manuals/Speedlights/SB-600.pdfﾔ>SB-600 manual</a>. It also makes mention of shooting in manual/TTL mode with multiple flashes but since I have only the one flash for now I haven't researched it yet.<br>

Anyway, I went to Radio Shack and asked for help, cut the SC-28 in half right in the store and the salesman helped me find the right gauge (he recommended 24 gauge stranded speaker wire. Also he recommended butt-end connectors for the connections, though I would have preferred solder myself I went with what he suggested. In all the project cost $10.00 and about 1 hour of time while watching the hockey game.<br>

In the end I have a working cable that is now a usable 15' long and I'm very happy that I tried it and thanks to everyone for their suggestions, that really gave me the confidence I needed (thought I might be risking burning something out).<br>

The cable's ugly and yep, big rat bulges at the connections but for the low cost I am very happy. Some excellent construction advice was given here after I completed the project, so when this one falls apart I know what to do come repair time.<br>

Thanks a lot for the advice and the help, everybody. This is something I would recommend to anyone reading this thread, at your own risk of course. The freedom of being able to move around your model is well worth the little cost.<br>

cheers!

[photobiscuits]

Edit: The hyperlink for the manual didn't work, it is here:<br>

http://www.nikonusa.com/pdf/manuals/Speedlights/SB-600.pdf

[frank_skomial]

Thanks for the Page 67 information.

 

On page 66 states that with CLS and non-CLS DSLR cameras, multiple flashes connected with cords possible only in Manual mode.

[photobiscuits]

Thanks Frank, I'll keep it in mind for the future upgrade. I'd love to have 1 or 2 more of these little beauties.

[joseph_wisniewski]

This is true. In order to connect multiple flashes with wires and preserve CLS features, you need a microprocessor controlled arbitration unit. As far as I know, the only such device in the entire world is sitting right here. It's getting better all the time. One of my goals is to release it this summer, PBKA style. (your choice: plan, board, kit, or assembled unit). I haven't done a PBKA in years.

 

The current prototype arbitrates four Nikon flashes. It's just beginning to do CLS, but can at least capture messages. It's fully conversant with the older flash protocol and from one master panel can simultaneously zoom (or lock the zoom) on all the flashes, set them all to the same power, sequence them in variable power, at variable high speed timing.

[joseph_wisniewski]

Jim, neat read. "Solder pots", that's even before my time, but I remember reading about them.