The connector between my speedo transducer's 10 foot wire and the long wire back to the cockpit display has 'died' from being "hidden" and underwater in the bilge for the past 29 years.
It is a BNC connector. Datamarine SX120. I have been attempting to get the two parts part for the past few days, using all the "usual suspects" to no avail.
It appears that I will need to cut both wires and install new connectors.
I am aware that there are BNC connector tools available, although the ones on Radio Shack's website have gotten poor reviews.
I will contact DMI tomorrow to determine if it is a 50 or 75 ohm connector and what the wire size is.
I would appreciate any suggestions for a proper BNC connector tool and source that actually works.
Stu. Stu, Stu...... don'tcha know that water and electrons don't mix! :donno: (or shouldn't) :think
There's a couple ways to go.... the crimp (hex) style, the compression style (like all the cable companies use for F connectors) and the myriad of push on, solder, non-solder, twist-on, etc. connectors.
I'd go with compression type -- seems to be state of the art. Well at least state of the times anyway.
ProsKit had compression terminals and the compression tools -- I have used and sold other ProsKit stuff (what I had was good quality, though not BNC.)
http://www.proskit.com/connectors/coaxial?sort=20a&alpha_filter_id=66
http://www.proskit.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=bnc+compression
Pros also carries the crimp frames and dies for different BNC barrel sizes (hex style crimp.)
http://www.proskit.com/crimpers/frames The luna and pro frames accept interchangeable dies below:
http://www.proskit.com/crimpers/dies?sort=20a&page=1
ACTUALLY, the ProsKit dies, fit the inexpensive HF crimper frame and work perfectly!
http://www.harborfreight.com/ratcheting-crimping-tool-97420.html
This is the best deal in a quality crimper frame (actually made by the same people for ProsKit Luna series:
http://www.all-spec.com/products/VDV212803.html
And accepts all the ProsKit dies.
If you go the compression type, look for "sealtite" series -- they are pretty good and the compression tools are reasonable...
Let's see what I can find...
Here you go... 10-packs aren't too bad. Do you know -- RG6... RG59... cable?
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dtools&field-keywords=%22paladin+bnc+connector&rh=n%3A228013%2Ck%3A%22paladin+bnc+connector
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dtools&field-keywords=bnc+sealtite&rh=n%3A228013%2Ck%3Abnc+sealtite
I think the two big boxes carry 'sealtite' in the F-style, maybe also in the BNCs? I guess you'll have to use a barrel connector if you can't find the mating connectors.
A new connector; some heat shrink --- and it will go another 50 years in your bilge! :rolling
Ken
Thanks, Ken, that's a great bunch of info.
I don't know what the wire is, hence my call to DMI tomorrow. It's very thin coax, only 1/8" or so diameter with the insulation.
Have you had any success of just cutting and splicing rather than trying to install connectors, or does that screw up the dialectric and the signal?
I would normally not allow this kind of thing (connector in the bilge) but I simply didn't know it was there. When doing my research and homework, I learned there is a connector from the DMI website. One could figure the factory would have installed it way up forward near the transducer, or at least somewhere you could see it. But I guess Paco was busy on Friday. :cry4`
Actually, it'd be great if I could find someone here in the SF Bay area who has a bnc crimper and knows how to use it. :D
Stu - Is it just a speed with no depth? I butt spliced the five wires for my replacement Airmar speed/temp sensor to my Standard Horizon display. Airmar has wiring diagrams for many display manufacturers. The requirements for splicing a depth transducer are beyond my current level of knowledge.
Craig
Stu,
How about "my box? -- might be easier than soldering (though you can.)
I doubt you would have any interference issues --- and only if became an issue --- then spray glue pcs of alum foil on the inside walls, back, cover.
If you solder, then the next thing is you'll need to replace the pickup.... and you're back to the beginning. :twisted:
Drop an email or PM here, they have BNC connectors --and appear to know all about DMI.
http://www.navigatorschoice.com/index.php?main_page=contact_us
Soldering:
light light heat and use heat sinks to protect the conductor insulation.
Instead of the twist-the-conductor/then solder method, I first use tinned, non-insulated crimps (Radio Shack has 24-26 AWG) followed up w/ solder -- if the cable/conductor/dielectric size makes it possible. Then heat shrink tubing over that, extended onto the dielectric.
Solder the ground/shield so it's continuous, followed by HST built up to the cable OD. For physical protection and to prevent any work hardening of the conductors, I use mil-spec (heavy wall) HST over the entire joint.
If you're concerned about signal contamination, wrap a narrow strip of alum foil around the heat-shrunk center conductor (underneath the soldered ground/shield wire so both are in contact.) Then HST the whole shebang,m I would then cover all w/ milc-spec HST for protection and triple moisture barrier.
ken
Quote from: KWKloeber on May 12, 2015, 05:41:07 AM
If you solder, then the next thing is you'll need to replace the pickup.... and you're back to the beginning. :twisted:
Ken, why would that be?
Thanks for the other info.
Craig, it's just a straight knotmeter, DM SX-120L.
Stu - Look at this page? http://faq.airmar.com/index.php?action=artikel&cat=1&id=240&artlang=en
Quote from: Stu Jackson on May 12, 2015, 08:43:13 AM
Quote from: KWKloeber on May 12, 2015, 05:41:07 AM
If you solder, then the next thing is you'll need to replace the pickup.... and you're back to the beginning. :twisted:
Ken, why would that be?
Thanks for the other info.
Craig, it's just a straight knotmeter, DM SX-120L.
Because you won't have a M-F plug there to disconnect/replace the sender -- you're back to having to replace BNCs anyway, or resolder....
Any progress?
Have you thought about "my box"? That might be the simplest and quickest? Easy to crimp on a couple mini terminal per RC's
DIY, I have the frame and that die, and it works great. Add one to the toy box.
Ken
Quote from: KWKloeber on May 12, 2015, 11:59:58 AM
Because you won't have a M-F plug there to disconnect/replace the sender -- you're back to having to replace BNCs anyway, or resolder....
Any progress?
Have you thought about "my box"? That might be the simplest and quickest? Easy to crimp on a couple mini terminal per RC's
DIY, I have the frame and that die, and it works great. Add one to the toy box.
Ken
I stopped in a ham radio place at the suggestion of some folks over on co.com. It's RG 58 cable. He gave me a male BNC connector for free, but did not have female BNC's, since I guess those are always at the back of the radios and not on the ends of the wire in the "ham radio world." This is consistent with the DMI instructions (for a new transducer):
When you remove the old SX-120 you will find it is wired exactly the same as the new one, meaning there will be the same 10' cable with a female BNC on the end. There is an interconnect cable between your knotmeter and speed sensor [SX-120]. The interconnect cable consist of a 30' run of coax cable with male BNC connectors on each end. One end mates with your knotmeter, the other end mates with the SX-120. No splicing, adapters or cutting needed. Just disconnect the old one, connect the new one and you are done. I went to the marine electronic store at the suggestion of the ham radio gentleman, and the folks there said just splice it by un-braiding the outer wire, like the photo below.
It seems easier than buying a once-in-a-lifetime use tool. I think Ken's BOX idea will work.
It's going to be brain-salad-surgery to do this with the wires on the saloon sole.
Quote from: Stu Jackson on May 12, 2015, 01:27:00 PM
Quote from: KWKloeber on May 12, 2015, 11:59:58 AM
Because you won't have a M-F plug there to disconnect/replace the sender -- you're back to having to replace BNCs anyway, or resolder....
Any progress?
Have you thought about "my box"? That might be the simplest and quickest? Easy to crimp on a couple mini terminal per RC's
DIY, I have the frame and that die, and it works great. Add one to the toy box.
Ken
I stopped in a ham radio place at the suggestion of some folks over on co.com. It's RG 58 cable. He gave me a male BNC connector for free, but did not have female BNC's, since I guess those are always at the back of the radios and not on the ends of the wire in the "ham radio world." This is consistent with the DMI instructions (for a new transducer):
When you remove the old SX-120 you will find it is wired exactly the same as the new one, meaning there will be the same 10' cable with a female BNC on the end. There is an interconnect cable between your knotmeter and speed sensor [SX-120]. The interconnect cable consist of a 30' run of coax cable with male BNC connectors on each end. One end mates with your knotmeter, the other end mates with the SX-120. No splicing, adapters or cutting needed. Just disconnect the old one, connect the new one and you are done.
I went to the marine electronic store at the suggestion of the ham radio gentleman, and the folks there said just splice it by un-braiding the outer wire, like the photo below.
It seems easier than buying a once-in-a-lifetime use tool. I think Ken's BOX idea will work.
It's going to be brain-salad-surgery to do this with the wires on the saloon sole.
Stu,
Box: Crimp, solder on terminals and use a term strip, yah mean?
With that waterproof box, it could LIVE in your bilge. :rolling
Were the BNCs you got a crimp, compression, or twist-on? I believe I have seen FM to FM barrel couplings readily available.
Since it's just RG-59 cable as an option I would be tempted to first try using just two F-type Male connectors and a FM- FM barrel coupling between them, instead of the BNCs. And heat shrink it up super waterproof. The F will transpit the singnal same as a BNC will.
Ken
Quote from: KWKloeber on May 12, 2015, 02:04:03 PM
Since it's just RG-59 cable as an option I would be tempted to first try using just two F-type Male connectors and a FM- FM barrel coupling between them, instead of the BNCs. And heat shrink it up super waterproof. The F will transmit the signal same as a BNC will.
That may be a much more attractive situation. I'll see if I can get those from the ham radio store.
Quote from: Stu Jackson on May 12, 2015, 02:33:23 PM
Quote from: KWKloeber on May 12, 2015, 02:04:03 PM
Since it's just RG-59 cable as an option I would be tempted to first try using just two F-type Male connectors and a FM- FM barrel coupling between them, instead of the BNCs. And heat shrink it up super waterproof. The F will transmit the signal same as a BNC will.
That may be a much more attractive situation. I'll see if I can get those from the ham radio store.
That coupling-up, could still be made inside, rather than do away with it, the box. Instead of needing to heat shrunk to moisture-tight it all.
kk
I found a BNC to BNC connector: https://www.youtube.com/watch?v=aoRwPPrY9z8 (https://www.youtube.com/watch?v=aoRwPPrY9z8) See minute 3:45.
There are also twist-on BNC connectors so I don't have to purchase a crimper.
Looks like it's worth getting a stripper instead of trying to strip the insulation back with a box 8cutter - that RG58 is too small for even my tired old eyes to see without a magnifying glass!!!
Quote from: Stu Jackson on May 13, 2015, 11:32:25 AM
I found a BNC to BNC connector: https://www.youtube.com/watch?v=aoRwPPrY9z8 (https://www.youtube.com/watch?v=aoRwPPrY9z8) See minute 3:45.
There are also twist-on BNC connectors so I don't have to purchase a crimper.
Looks like it's worth getting a stripper instead of trying to strip the insulation back with a box cutter - that RG59 is too small for even my tired old eyes to see without a magnifying glass!!!
Here's the coax striper that I use... works fine for the little I do (mostly reran some Time Warner cable at the new house).
http://www.harborfreight.com/rotary-coaxial-cable-stripper-98953.html
And this is the compression tool I use for RG59, RG6. Works perfectly. I bought better seal-tite terminals also.
http://www.harborfreight.com/coaxial-cable-compression-tool-95862.html
I would guess that a "seal-tite" compression type would be better than twist-on, and slightly better than crimp-on, but 'EASY' is worth trying first for sure.
Female - Female couplers are all over eBay and Amazon. RShack also.
http://www.radioshack.com/gold-plated-bnc-female-to-female-coupler/2780119.html#.VVObQflViko
Ken
Thanks, Ken. I'm glad the "real world" (at least YOURS :D :D :D) reflects what I've learned from YouTube. :clap :clap :clap
Like ATM machines, microwave ovens and autopilots, how did we ever live without it? :shock:
Interesting information -- I used those Radio Shack BNC connectors to wire in an A/B switch so I could display Loran or GPS data to a cockpit display.
I also soldered the coax wires and used those "poor quality" RS connectors.
That system preformed flawlessly for only 20+ years, until USCG stopped funding LORAN !!!!!
A thought
Quote from: Stu Jackson on May 13, 2015, 11:32:25 AM
I found a BNC to BNC connector: https://www.youtube.com/watch?v=aoRwPPrY9z8 (https://www.youtube.com/watch?v=aoRwPPrY9z8) See minute 3:45.
There are also twist-on BNC connectors so I don't have to purchase a crimper.
Looks like it's worth getting a stripper instead of trying to strip the insulation back with a box cutter - that RG59 is too small for even my tired old eyes to see without a magnifying glass!!!
PROGRESS UPDATE:
Bought what Amphenol calls "Super Twist" BNC connectors and a BNC "Inline Splice" fitting, so the old female connector on the transducer wire will be replaced by a male with the inline splice fitting between them.
The stripper was a wise investment. DMI nicely got back to me, advised 50 ohm, RG58.
I started on the long 30 foot wire that goes back to the cockpit. Foot by foot, I found the braided wire to be completely compromised --- the water had wicked up through the cable under the insulation, back to at least five feet aft of the mast.
Surprising that the knotmeter worked as long as it had.
I returned to the electronics store (Al Lasher's Electronics in Berkeley - a truly great place out of the 1950's!!!) and the helpful owner suggested that I purchase a pre-made BNC to BNC 12 foot cable, saving me both effort and $ for two more Super Twists, and another inline splice.
Next step is to work my way back to un-compromised braid on the long wire going aft and then do the same for the wire forward to the transducer. If I need more, I know I can get either 6 or 12 foot BNC to BNC pre-made extensions.
Great store, great help (nice to have someone who knows their business to suggest something you didn't even ask for or know existed that saves both time & $$$-how quaint! :clap :clap :clap). Also many thanks to a few skippers on co.com who helped me understand the possibilities and materials available.
More to follow. Glad I don't have to splice this stuff, it's TINY. :D :D :D
Pictures at eleven! :clap
Complete success. Knotmeter works. Tech Notes written for next issue of Mainsheet.
Quote from: Stu Jackson on June 30, 2015, 11:28:55 AM
Complete success. Knotmeter works. Tech Notes written for next issue of Mainsheet.
do you have a pic of a finished terminal?
k
Not a finished one, but here are the parts:
cool thanks Stu, looks easy enough to use :clap
And these are screw on- not crimp, correct?
Hopefully they won't end up in the bilge again :rolling
Are you HST-ing them, for a moisture guard?
k
The picture showed the new screw on (called Twist On by Amphenol) with a BNC to BNC connector. Old transducer wire >>> new twist on >>> butt connector >>> new premade BNC to BNC patch cord >>> butt connector >>> new twist on >>> old long wire to cockpit.
Yes, the last one's in the bilge, no stopping that geometry, but it is now high up just under the floorboard across from the nav station, instead of where it was in front of the mast and down in the water (yuck!). The forward one is way up in the V berth since I got a looong patch cord.
I have started to shield the new connectors. Started on the bilge one with a thin roll of butyl tape pushed into the lip between the base of the twist on connector and the outer insulation, then wrapped with tape.
Then I'm planning on doing this, thanks to Forest from Mandeville, LA on co.com. I will do it step by step to make sure everything continues to work.
I think Ron Hill's advice to always do one thing at a time so you KNOW where the problem comes from is EXCELLENT.
You can definitely use the butyl tape Maine Sail sells. just wrap it in electrical tape. In fact, that's how RF connectors are typically wrapped for weatherproofing. The butyl, especially the black kind used on connectors, will stick to the connector and can be messy. What many do is first wrap the completed and connected junction in electrical tape, wrap that in butyl, then wrap the butyl in more electrical tape. when done, the cable will look like a snake that has just eaten something. I have seen this hold up in sun/rain for many years. There are other products that would work well and not as messy. I have been using self fusing silicone tape made by 3M and like the properties of it. It doesn't leave any sticky residue and seems to hold up well exposed. I still wrap it with electrical tape on my connections just to protect the soft silicone material.
The jury is still out on whether I'll need to do the one in the V berth, since it'll be out of any water and I can see how it's holding up. I may just do the butyl tape at the joint of the twist on and wrap that in tape. We'll see. After all, the simple BNC connector that was in bilge water for the past 30 years did it for, well, 30 years, right? :D
Details in an upcoming Mainsheet Tech Note, and the Tech Notes Online. :D
TNO is here: http://www.c34.org/mainsheet/html/2015/Knotmeter%20Cable.htm (http://www.c34.org/mainsheet/html/2015/Knotmeter%20Cable.htm)