Joining RG-8X co-ax

[JayBee]

Regrettably its not always possible to re-route the cable all the way to the radio whenever you lower the mast. On our boat it would be totally impractical.

Same here.

An alternative to PL259's and an inline connector would be solder on type BNC connectors. RF wise they are vastly superior to PL259s and you can get inline male and female so you wouldn't need an inline back to back between two plugs. They are slightly fiddly to fit, but with patience and a steady hand and a set of instructions that you follow TO THE LETTER regarding measurements of how much wire to strip etc at each stage they are not too bad.

BNC m/f crimp connectors are the ones I am trying to source, see first and subsequent posts. I have used these in the past and believe that properly made crimp connections are superior to the soldered option, both for integrity and ease of use - provided the correct ratchet crimper is used and the co-ax is stripped as you describe. There are probably those who will disagree, but IIRC US military specs, at least, call for crimps rather than solder in these types of applications.

I will probably end up buying these connectors direct from the USA, as was suggested earlier.

Thanks for all the input from everyone, so far.

 

[john_morris_uk]

Yes I know you were trying to source BNC Crimp - I was just pointing out that you can get solder on type and it would solve your sourcing problem as they are readily available. Bear in mind that the quality is variable and that cheap is NOT always the best. The best ones are silver plated... They are only a £ or two more than the cheapest.

 

[st599]

Have you tried Martin Lynch or Nevada Radio?

May have better luck there.

 

[ProDave]

As I think someone already mentioned:

Forget PL259's. They are horrible connectors and especially horrible to fit (properly) to RG8. They are absolutely not watertight in any shape or form and for use inside only.

Instead use N type connectors. They are available as an in line plug and an in line socket for RG8. The outer is terminated by way of a clamp, and the inner is soldered or crimped depending on which type you buy.

The mating surfaces and the cable clamp have rubber gaskets so they are to some extent water resistant, though I would still not use them
outdoors without some other protection.

On my boat I have an N type socket as a through deck (cabin top) mount and the cable emerging from the mast has an N type plug and a boot to keep the water out.

More expensive than PL259.s but oh so much better.

EDIT:

Not THAT much more expensive :

http://www.ebay.co.uk/itm/Nickel-N-...munication_Radio_Antennas&hash=item3379be8d81

http://www.ebay.co.uk/itm/N-female-...on_Coax_Cables_Connectors&hash=item4aaac51001

 

[rjcoles]

The solution to this problem is produced by Shakespear pn PL-259-8x-G, its a gold plated 50 ohm joiner that only requires the RG8X cable to be cut cleanly at 90 degrees and then the parts assembled. These parts are on EBay have a look at.

http://www.ebay.co.uk/itm/Gold-plat...tingGoods_FishingAcces_RL&hash=item20cd740497

 

[JayBee]

Forget PL259's. They are horrible connectors and especially horrible to fit (properly) to RG8. They are absolutely not watertight in any shape or form and fur use inside only.

Well, RG8 and RG8X are two very different co-ax cables, but there seems there is a broad consensus in agreement with the horrible nature of PL259s. Yesterday's technology? It is interesting that the highly rated Metz VHF antennae use PL259s as their primary connection to the co-ax - and this at the masthead on most boats. The only waterproofing solution is to wrap the connector in some rather expensive self amalgamating tape.

The N-type connectors look interesting. I will check them out - thanks.

 

[ProDave]

Well, RG8 and RG8X are two very different co-ax cables, but there seems there is a broad consensus in agreement with the horrible nature of PL259s. Yesterday's technology? It is interesting that the highly rated Metz VHF antennae use PL259s as their primary connection to the co-ax - and this at the masthead on most boats. The only waterproofing solution is to wrap the connector in some rather expensive self amalgamating tape.

The N-type connectors look interesting. I will check them out - thanks.

Obviously choose the correct N type connector to match your cable. I posted those examples to show they need not be that expensive and to show those that have never seen them, what an N type plug and socket look like.

Any permanent outside joint that you don't expect to be undoing regularly should be wrapped in self amalgamating tape regardless of what type of connector you use, and it's not particularly expensive, this roll will last you years and do hundreds of joints http://www.ebay.co.uk/itm/Professio...?pt=UK_Sound_Vision_Other&hash=item588bfd062e

 

[JayBee]

The solution to this problem is produced by Shakespear pn PL-259-8x-G, its a gold plated 50 ohm joiner that only requires the RG8X cable to be cut cleanly at 90 degrees and then the parts assembled. These parts are on EBay have a look at.

http://www.ebay.co.uk/itm/Gold-plat...tingGoods_FishingAcces_RL&hash=item20cd740497

Thanks again, but I have just downloaded the instructions and see that I would be back to soldering PL259 connectors!

http://shakespeare-marine.com/pdf/pl-259-8x.pdf

 

[JayBee]

Any permanent outside joint that you don't expect to be undoing regularly should be wrapped in self amalgamating tape regardless of what type of connector you use, and it's not particularly expensive, this roll will last you years and do hundreds of joints http://www.ebay.co.uk/itm/Professio...?pt=UK_Sound_Vision_Other&hash=item588bfd062e

Fair point. I was thinking of the tape offered for sale alongside the Metz antenna.
Probably a very superior product.

 

[ProDave]

Okay I should have read the thread properly.

I read it as RG8 (the large stuff) and did wonder why you wanted to use that on a boat.

So now I realise it's RG8X, much smaller.

So my advice is still avoid PL259,s, but to use BNC plugs and sockets, which have all the aforementioned advantages of N types in being easy to terminate and having rubber seals on the cable entry and mating face, but they are just a lot smaller.

 

[JayBee]

Okay I should have read the thread properly.......

So my advice is still avoid PL259,s, but to use BNC plugs and sockets, which have all the aforementioned advantages of N types in being easy to terminate and having rubber seals on the cable entry and mating face, but they are just a lot smaller.

Dave, that has been my declared intention since post #1.

 

[Salty John]

I feel I must come to the defense of the PL259 connector! They've been around a very long time, it's true, but they are still widely used. Every marine VHF radio has an SO239 socket to accept an antenna cable fitted with a PL259. So you have no choice but to have a PL259 at one end of the cable.

Most good quality antennas have an SO239 socket to accept a PL259. Yes, some have an N connector, some a factory crimped cable and some a proprietary RG58 'strip and stick in the hole' type connector. The PL259 is by far the most common connector because it does the job and has the mechanical integrity needed to handle the vibration and violent movement that an antenna cable is subjected to.

All external connections should be protected with self amalgamating tape, preferable silicone compression tape.

If you fit a PL259 to RG8X and the PL259 has the correct adapter, the adapter provides an extremely strong mechanical joint to the cable braid. You do need to solder the centre core and this can be a bit daunting if you haven't done it before but it really isn't that difficult. I agree they can be tough to fit in an awkward location where you can't hold the PL259 in a vice with the pin vertical to allow the solder to flow, so you need to think about that when planning the cable route and joint location.
Or, as has been suggested, use a crimped connector. The problem is the cost of the crimping tool for a one-off use. The Shakespeare connector mentioned earlier is another way.

I know that the BNC is popular because of its slim design but remember it is a quick connector, designed for situations where cables are frequently moved, rather than a secure connector - there can be vibration issues with BNC connectors. That's why the TNC, the threaded version of the BNC, was introduced. But if your going to use a TNC pair you might as well use two PL259s and a barrel connector.

I think the PL259 does the job for which it was designed and does it very well - if it didn't it wouldn't still be with us.

 

[temptress]

use BNC connectors. Not been looking for this sort of stuff in the Uk for a while but if I were I would look in Maplins or RS components. Assuming they are still going (I get the impression that the whole of the Uk is closing down) you should find what you want.

Joining co-ax cable is not hard - just make sure the cores join cleanly and the shield is continuous...

 

[JayBee]

Hello John, I wondered where you were!

".....The problem is the cost of the crimping tool for a one-off use...."

This looks like the ratchet crimper I own, good for many different co-ax cables and connectors and only £8.95, with free delivery:

http://www.amazon.co.uk/Crimp-Coaxi...GB8Q/ref=sr_1_2?ie=UTF8&qid=1359188951&sr=8-2

No doubt the PL259 is a pretty rugged connector, but efficient soldering is not that easy to achieve, judging from much info I have uncovered in my internet searches. There is also the issue of its bulkiness and passing this though relatively narrow conduit or cable glands.

Cheers

JB

 

[rjcoles]

Thanks again, but I have just downloaded the instructions and see that I would be back to soldering PL259 connectors!

http://shakespeare-marine.com/pdf/pl-259-8x.pdf

These Shakespeare in-line connectors do not need any soldering!!! You just cut the cable at 90 degrees making sure that there are no whiskers from the shield, put the looking nut over the cable, push the cable fully into the in-line connector, close down the four tangs that grip the shield and tighen the nut. Repeat at the other end and you have a perfect easy connection (well it only has a very small loss). You only need the solder or crimped connections for the ariel or VHF.

You can alsotake this joint apart with care, undo the nut, lift back the tangs and pull the cable out!

 

[lw395]

Whatever you use, it is a good idea to use something that seals the coax against moisture ingress.
Clamp type connectors, where a soft rubber sleeve acts as a gasket are often superior to crimps.
There is no point having low loss cable and allowing the braid to corrode, as even light tarnishing pushes the loss up significantly.
The cheap PL259's are about the worst connectors on the market in this respect. Possibly challenged by the cheap F connectors used for satellite TV.

 

[rob2]

So you have no choice but to have a PL259 at one end of the cable.

Well, not necessarily on the cable. I used to have a H/H with a bnc stubby aerial. To allow everything to interchange, I used an adaptor on the Fixed VHF and crimped a bnc onto both the main aerial and the emergency aerial (home-made Slim Jim). Didn't have RG8X cable size, though.

Rob.

 

[JayBee]

These Shakespeare in-line connectors do not need any soldering!!! You just cut the cable at 90 degrees making sure that there are no whiskers from the shield, put the looking nut over the cable, push the cable fully into the in-line connector, close down the four tangs that grip the shield and tighen the nut. Repeat at the other end and you have a perfect easy connection (well it only has a very small loss). You only need the solder or crimped connections for the ariel or VHF.

You can alsotake this joint apart with care, undo the nut, lift back the tangs and pull the cable out!

Yes, just got back to this thread and have found the Shakepeare in-line connector now. I copied your part number into a search engine and got the wrong item.

This looks good, at least as a temporary measure.

Thanks to you and to all other respondents - the search for RG8X BNC crimp connectors goes on!

 

[Boo2]

Would it be possible to install a bulkhead connector onto/into the mast and conect to that with jack plugs ?

Boo2

 

[misterg]

the search for RG8X BNC crimp connectors goes on!

Keep an eye on ebay - I could find BNC crimp connectors but not solder-on for RG8X when I was looking last October (for exactly the same reasons). Can't seem to find them again at the moment though I didn't realise that a crimp tool could be had so cheaply (I thought they were ~£100+), so thanks for that.

I'm going to defer the problem until the mast comes down by installing the cable in one piece with a slack loop under the headlining where it comes through the deck.