Coax source, perferably cusom?

[Gene Neill]

I've been studying this article by the great Maine Sail: https://pbase.com/mainecruising/vhf_cable&page=1

I like the looks of this method, and I'm confident I can do it. So I can forgo the "cusom" cable, if I can find quality crimp/solder connectors in the appropriate size. So far the only ones I've found are from DX Engineering ... anyone familiar with them? https://www.dxengineering.com/parts/dxe-pl259cs8x-6?seid=dxese1&gclid=Cj0KCQiAoab_BRCxARIsANMx4S65mU 42oEn5ztgQ0uSB8NaZZJD8CTmzMIUjKGEw_0C2tmgg7eQPrKAa Al34EALw_wcB

I'm not thrilled that the country of origin is not specified.

[S/V Illusion]

Originally Posted by Gene Neill

I've been studying this article by the great Maine Sail: https://pbase.com/mainecruising/vhf_cable&page=1

I like the looks of this method, and I'm confident I can do it. So I can forgo the "cusom" cable, if I can find quality crimp/solder connectors in the appropriate size. So far the only ones I've found are from DX Engineering ... anyone familiar with them? https://www.dxengineering.com/parts/dxe-pl259cs8x-6?seid=dxese1&gclid=Cj0KCQiAoab_BRCxARIsANMx4S65mU 42oEn5ztgQ0uSB8NaZZJD8CTmzMIUjKGEw_0C2tmgg7eQPrKAa Al34EALw_wcB

I'm not thrilled that the country of origin is not specified.

The US Patent number designation implies point of origin. Regardless, they sell only quality silver plated connectors so you can’t go wrong unless you use the wrong crimping tool or wrong size soldering iron. As with all connections, weather tight is essential so seal them properly.

[Jammer]

Originally Posted by jmschmidt

What is a "cusom cable?

A custom coaxial cable is one manufactured of a specific material, made to a specific length, with a specific termination on each end chosen by the buyer. They are in contrast to stock cables that are available in standard lengths in the most common termination types.


If the difference between a cusom-cable and a custom-cable is, in your view, a remarkable matter, there is a description of the difference available here.

[Jammer]

Originally Posted by Gene Neill

So far the only ones I've found are from DX Engineering ... anyone familiar with them? https://www.dxengineering.com/parts/dxe-pl259cs8x-6?seid=dxese1&gclid=Cj0KCQiAoab_BRCxARIsANMx4S65mU 42oEn5ztgQ0uSB8NaZZJD8CTmzMIUjKGEw_0C2tmgg7eQPrKAa Al34EALw_wcB

I have a bin of them in my connector drawer. They work great. You need a soldering iron, a crimp tool of the proper size, and the skills to use them. I use them where I have to i.e. the connection to the radio itself, since VHF radios have SO-239 connectors on them.


In other situations, where I have a choice, I use either an N connector or an SMA connector.


If you are new to soldering and do not have a mentor who is a past master then you really are better off getting the cables terminated by the manufacturer. If the connector won't fit through whatever holes you have to fish it through, use a smaller connector, such as SMA, and an adapter. At the base of the mast if you are adding a connector use type N rather than PL-259/SO-239 as it is more reliable and easier to install.

I'm not thrilled that the country of origin is not specified.

If you're trying to change the world through your buying habits then the $3 you spend for a coax connector isn't going to do it


If you're looking for products that are well made look to the seller. All countries including the USA, China, Mexico, etc etc have widely varying levels of quality in their manufacturing output. Whoever is dealing with the factory gets the quality and precision they are paying for. Throughout history, all countries except maybe Switzerland have been viewed as a low-cost manufacturing center at some point. The AMC Gremlin and the Ford Pinto were both made in the USA. Substantially all iPhones are made in China.

[Spot]

Has there been a discussion related to how to cable and join for stepping and unstepping the mast? Assuming majority of coax is in mast and a tail on each end coming out of the mast. PL259 up top and PL259 at the VHF. What sort of connectors at the mast step? Grommets on the mast and a cable gland to the deck? Not telling but asking- looking to do similar someday.

So buy 1 size too long, cut a piece for the mast, a piece for inside, run, trim, connectors, and viola...?

[Be Free]

Originally Posted by S/V Illusion

You are confusing power with attenuation. There are a myriad of coax loss calculators on line from which you can calculate actual power loss which is a function of power input.

Saying simply that it’s 1watt is nonsense.

A 3 dB loss for example, which is the actual loss in a 50 ft run of cheap small coax at VHF, equates to a 50% reduction of power at the antenna.

I was assuming a 25W input. I thought it would make more sense to him as a power loss than a dB loss.

[Jammer]

1) use waterproof connectors at the base of the mast. N are waterproof, rugged, and readily available but there are other good choices too


2) The most durable solution is to have a bulkhead connector on the mast, and a bulkhead connector on the deck (ideally oriented sideways rather than straight up), and a short jumper between them that can be disconnected at both ends. That way the permanent cabling never flexes, and if someone trips over the jumper you can just replace it with a spare in less time than it takes to figure out there's a problem.


3) A bulkhead fitting through the mast and a pigtail coming up through a deck gland or grommet will work OK but when something happens to the cable you have to fish a new one. If you are a believer in lightning protection, the bulkhead fitting in the mast can be replaced with a polyphaser.

[Jammer]

Originally Posted by Be Free

I was assuming a 25W input. I thought it would make more sense to him as a power loss than a dB loss.

"For every complex problem, there is a solution that is clear, simple, and ...." -- H.L. Mencken


The only way you'll lose a watt or less out of 25, on a sailboat feedline to the top of the mast, is if you run 1.25" Heliax. Even then it will be close.

[Be Free]

Originally Posted by Be Free

The difference between RG8X and RG58 is that RG8X is about .05" larger in diameter and costs about 2.5x more. The difference in power at the antennae at marine VHF frequencies and 48' run is about 1 watt.


RG213 is the "best" with ~3W more power to the antennae over RG8X but it costs 50% more and is almost twice the diameter. Probably overkill for a small sailboat.


For this application I'd go with RG8X.

All assume 25W input, 1:1 SWR, 165Mhz, and 48' run.
RG58 1.253dB 18.732w
RG8X 1.1dB 19.407w (a difference of about 1W)
RG213 .699dB 21.283w (about 3W more than RG58, not RG8X - my bad)



The point I was trying to make is that for his application there is not a lot of benefit in installing the best cable. The middle choice (RG8X) is probably the best choice for ease of installation, cost, and performance.

[Spot]

Originally Posted by Jammer

1) use waterproof connectors at the base of the mast. N are waterproof, rugged, and readily available but there are other good choices too


2) The most durable solution is to have a bulkhead connector on the mast, and a bulkhead connector on the deck (ideally oriented sideways rather than straight up), and a short jumper between them that can be disconnected at both ends. That way the permanent cabling never flexes, and if someone trips over the jumper you can just replace it with a spare in less time than it takes to figure out there's a problem.


3) A bulkhead fitting through the mast and a pigtail coming up through a deck gland or grommet will work OK but when something happens to the cable you have to fish a new one. If you are a believer in lightning protection, the bulkhead fitting in the mast can be replaced with a polyphaser.

Thanks. Two permanent bulkheads and a short replaceable jumper between them makes sense.

[Jammer]

Originally Posted by Be Free

The point I was trying to make is that for his application there is not a lot of benefit in installing the best cable. The middle choice (RG8X) is probably the best choice for ease of installation, cost, and performance.

The problem with RG8X is that it is foam core, which means that it can absorb water and that it is more susceptible to damage from tight bends, particularly if it gets hot. It is also particularly difficult to solder (the foam dielectric tends to collapse) making it a poor choice if you plan to solder PL-259s in place. But it's cheap, it's lightweight, it's good for temporary or noncritical applications that involve longer runs.


There is more to coax than loss.


The standard choices on a boat are RG58 and RG213. These both have a solid polyethylene dielectric and a single copper braid shield. The shield and braid on RG58 is silver plated. While no feedline lasts forever in the real world, particularly when exposed to weather, these will give good reliability over a reasonably long service life.


At 50', the choice of which to use would be determined by the goals of the installation. If the best possible performance under demanding conditions is the goal, use RG213.

[Be Free]

I had not considered the foam core. I concede that RG58 would be a better choice for him.

[Brian.D]

As long as the user does not exceed the recommended bend radius, then just about any of the 50Ω .25"Ø cable should work, given nominal attenuation of the cable at frequency, and SWR at the feed point of the antenna. Again, the key is the bend radius.

[Gene Neill]

Originally Posted by Brian.D

As long as the user does not exceed the recommended bend radius, then just about any of the 50Ω .25"Ø cable should work, given nominal attenuation of the cable at frequency, and SWR at the feed point of the antenna. Again, the key is the bend radius.

I placed an order with DX Engineering last night. Flexibility was a key (THE key, really) consideration. I decided on LMR-240UF, which has a bend radius of 2.5".