belden 9913 cable

[osiris]

Hi all,
Where do you all get 9913 cable? I see several places on the web but would rather deal with a known good supplier. I'm getting a 996 Uniden and I want to run good cable to it. (the cable and antenna I have are old.) I'm also, I think, going to get a Diamond Discone. I live in the poconos & I know it is hard to get good reception, but I get quite good( I think ) reception even with my old antenna. Just trying to improve what I can get.
Thanks for any suggestions.
Bob

 

[MB]

I would reccomend The R.F. Connection

http://users.erols.com/rfc/index1.htm

Have have bought a lot of cable off these guys. Great customer service..

I would also suggest a band specific antenna, if you only listen to one frequency range - for best performance.

www.antenex.com

 

[KR4BD]

Almost all the Ham radio outlets will have it (AES, Ham Radio Outlet, R&L, etc.). I have used 9913 for many years and have been very pleased with it. If you are not familiar with it, it is somewhat rigid (heavy) and it takes a little skill to solder on the PL-259 connectors. It lasts forever if water does not get into it (from improperly mounted connectors). I've got some runs of it that are over 20 years old but still look and perform like new.

 

[VernM]

One who specializes in just the wires and connectors/accessories for antennas is www.thewireman.com. I've been a customer of his for many years and never been unhappy with price, quality, or the great help he offers.

 

[AK9R]

In spite of the popularity of Belden 9913, I would recommend against it.

9913 is an air dielectric cable. The inner conductor has a "skin" of polyethylene and that sits inside a larger diameter tube of polyethylene. Outside of that larger diameter tube is the braided shield. Separating the the two tubes of polyethylene is a polyethylene spiral "rope" that maintains the separation between the inner conductor and the shield.

The problem with all of this is that any moisture or water vapor that gets into the air gap will eventually condense into water that collects in a low spot in your cable run. That changes the characteristics of the cable. Since PL-259 connectors are not waterproof by design, you are almost guaranteed to get moisture in your 9913 over time. There's no way for the average hobbyist to get all of the moisture completely out of the cable.

As an alternative, I recommend a closed-cell foam dielectric cable such as Times Microwave LMR-400. It has equivalent performance to 9913 without the problems. Also, The Wireman has a foam dielectric low-loss coax of his own design.

Of course, you have to be careful attaching PL-259's to foam dielectric coax. Too much heat and you melt the foam.

Also, if your coax is going to see any kind of movement, look for the stranded center conductor varieties of these cables. They are more flexible than the ones with solid center conductors, though you do generally give up some signal with the stranded conductors.

Bob...

 

[MB]

In spite of the popularity of Belden 9913, I would recommend against it.

9913 is an air dielectric cable. The inner conductor has a "skin" of polyethylene and that sits inside a larger diameter tube of polyethylene. Outside of that larger diameter tube is the braided shield. Separating the the two tubes of polyethylene is a polyethylene spiral "rope" that maintains the separation between the inner conductor and the shield.

The problem with all of this is that any moisture or water vapor that gets into the air gap will eventually condense into water that collects in a low spot in your cable run. That changes the characteristics of the cable. Since PL-259 connectors are not waterproof by design, you are almost guaranteed to get moisture in your 9913 over time. There's no way for the average hobbyist to get all of the moisture completely out of the cable.

As an alternative, I recommend a closed-cell foam dielectric cable such as Times Microwave LMR-400. It has equivalent performance to 9913 without the problems. Also, The Wireman has a foam dielectric low-loss coax of his own design.

Of course, you have to be careful attaching PL-259's to foam dielectric coax. Too much heat and you melt the foam.

Also, if your coax is going to see any kind of movement, look for the stranded center conductor varieties of these cables. They are more flexible than the ones with solid center conductors, though you do generally give up some signal with the stranded conductors.

Bob...

Interesting.

However, even if it did have an air dielectric, if you are using N connectors and the end is sealed really tight with coax seal you should be all set.

Don't know what kind of Belden 9913 are you giving the specs for, but the Belden 9913 I use has a high density foam dielectric.

Belden 9913F7 I am using says that it is 7 strands Stranded Cu center conductor with high density, FOAM DIELECTRIC (not air).

 

[AK9R]

However, even if it did have an air dielectric, if you are using N connectors and the end is sealed really tight with coax seal you should be all set.

Yes.

Depending on the humidity at the time the connectors are put on the cable and the length of time the cable had been left open to the atmosphere, you could come out all right. A piece of 9913 that's been sitting around unterminated during humid summer months may have some internal condensation when the weather turns cold in the winter.

Don't know what kind of Belden 9913 are you giving the specs for, but the Belden 9913 I use has a high density foam dielectric.

As you stated, you aren't using 9913, you are using 9913F7. Both varieties are in the Belden catalog and they are very different cables. Also note that the attenuation at high frequencies for 9913F7 is worse than 9913.

Bob...

 

[traumacop]

I would recommend LMR-400 also. Here is a link to a page with different coax. At the bottom is a loss chart. Not a huge difference, but with the price difference, LMR comes out on top. I have been using it for some time now.

Don't worry about soldering the connectors or how rigid the coax is. Order it with the connectors on and get a 3 foot jumper of something flexible to connect to the rig.

Also, don't use a length any longer than you need. The more coax the more loss.

http://www.universal-radio.com/catalog/cable/coax.html

Good luck.

 

[MB]

Yes.

Depending on the humidity at the time the connectors are put on the cable and the length of time the cable had been left open to the atmosphere, you could come out all right. A piece of 9913 that's been sitting around unterminated during humid summer months may have some internal condensation when the weather turns cold in the winter.


As you stated, you aren't using 9913, you are using 9913F7. Both varieties are in the Belden catalog and they are very different cables. Also note that the attenuation at high frequencies for 9913F7 is worse than 9913.

Bob...

Oh, I see... My bad, your right.

What about 9913FX from Cable X-Perts? It says it has a Semi Solid Polyethylene dielectric.. how is water intrusion with that?

 

[AK9R]

"Semi Solid Polyethylene dielectric" sounds like Belden 9913, but I can't find 9913FX on Cable X-Perts web site.

traumacop makes an interesting point. Buy cable from a reputable company that will sell you a cable assembled to your specifications. They should have the tools, skills, and experience to properly attach the connectors. You can then use short jumpers to deal with rigid cables or imperfect lengths. However, those jumpers mean more connectors which means more possibilities for signal attenuation, impedance mis-match, or mechanical failure.

Tread carefully in the coaxial cable market. Belden, Times Microwave, and Andrew are respected brands and the quality of their products is generally consistently high. The Wireman also has a good repuation in the amateur radio market and they private label some of their products. On the other hand, there are shady dealers selling coax just as there are in any other market. Let the buyer beware.

Bob...

 

[MB]

"Semi Solid Polyethylene dielectric" sounds like Belden 9913, but I can't find 9913FX on Cable X-Perts web site.

I bought the cabel back in 2002, and it is in the catalog I have from back then. Must be they don't make it anymore. The cable also says that it is direct burial.

How long should cable last?

Maybe I should replace it with some LMR-400 or LMR-400UF.

What do you think?

 

[RISC777]

You pay more for UF (UltraFlex) for its flexibility. If you've got a turn or bend or two, and depending on how much 'bending' you need to do in routing it, the UF may be worth the extra cost. Don't pay more than $0.65 per foot on the LMR-400, though (non-UF and not counting termination and connectors). [If you're going through walls, like in a house, they also make Plenum and other fire retardant variations.]

 

[MB]

You pay more for UF (UltraFlex) for its flexibility. If you've got a turn or bend or two, and depending on how much 'bending' you need to do in routing it, the UF may be worth the extra cost. Don't pay more than $0.65 per foot on the LMR-400, though (non-UF and not counting termination and connectors). [If you're going through walls, like in a house, they also make Plenum and other fire retardant variations.]

I can get the LMR-400 for .58 per foot. I will have only two bends to make (one bend to enter the basement and another bend to come up through the floor). Will I be able to make these bends with the LMR-400?

 

[Hoofy]

It would depend on how tight the radius is. I think the LMR-400 rigid requires a 12inch radius. Check the specs on it and it will give you the info on bending.

 

[trimmerj]

on a related note, I have a single run of 9913 going to a Log Periodic on a rotor. Big loop to allow for movement with the rotor, but have always had a concern that spinning the antenna would end up damaging the cable. Should I do a flexible jumper ? The antenna is used primarily for mil-air and UHF.

 

[RISC777]

I can get the LMR-400 for .58 per foot. I will have only two bends to make (one bend to enter the basement and another bend to come up through the floor). Will I be able to make these bends with the LMR-400?

I was shocked. Times Microwave states 1" bend radius. Me? I'd never bend it one inch, regardless of their warranty(ies). I've made a bend of between 4 to 5 inches without worrying and no damage myself. The only thing to do when bending is mind the stress from pushing or pulling on the cable due it's rating of 10 percent max stretching of the center core. Similar to higher is better and shorter the cable run the better, the less bending and less bend radius the better.

`Doug

 

[kb2vxa]

Hi all,

Dispite the nay sayer's comments I have never had ANY moisture problems with ANY coax installation including Belden 9913. Quite a few years of painstaking research has gone into my use and recomendations that it gives the best bang for the buck out of all the commonly available cables, hard line excluded of course. I have done the math needed to calculate signal loss in any given run at any given frequency, there's a lot more to it than the dielectric K, there is propagation velocity to consider as well as several other factors.

Sorry RXR for your unfortunate experience with improperly sealed connectors. ANY coax will suffer from moisture ingress and propagation along the braid by capilary action, the cable doesn't have to fill with water for it to suffer. For that to happen you'd have to pump steam into it, a small bit of humidity won't get far unless nearly all the air is displaced. Oh I expect your usual dispute but that's how I see it based on my good experience with it over all these years.

Now as to where you can get genuine BELDEN 9913 which is BTW a unique cable with a proprietary part number, it looks like Wireman may be the only source for the real deal. I'll have to check into that myself, every other supplier seems to offer only some sort of foam dielectric cable, a "9913 type" more resembling RG-8AU than anything else. I suppose he'd answer an e-mail inquiry, I'm not about to travel to Gaithersburg MD just to see him again, he doesn't come this far north to the local hamfests.

Well, if push comes to shove I'll have to order a spool from Belden, I'll accept no substitutes nor am I about to feed Times Microwave or Andrew unless I'm buying hard line or Spiroline, Andrew's trademarked large diameter version of 9913 which requires those pesky flange connectors. Then again I'm not installing an FM broadcast antenna so forget the Spiroline. (;->)