TXM Super Flex 1/2" Cable - FSJ4-50B

[Flameout]

I'd like to eliminate my 2-25' sections of coax (One section is Andrew Heliax LDF4-50a and the other Andrew Heliax FSJ4-50b connected with good N connectors) and searching, I came across the TXM cable, which I have never heard of. The specs are about identical to the Andrew FSJ4-50b but a lot less money so I was wondering if anyone here has used or is currently using it on their repeater setup, and how it's working out.

https://www.txmstore.com/1-2-super-flexible-50-ohm-coax-cable-per-foot-compare-to-commscope-fsj4-50b-spf12/

It will feed my Commscope DB404 from my Motorola Radius GR500 repeater

[SteveShannon]

31 minutes ago, WRYZ926 said:

One of the differences between coax quality is the amount of braided shielding. Higher quality coax will have more/thicker braids.

Here is what the braided shield looks like on quality LMR400 Ultraflex.

Another difference in the construction of coax shielding is the material used in each layer of shielding.  Some companies use copper braid over aluminum foil.  Others use copper braid over copper foil.  

Both aluminum and copper are good conductors, with copper being better (silver is the best elemental conductor). Both oxidize.  Aluminum oxide is a poor conductor (aka good insulator). Copper oxide doesn’t affect conductivity much.

Some people who work with repeaters claim that using a cable that has copper over aluminum causes issues when used on repeaters because that aluminum oxide layer forms a semiconductor.  

[Flameout]

Well, I just ordered 50', so since no one here has ever used it, I'll try to post my review of it after I get it installed

[SteveShannon]

54 minutes ago, Flameout said:

Well, I just ordered 50', so since no one here has ever used it, I'll try to post my review of it after I get it installed

Installation is usually the most difficult part.  I would wring it out on an antenna analyzer or network analyzer first.

[gortex2]

I only use CommScope FSJ. Also just started using Eupen cable. The EC4-50-HF appears to be very similar. I have run some tests with CommScope connector on the EC4-50HF and so far it appears to sweep and work ok. Only issue with eupen is the lack of support from the large companies. Last check neither Tessco or talley carried anything for it. Thats why I stick to CommScope. 

https://eupen.us/products/coaxial-cables/

[Flameout]

After messing around with this coax, I'd recommend to avoid it. It's like the cheap Chinese copper is thinner than the good USA made FSJ4-50B coax. Attaching a connector, it just shredded the copper.I finally got my connectors on and tests are ok, but I'd still never buy it again

[WRYZ926]

That sheath looks like dog doo. It looks to be paper thin so I can see why it peeled back and/or tore on you.

[SteveShannon]

15 hours ago, WRYZ926 said:

That sheath looks like dog doo. It looks to be paper thin so I can see why it peeled back and/or tore on you.

Exactly.  No braid appears to be present, just very thin foil.

[WRYZ926]

One of the differences between coax quality is the amount of braided shielding. Higher quality coax will have more/thicker braids.

Here is what the braided shield looks like on quality LMR400 Ultraflex.

[WRYZ926]

Construction of the coax and materials used definitely makes a difference. Dissimilar metals can cause issues when they corrode/oxidize. I know not radio related, but I always cringe when people don't use any type of anti-seize on steel bolts into aluminum parts that are exposed to the environment such as on vehicles. 

[WRXB215]

1 hour ago, WRYZ926 said:

steel bolts into aluminum

Yep, and zinc and aluminum are a bad mix. I've seen star washers turn into dust. Stainless bolts into aluminum and you get gauling if you don't use some kind of anti-sieze.

[hfd376]

The type of feedline Flameout is referring to does not have a braided outer conductor. How did you prep that cable? Was it done with an all in one prep tool, used with a drill or T handle? If so, was it for that brand and model cable?

[Flameout]

 

5 hours ago, WRYZ926 said:

One of the differences between coax quality is the amount of braided shielding. Higher quality coax will have more/thicker braids.

Here is what the braided shield looks like on quality LMR400 Ultraflex.

 

 

 

I do have some good LMR400 going to my GAP Titan DX HF antenna. I was 'hoping' that this TXM cable would be similar to the Andrew Heliax FSJ4-50b hardline to use on my repeater. I do have some abs industries 25400f on a repeater and it works great. The TXM sure is nothing like this good Andrew Heliax FSJ4

[Flameout]

9 minutes ago, hfd376 said:

The type of feedline Flameout is referring to does not have a braided outer conductor. How did you prep that cable? Was it done with an all in one prep tool, used with a drill or T handle? If so, was it for that brand and model cable?

I used the Commscope MCPT-1412. It did a good job prepping the cable, it's just when I threaded on the N connector, it tore up that cheap copper. I always use good fittings too. Was using an Andrew F4PNMV2-HC

[hfd376]

I have no experience at all with the TMX cable, and this is just a guess on my part. Perhaps the tolerances for the TMX are different than the Commscope. Maybe the piece that goes between the outer conductor and the dielectric in the backnut was too large or small. Again, just a guess.

[WRYZ926]

Always go with the best quality coax you can afford, especially for repeater use and/or long runs. UHF is not as forgiving as VHF or HF frequencies when it comes to coax cable.

[Flameout]

34 minutes ago, hfd376 said:

I have no experience at all with the TMX cable, and this is just a guess on my part. Perhaps the tolerances for the TMX are different than the Commscope. Maybe the piece that goes between the outer conductor and the dielectric in the backnut was too large or small. Again, just a guess.

Before purchasing, I emailed them and asked if my Commscope/Andrew fittings that work on my Commscope fsj4-50b cable would work on theirs, and they assured me their cables were the the same specifications. On this TXM cable, you just have to be damn sure to to thread the fitting too tightly. I got things working and everything tests OK, but I'll stick with good USA made cable from now on

[hfd376]

I checked their website kind of quickly, and I really didn't see where they referenced any type of prepping or a connector to use. I'm glad you got the connectors on and working.