Discount Coax. Is it worth the savings?

[Realtor MA]

Any of you hams have experience with some of the off brand coax? I need to buy about 300 feet and the savings would be fairly substantial. A few months ago I heard about a company called Jefa Tech. They make a LMR400 Flex clone that will save me about 40 cents a foot. OTOH if it sucks I won't be saving anything.

 

[MACGYVR]

The fake coax is crap. In short runs its ok but long runs will give problems. Things like poor dielectric, not a 100% braid, no foil etc. Usually CCA (copper coated aluminum) rather than solid copper.

 

[rep308]

Where are you located? You Do It Electronics in Needham is the best source for quality, low cost gear like this. Heck, they even still wear pocket protectors there!

 

[n1oty]

Always put good coax up. Once a signal is attenuated in a piece of crap, it is gone and cannot be recovered. I will also respectfully disagree with the comment about You-Do-It. While I agree that they have some good quality coax, you'll pay through the nose for it. I've found you can buy brand new Andrews FSJ4 or LDF4 on ebay for about the same price as You-Do-It sells RG-8, and there is a world of difference between RG-8 and LDF4!!! The importance of high grade coax and connectors goes up as you go up in frequency. 2 Meters is not too hard on coax, but frequencies above that make tougher demands on the coax. I've witnessed cheap, small coax melt at 900 mhz.

 

[cockpitbob]

Save once. Suffer for a lifetime.

 

[Realtor MA]

You do it is a great store but there coax is high. The cheapest I could find so far for LMR400 is 79 cents at Texas Towers. The flex is about $1.29.
Looks like I'll be handing over the $$ for the good stuff

 

[imstuner]

www.monoprice.com

Recommend in av forums


Sent from my iPhone using Tapatalk

 

[n1oty]

What is the highest frequency that you contemplate transmitting or receiving on this coax???

You do it is a great store but there coax is high. The cheapest I could find so far for LMR400 is 79 cents at Texas Towers. The flex is about $1.29.
Looks like I'll be handing over the $$ for the good stuff

 

[Realtor MA]

I'm going to have two runs tot he tower. One for HF (1.8-30mhz) and another for 2meter/70cm

ETA. I ordered Belden 9913f7 from Davis RF for 90 cents a foot

 

[drgrant]

9913F isn't bad stuff, if you are trying to go on a budget. I'd rather buy Belden 9913F than "fake" LMR-400.

-Mike

 

[Realtor MA]

Is the real LMR 400 that much better? I figured it was somewhat comparable for the HF work.

 

[n1oty]

I am not a fan of using any significant lengths of Belden 9913 and it's variants. Losses in 9913F are barely tolerable for HF, become noticeable at VHF and start to wreak havoc at UHF. At 440 mhz, 9913F losses are just over 3 dB per 100 feet. The net effect is that your transmit and receive strength will be cut in half. If UHF work is contemplated, I would suggest nothing less that Andrew FSJ4 or LDF4 which is generally available on ebay for around a $1 per foot. A ten percent premium over what you paid would have given you dramatically better coax with much lower loss and much higher power handling capability.

I'm going to have two runs tot he tower. One for HF (1.8-30mhz) and another for 2meter/70cm

ETA. I ordered Belden 9913f7 from Davis RF for 90 cents a foot

 

[Realtor MA]

Uggh. I hope I wasn't looking at bogus numbers. The attenuation figures I found for the Andrew FSJ4 were only about 2.1 db per 100 feet at 400 mhz compared to the belden which was 2.8. Because my current plan includes only very limited use of UHF(ie playing with some satellites) I figured I would be ok with the belden. The best price I could find on the Andrew was about 45 cents more per foot when I factored in shipping.

I am not a fan of using any significant lengths of Belden 9913 and it's variants. Losses in 9913F are barely tolerable for HF, become noticeable at VHF and start to wreak havoc at UHF. At 440 mhz, 9913F losses are just over 3 dB per 100 feet. The net effect is that your transmit and receive strength will be cut in half. If UHF work is contemplated, I would suggest nothing less that Andrew FSJ4 or LDF4 which is generally available on ebay for around a $1 per foot. A ten percent premium over what you paid would have given you dramatically better coax with much lower loss and much higher power handling capability.

 

[n1oty]

I think you'll find the actual loss figure for 9913F to be a pinch more than that, but close enough for our purposes. When comparing FSJ4 and LDF4, LDF4 has significantly lower loss and is typically found for about $1.10 to $1.20 per foot shipped from places on ebay. Even better deals can be found on Andrew HS4RP, which is a plenum rated version of LDF4, but with an air dielectric. I've bought hundreds of feet of HS4RP for no more than 50 cents a foot and it yields a 2 dB loss at 440 mhz. That is at least 1 dB better than your Belden and at a significantly cheaper price.

I also favor Andrew over other coax because it can be grounded much better, due to it's SOLID COPPER outer sheath, rather than cheap braids and/or tin foil. That is assuming, of course, that you would want a solid installation.

 

[Realtor MA]

I have a lot to learn. At some point I'll replace the Belden.

 

[n1oty]

Don't get rid of it. Simply use it for short jumpers and HF coax. I guess my point is to just point out that some incredible bargains can be found on really high quality coax, if you are willing to make an effort. For example, I have purchased brand new LDF5 (7/8 inch Andrew) in 100 foot sections for as little as $1.50 per foot delivered. You don't want to know how cheaply I purchased a 765 foot spool of LDF7 (1 5/8 inch Andrew) delivered. You'll cry. Nobody was interested in it. The local guys I know said the fittings would cost too much. So, after acquiring the LDF7, I proceeded to acquire DIN connectors for $3 a piece and N connectors for as little as $15. Go check the minimal loss figures for LDF5 and LDF7.

I have a lot to learn. At some point I'll replace the Belden.