JEFA Tech Blog

Mike asks "I need to replace several runs of Times Microwave LMR-400UF. At the time I bought a 500-ft spool of it, they neglected to publish the fact that it is unsuitable for exposure to sunlight and UV. If we have anything here in Far West Texas, it is sunlight and UV. Additionally, I have 6 runs of coax that need to loop around antenna rotors. The cable must be flexible enough to withstand repeated flexing around the rotors.  How suitable will your cable be in meeting my needs? THANK YOU. Have a SUPER DAY." Answer:Good morning Mike, thanks for...

Question from John: I have a base scanner Uniden SDS200 that I am looking at doing about 75' run to an OmniX base antenna to pick up mainly 800 Mhz frequencies. What cable would you recommend? What ends would I need for the cable? Answer: Hi John, For connectors, the SDS200 has a BNC Female antenna connector.  The OmniX base antenna has an N Female connector.  So your cable will need to be BNC Male to N Male. I have two cable recommendations, LL240FLEX and LL400. The LL240FLEX is a 0.240" diameter cable and has a stranded center conductor which...

Bruce asks:The situation: 1. HF: 35 feet to the hole in the wall of the house, then add 5 more to the radio.2. 2m/440: 41 feet to the hole in the wall, and 5 more to the radio.Which is best RG-213/U or LL400?  The LL400 you have appears less loss than 213 and is slightly less, which surprised me. Also it seems that against everything I have read online that 400 is very stiff, it has a better bending radius than the 213 you carry. So your recommendation?I prefer putting on the pl-259 myself. So to seal the connections, your recommendations?...

First is the cable type, we have 240F and 400F. The number refers to the diameter of the cable 0.240" and 0.400". The 240F is the smaller diameter of the two options. It is smaller and more flexible, the tradeoff is it has more signal loss than the 400F, so it's generally recommended for under 50' lengths.We offer the 240F in a single lead and dual lead configuration as an extension cable:Single Lead SMA Male to SMA Female:https://www.jefatech.com/collections/3g-4g-lte-antennas/products/tgx-04-a-001Dual Lead SMA Male to SMA Female:https://www.jefatech.com/products/dual-sma-antenna-extension-cable-for-4g-lte-5g-modems-and-routers/The larger diameter 400F has a lower signal loss than 240F but the tradeoff is it is...

A copper clad aluminum center conductor is the standard in the industry for RG-8 size low loss cable such as JEFA Tech Low Loss 400.  CCA is preferred due to the lower cost and lower weight vs solid copper.  All major manufacturers use copper clad aluminum center cores for this type of cable.  This includes Times Microwave LMR-400 and Commscope WBC-400 among other major brands. RF energy travels on the outside skin of the conductor, not the center, so it will be on the copper part of the center conductor and not the aluminum.  This is known as "skin effect".  There...