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Old 09-21-2019, 03:07 AM
country_boy country_boy is online now
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Originally Posted by JDH View Post
Rated for:
976 watts at 1 MHZ
down to 108 watts at 1000 MHZ

At 70cm it is good for 120 watts with a loss of 19.1 db dB/100 feet.

Data sheet:

It is ideal? No. Will 10 feet of it in a mobile station cause a noticeable loss of performance? No.

Try running 5 miles in combat boots wearing a gas mask. BTDT.
As you note, the loss (in dB) is independent of power. You are going to loose 1/3 of the power in 10’ at 440 MHz, regardless if it’s a 50 watt mobile or a 5 watt HT. I wouldnt consider 2 dB to be unnoticeable, but it can usually be tolerated.

At high power, a Lossy coax can become hot, and may damage the cable, particularly if the cable is pinched, or heated by solar radiation.

I’ve run LDF-4 close to its rated power (400 watts) at C band, and it was too hot to touch. It made a good dummy load. At VHF the cable has on .8 dB/100’.

ETA, RG174 is actually typically better shielded than RG-58. We use a lot of it to connect to satellite modems at L band.
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