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11 meter coax for high power?

nitroturbo4u

Member
Feb 17, 2013
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SOUTH EAST COAST S.C.
Just aquired a Amp Supply Co LK550 HF amplifier.Has 3 of the 500z.Gonna let it loaf at 1500 watts only.
What i'm curious about is that my coax run is like 150 feet to the top of the beam.LMR 500?????This will be my longest coax run ever.
Thanks for any help.<can not stand it>
 

About the only 'bad' thing longer runs of coax have are a little bit more loss because of the length of the run, which is normal. If it's 50 ohm stuff, and the antenna's input impedance is 50 ohms then it ought'a work just fine.
I'd suggest that if you don't have a manual for that amplifier that you find one! Pay attention to the grid current readings, don't exceed them (unless you just like to buy tubes).
- 'Doc
 
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"hardline would be great..."

Also totally unnecessary and a waste of money. But if it makes you feel more 'secure' then have at it...
- 'Doc
 
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nitroturbo4u well it depends on what you call a lot of power,first of all your on
the right track, the reason why i say that is most ppl when they look for coax
and i will say the average guy don't know about coax, first let look your run,
150 ft that's a nice run, you what a coax that has a high velocity factor, meaning how fast the signal gets from point a=radio to point b=antenna,
and it runs numbers the higher the number the better the VL = Velocity factor.
now from my research i notice that every coax under lmr has a very low VL factor like .66, LMR coax starts up in the 80's like .85, the next thing i notice is
most companys rate their power rateings in peak power and the ppl looking at coax go wow at the high numbers not knowing its rated in peak watts you wanna look for RMS which LMR400 is about 2.4 k don't quote me because my
mouse is buggin out and i can multi task my web browser to pulls the date sheet
on the watts but i know am close, i wont get deep into it man but lets just say
after LMR400 the coax gets thick like hardline LMR600 hold about 5K rms and its real thick, the db loss factor is which is rated over a certain distance in feet. once again, coax below LMR has a higher db loss rate over a certain
distance. then you have to look at connectors the better the grade of coax the most the connector cost, am going laymen terms i got a pc problem. now connectors is a nother thing to look at, if your running big watts you want a connector thats going to hold up under pressure, dont let the guy tell you anything difference if they do they never ran anything over 3k, trust, me on that. 5k and higher you need connectors with teflon outter ring around the center pin,, why because watts is heat, and the cheap coax connectors break down under extreme heat.. next thing the average radio op is not going to spend $45.00 on a connector then they have to use 2 wrench's to tighen up the clamp nut, and before you do that you have to splice the coax, clean up the center core burrs man, the little stations dont want to go their all that..then solder the center pin, put a o ring before the clamp nut before tighting up the connector. this is my opinion what u should use, if your not gonna up grade, then use LMR400, the watts it can hold is 2.4k if your gonna upgrade your power then you need to move to heliax 1/2 its not that thick as LMR600 it holds more watts then LMR600 and the connectors for heliax is not that bad, i found some on flee bay for $7.99 and i bought all he had.. their andrews connectors, listen man, google everything i said because you got guys in forums that sit around trying the down play a person thoughts or opinions but i know what am talking about and am doing it in laymen terms, not antenna engineering talk.. so i would use LMR400 if your not going to upgrade your power and if you are go with 1/2 heliax. oh and FYI just in case one of these guys say man that coax is thick its not, as far as making a loop for the rotor, i got the cure for that also, homedepot sell aluminum flat pieces in 1/4 and 1/2 and i think its about 4 ft long you can make what i call a swing arm, its a piece of aluminum arm that u can make that bolts to the rotor clamps depending on how long you make it, that holds the cable loop outwards from the rotor, so it wont get caught on the rotor, matter of fact if the antenna your running has a gamma match, u dont need a connector on that end anyway, the big boys use wire lug connectors to attach the coax to the gamma match, the center goes on the base of the gamma match, the shield goes on the boom or the driven element in a pig tail form, its a better connection and u only need one connector now the one to the amp. so on the swing arm at the end of it use a rubber grommet the size of the coax and push the coax though it and run it up to the antenna wire tie it 2 the mast and connect it up and your done, oh and use that rubber tape stuff that like tar, if keeps the water out, i think its call antenna seal. that is my mouse is buggin out and i have to reboot my pc.
 
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Reactions: 2 people
nitroturbo4u well it depends on what you call a lot of power,first of all your on
the right track, the reason why i say that is most ppl when they look for coax
and i will say the average guy don't know about coax, first let look your run,
150 ft that's a nice run, you what a coax that has a high velocity factor, meaning how fast the signal gets from point a=radio to point b=antenna,
and it runs numbers the higher the number the better the VL = Velocity factor.
now from my research i notice that every coax under lmr has a very low VL factor like .66, LMR coax starts up in the 80's like .85, the next thing i notice is
most companys rate their power rateings in peak power and the ppl looking at coax go wow at the high numbers not knowing its rated in peak watts you wanna look for RMS which LMR400 is about 2.4 k don't quote me because my
mouse is buggin out and i can multi task my web browser to pulls the date sheet
on the watts but i know am close, i wont get deep into it man but lets just say
after LMR400 the coax gets thick like hardline LMR600 hold about 5K rms and its real thick, the db loss factor is which is rated over a certain distance in feet. once again, coax below LMR has a higher db loss rate over a certain
distance. then you have to look at connectors the better the grade of coax the most the connector cost, am going laymen terms i got a pc problem. now connectors is a nother thing to look at, if your running big watts you want a connector thats going to hold up under pressure, dont let the guy tell you anything difference if they do they never ran anything over 3k, trust, me on that. 5k and higher you need connectors with teflon outter ring around the center pin,, why because watts is heat, and the cheap coax connectors break down under extreme heat.. next thing the average radio op is not going to spend $45.00 on a connector then they have to use 2 wrench's to tighen up the clamp nut, and before you do that you have to splice the coax, clean up the center core burrs man, the little stations dont want to go their all that..then solder the center pin, put a o ring before the clamp nut before tighting up the connector. this is my opinion what u should use, if your not gonna up grade, then use LMR400, the watts it can hold is 2.4k if your gonna upgrade your power then you need to move to heliax 1/2 its not that thick as LMR600 it holds more watts then LMR600 and the connectors for heliax is not that bad, i found some on flee bay for $7.99 and i bought all he had.. their andrews connectors, listen man, google everything i said because you got guys in forums that sit around trying the down play a person thoughts or opinions but i know what am talking about and am doing it in laymen terms, not antenna engineering talk.. so i would use LMR400 if your not going to upgrade your power and if you are go with 1/2 heliax. oh and FYI just in case one of these guys say man that coax is thick its not, as far as making a loop for the rotor, i got the cure for that also, homedepot sell aluminum flat pieces in 1/4 and 1/2 and i think its about 4 ft long you can make what i call a swing arm, its a piece of aluminum arm that u can make that bolts to the rotor clamps depending on how long you make it, that holds the cable loop outwards from the rotor, so it wont get caught on the rotor, matter of fact if the antenna your running has a gamma match, u dont need a connector on that end anyway, the big boys use wire lug connectors to attach the coax to the gamma match, the center goes on the base of the gamma match, the shield goes on the boom or the driven element in a pig tail form, its a better connection and u only need one connector now the one to the amp. so on the swing arm at the end of it use a rubber grommet the size of the coax and push the coax though it and run it up to the antenna wire tie it 2 the mast and connect it up and your done, oh and use that rubber tape stuff that like tar, if keeps the water out, i think its call antenna seal. that is my mouse is buggin out and i have to reboot my pc.

ok am back pc rebooted, sorry for the post not lining up i had mouse problems
 
C.K. Says "Schools in session!!" LMA:laugh:!!! C.K. always seems to just pop outta the woodwork!!!


I couldn't resist it. I was at work, on the night shift, reading that on a tiny little Motorola smartphone screen and it just popped into my head about the same time the eyeballs started to water from squinting. :blink:
 

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