whats the longest coax you have seen in use?

[209 first class]

i have a hill kinda near the house with a fairly tall tree, it would put my antenna about 60 feet higher than where it is now mounted on the house. problem is i would need probably 250- maybe 300 feet of coax. i would use regular rg8x, hardline or lmr is pretty much outta the question due to price. (besides, i would have to hire the local treeguy to top the tree and put it up,i will guess $750 for that ) im not great at math or figuring out the line loss ect. whats your opinion on if the length of the coax will rule out and height advantage ??? for instance it may do no good being higher if only a small amount of power is making it to the antenna, and even worse, the receive trying to make it back to the radio... whats the longest normal coax you have seen someone using on cb frequencies? 209

[Slim Jim]

Here's a loss calculator page I found on google...it might be of some help to you.

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copy and paste that link above...if it doesn't work, just search "coax loss calculator" on google and click one of the top links. I don't have any "real life" experience with a coax run over 100'. Hope the link helps, though!

[tonyhatchetman]

well I'm using 100 ft on my base but trimmed it back some to give me 3 ft rule so its probably about 99 ft

[montecarlossfan]

eh if ya lose a lil..just up the power lol

[KW KID]

You would benefit greatly by being on top of the hill. Try and find a 500 ft. spool of LMR-400 or LMR-600. Loss @27Mhz @ 300ft. is still quite low. Probably cost you around $250 bucks, and you'll have left overs. As for getting in the tree, why not rent a basket loader, or even contact a sign repair company that has a boom truck. It would be only a 1 hour job. Just do a really good job on the coax connector and seal it really good, and take the load off the coax connector (the weight of the cable pulling down), because you don't want it to come loose!

If you get it up, post pictures!

[BtyMONSTER]

for way less than $750 you could put up a nice beam and rotor on a guyed mast .

[bullet]

This is not a CB antenna,but it may give an idea about the lost and gain.
I had a TV antenna at my house in the country. This is a few years ago. Before little Sat. set. I had it 30 feet high with 70 feet of coax. I wanted to catch better so I had a light pole in the yard, but it was about 120 feet form the house. I got the antenna about 90 to 100 ft high and added about 350 foot of coax. I could catch stations 3 times as for.
I know it is not the same. You have to receive and transmit. Myself I think good coax and the high the better. I would think to a certain point. I don't know that point. Getting it higher will help. If you have to pay that much to get the antenna up that tree you may be better off putting a tower on the hill and get even higher and more stable.
Good luck.

[80 meter man]

I heard a saying that coax has no loss if it's run straight up!!LOL LMR-400 would run 300 feet OK and as the other guy said if you buy it by the spool you can get it cheap. You can go with an LMR equivalent for real short money. The copy cat cable has almost identical specs.

Check this real out. It looks good to me and you cant beat the price!!

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[distortion69]

Height/elevation is a lot more important than a few watts. Trust me when I say this.

I am at the lower part of the elevation, and my antenna is at 80 ft, and I get walked all over by guys with antenna's at 60 ft and half the watts Even losing half your wattage out the coax would still be tremendously far better if your antenna is way higher. I'm only about 60-70 ft lower elevation than the folks I am shooting out against.. It took the best ground plane there is i10k, and 4kw to take out some of the high elevation locals with crappy antenna's and 1000 watts due to height One of them still gets me every time That's what the beam and a 100' tower is for to make up some of the difference

Power is a small part of the equation..

FWIW: 750 is way too much, there are 3 guys down here who top out tree's and install antenna's for $100-$150..

I paid $100 for my i10k to go up, and $100 for it to go down.. and he had to top it out when it went up and assemble in tree. Took about 25 minutes. Threw rope, ran up tree, lag bolted it in, got down.. tree is still healthy.

Peace,
Josh

[19dt2120]

There is an other solution, use an open line or Wireman.
It's much cheaper and you have less loss
>

Code: Select all

LMR400 
 Results
Freq:27Mhz
swr 1:1
Line Length:300Feet  
Power In: 100W 
Matched Loss:1.898dB  
SWR Loss: 0 dB  
Total Loss: 1.898dB  
Power Out: 64.599W  
 
600 ohm Open line

Freq:27Mhz
swr 1:1
Line Length:300Feet  
Power In: 100W 
Matched Loss:0.304dB  
SWR Loss: 0 dB  
Total Loss: 0.304dB  
Power Out: 93.244

Inside your house u use coax than outside > 1e a 1:4 balun > openline (diy or wireman 450 ohm) X x feet) > balun 1:4 > a few feet of coax >antenna

[209 first class]

montecarlosfan: good idea, but the receive is what im most worried about. last time i looked, lmr cable was over a buck a foot for the solid stuff. the loss calculator is cool, but i cant tell how much receive i will lose by the calculations, i dont know how to convert it to what my ears would notice. bullet: thanks that gives me some hope. 80 meter man: interesting ! i have never heard that. bootymonster: i presently have a beam, the pattern/pickup is really tight. 30 degrees on the rotor either direction and i lose the locals. so i put up a maco v5/8 vertical and its working much better than expected. i was imagining about getting it higher, but question the coax length. distortion69: encouraging words, thanks ! 209

[drdx]

I've only ran about 200 ft, and it worked fine, and that was a long time ago with some 213, and things have improved since then. Raising the altitude of that antenna will only help and any loss incurred with the use of high quality cable will be more than made up for by the improved location. The antenna is the most important part of your station. You've got a nice **Censored** of gear there, let it breathe with a nice antenna, the best one you can do in that location. Is there a way to maybe put together a portable setup and throw up a "mock up" antenna in that location, even if it is just a dipole strung up there by throwing a rope over a branch? It might give you a decent ideal of the possibilities of the upgrade. Shop around for the cable. That quantity can be had for less per foot. I'd call HRO or AES, or a cable specific place. Buy the 500 ft roll, use all you need, sell the rest on here to recoup your cash, or make a bunch of high quality jumpers and sell those. Shipping might be high, so try a local source if you can. If you were crafty enough, this could cost you practically nothing.


-drdx

[drdx]

I looked a little, and saw real LMR for 370 a 500 ft. spool, and some knockoff stuff for much cheaper, in the low 200 range. I wouldn't be afraid to use a non name brand if it made the difference in not doing it at all. -drdx

[WEASEL]

We sell LMR400DB for about .80 per foot where I work. I think you should be able to go to a local LMR shop and buy some. We always have some on hand here and we usually buy it by the 500' spool. We use the crap out of it for all sorts of stuff, the 400DB is even direct burial so you could bury it all the way from your house to the tree for a nice looking install.

[Billygoat]

I can't help you on the receive part, but i feel your pain... my elevation is 780 feet, and i have a mountain in the back yard that's 1200 feet, i have to make up the other 420 feet to get over it... i had a maco V5/8 60 feet in the air on a tower and could not get out.. people stepped all over me even with me running power. I have a pine tree in the far corner of my property that is about 100-120 feet high and around 100 feet from my house. I bought a I-max 2000 and 250 feet of RG8 Mini... that's right i said RG8 MINI!!! .. I use a Eagle 2000 ( Same as Galaxy Saturn ) I borrowed a Bird meter from a friend, and wrote down what my radio dead keyed at... i disconnected the Bird and hooked up the 250 Ft of RG8 Mini and installed the Bird at the other end and a jumper to the Antenna.. Surprisingly on the Bird i lost 1.5 watts... But after i got the antenna up in the tree... the tip of it is around 140 Feet.. I'm still below the mountain but i gain on a average of 3 - 6S units on most of my local contacts... Hope that helps.

[crazytruker]

montecarlosfan: good idea, but the receive is what im most worried about. last time i looked, lmr cable was over a buck a foot for the solid stuff. the loss calculator is cool, but i cant tell how much receive i will lose by the calculations, i dont know how to convert it to what my ears would notice. bullet: thanks that gives me some hope. 80 meter man: interesting ! i have never heard that. bootymonster: i presently have a beam, the pattern/pickup is really tight. 30 degrees on the rotor either direction and i lose the locals. so i put up a maco v5/8 vertical and its working much better than expected. i was imagining about getting it higher, but question the coax length. distortion69: encouraging words, thanks ! 209

I've seen you say before that you are a wealthy man so what's the snag on coax cost? skip a fueling on the ferrari and get some good coax. Better get back touring with Staind for some cash

[209 first class]

i dont recall saying that. which post? if i did, excuse me, my modesty must have slipped. there is a difference between wealthy and frugality.i enjoy being frugal. for example my uncle kenny is very wealthy, he was smart with investments back in the 1960's. but he still insists all us neices and nephews save our old car motor oil and bring it up once a year when we visit so he can use it in the winter for heating the garage where he works on boats ect in the winter,lol. i remember as a kid my dad putting the stinky boxes of oil in the back of the station wagon when we went up to maine to visit. being frugal is kind of like a sport. i guess i could get hardline the size of my arm, or even better, have power run out to the antenna tower, build a weatherproof enclosure or tiny shack, and have the amp out there where it would only need enough coax to go up to the antenna, and the only loss would be from the driver to the amp, instead of between the power amp and antenna. but its more fun this way, and i will have a few dollars left over for another radio or somthing. 209