Coax Menu

[Greg T]

Well, I'm going to install a new ground plane soon and decided to look up some coax. Yeah, I'm perfectly aware of Rg213, LMR400 and all the trendy stuff. BUT, It's all much too stiff and heavy for my taste and needs.
So, I go to Times Microwave and start studying spec sheets. Unless I'm totally missing something, most people are spending 10 times more money than they need to and gaining nothing. For instance, Your standard RG8 is stiff and heavy...hard to work with. So is RG213 and LMR400. The loss at 30mhz thru 100' varies between 1.7db and 2.3db, depending upon the cable. The cost is very expensive. BUT, I found LMR-195 which is the same diameter as RG58, only has a loss of about 1.9db, good for 1000 volts, and costs about 62 cents per foot. EXTREMELY flexible and is double shielded as well. Also, much much easier to construct an RF choke/balun with. Why is nobody using this stuff?

 

[M0GVZ]

You should look at Ultraflex. It comes in both 7mm and 10mm diameters, same as RG58 and RG213 but is extremely flexible and very low loss.

 

[sp5it]

LMR-195 which is the same diameter as RG58, only has a loss of about 1.9db, good for 1000 volts, and costs about 62 cents per foot.

Nice! Here it costs 3.40$/m

 

[Greg T]

Nice! Here it costs 3.40$/m

Tessco right here.

You should look at Ultraflex. It comes in both 7mm and 10mm diameters, same as RG58 and RG213 but is extremely flexible and very low loss.

But the ultra flex has a bit more loss and is nearly twice the price.

Tessco lmr ultra flex

 

[543_Dallas]

High power is why most overlook the smaller coax. The spec sheet says the lmr195 is rated for 2.5kW peak power, has 2db loss at 890 (avg) watts on 30 mhz. 3db loss would be losing half your power. That's not acceptable to me.

Lmr400 is rated for 16kW peak power, has .7db loss at 3330 watts on 30 mhz. It's worth it to me to pay that premium. I have found that you can feel coax warm up at less than it's rated power. I like overkill and went with with off brand lmr600. It's never had more than 5kW through it and probably never will.

The center conductor for the 195 is .037" or slightly smaller than 18 awg. 890 watts into 50 ohms is around 4.2 amps. It's adequate but I wouldn't use the stuff for anything but a short jumper. For a receiving only antenna rg6 works well and is 11 cents per foot at the hardware store.

 

[Greg T]

I used the loss calculator on their website. At 27mhz it shows 1.9db. That is on par with the 400 and the 213. RG8 is a bit less. 8x is a bit more. I'm running 30 watts AM and 500 pep ssb. My loss will be negligible, as would about 80% of the cb population

 

[BJ radionut]

https://kv5r.com/ham-radio/coax-loss-calculator/

 

[Captain Kilowatt]

I might be in my late 50's but I am still man enough to wrangle that "stiff" coax cable. LOL Hard to deal with? Again.....LOL Been using RG8 for over 40 years and don't see your point. I managed to get a bunch of Andrew LDF4-50 half inch HELIAX and that is my main feedlines for all my antennas. If you think RG8 type cable is hard to manage you should try some heliax sometime.

 

[Greg T]

I might be in my late 50's but I am still man enough to wrangle that "stiff" coax cable. LOL Hard to deal with? Again.....LOL Been using RG8 for over 40 years and don't see your point. I managed to get a bunch of Andrew LDF4-50 half inch HELIAX and that is my main feedlines for all my antennas. If you think RG8 type cable is hard to manage you should try some heliax sometime.

Nope, I'm a 67 year old athsmatic with two back surgeries under me and no feeling in my feet or finger tips. I'm all done with 1/2" feed line. Been doing that for 50+ years. Can do it no longer. I just went looking for the lowest loss per cost ratio. When I see 1.7 db RG8 compared to 1.9db LMR-195 theres no question. Especially since I only need 60 feet inclufing the choke. And, I can get 100 feet for 65 bux.

 

[freecell]

"For instance, Your standard RG8 is stiff and heavy...hard to work with. So is RG213 and LMR400. The loss at 30mhz thru 100' varies between 1.7db and 2.3db, depending upon the cable."

the matched line loss attenuation of LMR195 @ 30 mhz. is 2.0 dB. per 100 feet. https://www.timesmicrowave.com/DataSheets/CableProducts/LMR-195.pdf

the matched line loss attenuation of LMR400 @ 30 mhz. is .70 dB. per 100 feet. https://www.timesmicrowave.com/DataSheets/CableProducts/LMR-400.pdf

LMR195 has almost 3 times the loss of LMR400 @ 30 mhz..

 

[groundwire]

Just buy some generic rg58u from ebay and be done with it

 

[Greg T]

"For instance, Your standard RG8 is stiff and heavy...hard to work with. So is RG213 and LMR400. The loss at 30mhz thru 100' varies between 1.7db and 2.3db, depending upon the cable."

the matched line loss attenuation of LMR195 @ 30 mhz. is 2.0 dB. per 100 feet. https://www.timesmicrowave.com/DataSheets/CableProducts/LMR-195.pdf

the matched line loss attenuation of LMR400 @ 30 mhz. is .70 dB. per 100 feet. https://www.timesmicrowave.com/DataSheets/CableProducts/LMR-400.pdf

LMR195 has almost 3 times the loss of LMR400 @ 30 mhz..

I ended up with LMR-240. Works perfectly and VERY low loss.

 

[Groundhog KSS-2012]

I ended up with LMR-240. Works perfectly and VERY low loss.

Excellent choice. It's what I always use in my mobile installations and what I always change my mag mounts to.

 

[Greg T]

Excellent choice. It's what I always use in my mobile installations and what I always change my mag mounts to.

I went to Times Microwave website and used their calculator to determine what I should use. I was considering LMR-400. I think there was maybe .4 or .5% difference in loss between the two. That doesn't cover the cost difference.