The common types are, I freely admit I wasn't completely correct.
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
LMR-400 for Ham Radio/cb radio
- Thread starter 1iwilly
- Start date
50 MHz is VHF, We are talking about HF which CB falls in. Might as well compare losses at microwave frequencies because it'll make LMR look even better!
This is a CB thread.
"Those fractions of a dB on HF will never be noticed and basically like I said earlier, if numbers make you feel better, don't stop short of getting the absolute best you can like 7/8th Heliax".
"
"Those fractions of a dB on HF will never be noticed and basically like I said earlier, if numbers make you feel better, don't stop short of getting the absolute best you can like 7/8th Heliax"
0.7 dB. will reduce power to the antenna by 12.1W. Your "fractions" are converting real power into heat and not being radiated by the antenna. That amounts to almost 1.75W per 0.1 dB.. A low loss line that is capable of delivering = or > 90% of available transmitter power will have line loss of < or = 0.5 dB., considered low loss in Land Mobile Radio service.
"Those fractions of a dB on HF will never be noticed and basically like I said earlier, if numbers make you feel better, don't stop short of getting the absolute best you can like 7/8th Heliax"
0.7 dB. will reduce power to the antenna by 12.1W. Your "fractions" are converting real power into heat and not being radiated by the antenna. That amounts to almost 1.75W per 0.1 dB.. A low loss line that is capable of delivering = or > 90% of available transmitter power will have line loss of < or = 0.5 dB., considered low loss in Land Mobile Radio service.
Last edited:
Geez, according to your calculations:
0.7 for RG213 and .05 dB for LMR400, that IS fractions of a dB difference.
Here is the truth without using a frequency above HF you used to prove your point where LMR excels and it's well known that RG213 will drop off.
At 15 MHz which is the center of the HF band, here is the calculations for cable run efficiency which is the percentage of power delivered.
LMR400 @ 100ft is 89.6%
RG213 @ 100ft. is 84.5%
That's basically 5% difference or 5 watts of a 100 watt output. Big woop!
As the frequency increases especially on 2 meters and up, yes the efficiency of 213 decreases dramatically(so does LMR but not as much) but on 160 meters, the efficiency is nearly equal enough between both types so the difference is insignificant. I never heard of anyone using a significant length of RG213 on a base station 2m/440 antenna. The percentage difference on 70cm is 22%. Yet, on the new 630 meter band, the difference between the 2 types is only about half a watt!
Here are links of the calculations.
LMR400
https://www.timesmicrowave.com/Calculator?Product=LMR-400&Frequency=15&RunLength=100
RG213
https://www.timesmicrowave.com/Calculator?Product=RG-213&Frequency=15&RunLength=100
Again since you savor every precious watt, you should be using the largest and best Heliax cable you can afford because even LMR400 doesn't measure up as good as Heliax.
Yep, perfect vs good enough.
Anyone used Nemal 1180 coax?
https://nemal.com/products/low-loss-50-ohm-lmr-type-coaxial-cable
Any good? Great price.
https://nemal.com/products/low-loss-50-ohm-lmr-type-coaxial-cable
Any good? Great price.
difficult to determine since they don't provide any attenuation vs. frequency or electrical specifications, unlike times microwave systems.
https://www.timesmicrowave.com/DataSheets/CableProducts/LMR-400.pdf
here is my conversation with a representative onsite.
Hi there, we are available if you have any questions!
where are the attenuation vs. frequency and electrical specifications?
9:25 AM
Please send us an email at m.torres@nemal.com
no thanks, if you can't provide that information on your website i'll stick with the TMS LMR-400. have a good day.
Hi there, we are available if you have any questions!
where are the attenuation vs. frequency and electrical specifications?
9:25 AM
no thanks, if you can't provide that information on your website i'll stick with the TMS LMR-400. have a good day.
Uhhhhh.... yeah. If you consider your product on a par with LMR400 you are going to be lighting up the sky with the performance specs.
This does seem a little weird.
This does seem a little weird.
here is my conversation with a representative onsite.
Hi there, we are available if you have any questions!
where are the attenuation vs. frequency and electrical specifications?
9:25 AMPlease send us an email at m.torres@nemal.com
no thanks, if you can't provide that information on your website i'll stick with the TMS LMR-400. have a good day.
feedline loss also negatively impacts receiver sensitivity, moreso than tx power.
No difference electrically. The cable may be a bit stiffer but that is all. Really GOOD quality heliax such as Andrew LDF4-50 is copper clad aluminum. We beat this to death in another thread somewhere about pure copper versus copper clad aluminum. If copper clad aluminum is good for commercial users into the GHz range it's good enough for ANY ham or CBer.
boy howdy . got that shit rite. im using both ultra flex tmc 400 and tmc lmr 400 on both cb and 2 meter 70 cm radios. never a glitch n i send a tad o FIRE UP THE WIRE.
i got a relative that installs buisness band radios i buy coax from. he been in buisness 40 years n still busy so i kinda take his word for fact and buy what he gets great service out of.
and captain kilowatt knows too ,been in radio big time for years