Magnum S9 and LMR400

[W5LZ]

Got good news and bad news for you. TM LMR-400 certainly isn't going to be bad at HF, but it's also not all that great either. The differences in loss between it and a comparable sized coax isn't significant at all. And if you think the center conductor of TM LMR-400 is solid copper, I have some bad news for you. It's copper plated aluminum. Oh well...
- 'Doc

 

[Robb]

Got good news and bad news for you. TM LMR-400 certainly isn't going to be bad at HF, but it's also not all that great either. The differences in loss between it and a comparable sized coax isn't significant at all. And if you think the center conductor of TM LMR-400 is solid copper, I have some bad news for you. It's copper plated aluminum. Oh well...
- 'Doc

The losses at lower HF freq's are negligible; yes. But as you know at 24mhz and above, the amount of loss begins to rise considerably. It is a factor to deal with at 27mhz at ~65 ft or more in length.

The guy that started this thread is using only 18 ft. Think I would use LMR-240Flex. It can deal with up to 1kw and is a narrow diameter and better for dealing with a mobile installation - IMO.

Even if the center conductor is copper plated; the current flows on the outside of the conductor anyway. The quality of that copper is also somewhat significant. Something you once told me when I was still a newbie here.

Having a quality insulator material between the shield and the center conductor is significant too. If it allows for too much movement/deviation, it can be the cause of a poor SWR for one.

Just goes to prove that the news can be skewed to get people to think differently about something . . . Thanks again, Doc . . .

 

[Mudfoot]

So you're not really a mean old daddy! :laugh: It's hard to pass up "free"!

73,
RT307

Just remember to pay it forward...