coax choke question

[Beetle]

Times Microwave is also in the business of selling coaxial cable - often to those who try to bend LMR400 into a 1" radius.

The US Navy mandates at least 13x the cable diameter to determine bend radius. That explains why the Navy rarely has a problem with kinked coax. For amateur installations, 10x is close enough and easier to figure in your head. The usual biggest problem is forgetting that you have to double the radius to get the diameter of the coil form/mandrel to use.

 

[GnG8d]

Times Microwave has always seemed like a reputable company selling a reliable product. Amateur radio surely makes up a very small percentage of their business and I'm sure their corporate clientele wouldn't appreciate being lied to. I suspect Beetle, that you may be referring to an old, outdated mil-spec. Or, Times Microwave does specify a 4" minimum radius in a situation where the coax will be repeatedly bent. Maybe that's what you are thinking of.

Many times on this and other forums, people are referred to the manufacturers data sheet for answers. How is this any different?

 

[GnG8d]

I wouldn't want to try that where the sun is beating down on it. I have to wonder if that is a simple bend lime a right angle or if in fact it is for a full circle repeated several times like a choke. Isn't LMR400 solid centre?

I don't really see where they make those distinctions. With all that said, I wouldn't be afraid to make a 2" radius wrap, but I'd be leary maybe on a 1" radius wrap.

 

[Road Squawker]

(edit)... Or, Times Microwave does specify a 4" minimum radius in a situation where the coax will be repeatedly bent... on this and other forums, people are referred to the manufacturers data sheet for answers. How is this any different?

I just checked their site, I couldn't find anything about repeatedly flexing it http://www.timesmicrowave.com/ and they state LMR 400 can be bent to a 1 inch radius, and as per note 5 :with "less than 1 ohm impedance change at the bend"

1 inch??? I dunno 'bout that

 

[GnG8d]

I just checked their site, I couldn't find anything about repeatedly flexing it

LINK

 

[W5LZ]

What happens when you repeatedly flex any solid conductor? I don't think I'd do that, you know? As for why you'd 'flex' it at all, I don't know. Keeping any cable from flexing isn't a bad idea, but not always practical. Oh well, it won't last forever anyway...
- 'Doc

 

[Road Squawker]

LINK

link,...... err.,..............Welcome to Times Microwave

 

[GnG8d]

link,...... err.,..............Welcome to Times Microwave

I don't understand what you're missing, page 2 of the pdf I linked shows the mechanical specifications.

Bend Radius: installation
in. 1.00
(mm) (25.4)
Bend Radius: repeated
in. 4.0
(mm) (101.6)

 

[hotrod]

i saw on this fourm somewhere a 8x8 choke as close to feed point as possible

 

[Road Squawker]

I don't understand what you're missing...

I posted a link to the manuf web site,

AFTER that, you post a different link to the same manuf.

the info is DIFFERENT , the times microwave site has conflicting info depending on which link you follow


whats so hard to understand about that?.:tongue:

 

[GnG8d]

I posted a link to the manuf web site,

AFTER that, you post a different link to the same manuf.

the info is DIFFERENT , the times microwave site has conflicting info depending on which link you follow


whats so hard to understand about that?.:tongue:

Beetle made reference to .405" cable and if I click your link, then products<cable<lmr<lmr400 I come up with the exact PDF that I linked directly.

So you're either still confused or not making your point very clear.