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Author Topic: Any tips on preparing LMR-195 Ultraflex?  (Read 196 times)

KF0JPV

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Any tips on preparing LMR-195 Ultraflex?
« on: February 03, 2023, 07:24:54 AM »

Most of the Ultraflex posts I've found are about LMR-400, which is a massive size difference.  So it is probably a bit more forgiving than the LMR-195 Ultraflex (it's all comparative, right?).

For portable, patch cable, and temporary setups, I found myself using Times Microwave LMR-195 because most of amateur radio time is spent in a high noise environment.  So that extra shielding makes a difference.  But straight LMR-195 was a bit stiff.  So I bought ~100ft of Times Microwave LMR-195 Ultraflex to use in places that are more temporary.  More than double of what I actually needed, but I knew it would take time to learn how to work with it.

So far it has been nothing but a pain.  Found out the hard way most coax prep tools don't work on it, and forum comments support it.  That lead me to the box cutter blade.

With a razor blade, I'm finding it hard to:
1. Cut to the stranded core, but not damage a strand.  After a couple of attempts, I can do this consistently or only damage one strand.  The spring loaded cutters were useless because they use too much pressure and damage strands.

2. Pull the foam off without damaging multiple strands (pull them off!), and there aren't many in this coax.  This is pretty hard for me.  I've tried the following:
  a. Pulling straight off; guaranteed way to loose many strands.
  b. Use the razor to slice along the side of the foam to open it up.  Kind of works, but it's hard to get a straight line and can instead make a mess.
  c. Use various snips (aviation snips, flush cutters, diagonal cutters, sewing scissors) to cut along the side of the foam to then peel off.
      Edit: These work the best, but are still hard to cut consistently or at all.  The foam rolls around easily.  The clamps/securing methods I've used just get in the way of cutting along the side.

3. Cutting through the shield when just trying to cut the jacket.  I can't seem to find the right pressure that consistently cuts the jacket without going through the shield at some point in the rotation.  I've tried:
  a. Various pressures rotating the blades around the jacket.
  b. Using the spring loaded cutters but fighting to keep it open
  c. Some larger sized wire strippers.  Unfortunately mine only go up to 8.  Maybe I just need to buy one for 6 and 7.
      Edit: This kind of works, sometimes.  Maybe I'm just using the wrong one.

#1 isn't insurmountable and takes practice.  #2 is the big problem, and I'm out of ideas.  #3 isn't impossible, but it is terrible to work through #2 just to ruin everything by cutting through the shield.
« Last Edit: February 03, 2023, 07:31:46 AM by KF0JPV »
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KB7TT

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #1 on: February 03, 2023, 07:40:43 AM »

Buy the tools for it, you won't regret it.
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K1VSK

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #2 on: February 03, 2023, 08:45:40 AM »

Have a local teach you how. It really is a lot easier than you describe.
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KF0JPV

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #3 on: February 03, 2023, 08:50:06 AM »

Buy the tools for it, you won't regret it.

I love the Times Microwave prep tools.  They were totally worth the money for all the coax I use.  The tools for 195/240 don't seem to work for Ultraflex.  The rubbery coating gets caught, twists, and tears or jams instead of being cleanly cut.
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W1VT

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #4 on: February 03, 2023, 09:12:54 AM »

I have a thermal wire stripper that I routinely use for removing Teflon insulation.  They make models for coax insulation removal.
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KF0JPV

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #5 on: February 03, 2023, 09:13:35 AM »

Have a local teach you how. It really is a lot easier than you describe.

Yeah, maybe I'll have to physically go to a meet instead of the virtual ones and see if someone can show me what they do.

I've used a razor on normal LMR-195 and 400 for connectors that use different core and shield trim lengths than the Times Microwave tools.  No mess ups with the cutting then; can even cut long, check how the connector fits, then trim again.  My problems are caused by the Ultraflex having such a softer shield, but then an extremely stiff core.
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KF0JPV

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #6 on: February 03, 2023, 09:25:41 AM »

I have a thermal wire stripper that I routinely use for removing Teflon insulation.  They make models for coax insulation removal.

Sometimes throwing a better tool at the problem solves it well enough to move on to the next problem :)
Any particular models you can recommend?

I see Hakko has an FT-802.  Their FT-801 and FT-800 were discontinued.
https://hakkousa.com/whats-new/stripping-with-thermal-wire-strippers.html

I'll have to rethink my tool priorities.  A rework tool was next on the "too expensive to buy on a whim" list.  I'm only OK at soldering, do it every month or two, but terrible at rework, which occurs every few projects.  But when I make cables, it is 4-10 of them, and it is a few times a year.  Plus I can use the thermal wire stripper for wire antenna building.
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W1VT

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #7 on: February 03, 2023, 10:26:12 AM »

I use an old Teledyne I bought a long time ago before Hakko soldering tools became popular.
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KF0JPV

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #8 on: February 06, 2023, 12:25:04 PM »

Thanks everyone!  I have a plan now:

1. Try using larger sized gauge wire strippers to help with the jacket cutting.  This might help with issue #3.
2. Go to a meet and try to find an elmer there that can show the process.  This could help find mistakes or simpler ways to handle #2.
3. Get a thermal wire stripper eventually just to cleanly strip off the Teflon for issue #2.
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W1VT

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Re: Any tips on preparing LMR-195 Ultraflex?
« Reply #9 on: February 06, 2023, 12:44:41 PM »

Teledyne makes a TW-6 thermal stripper designed for coax cables.
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