My 10m RG-174 feeder with BNC and PL259 terminations on a SOTAbeams winder weighs 191g and is very low profile in the rucksack, so more room for sugary snacks.
Okay, so my KX2 puts only 7W up the spout on 10m c.f. to 8W(?) with your fancy-pants Messi&Paoloni Airborne 5 coax. Is the extra watt or so worth going without the snacks?
Of course it matters because we are professionals not amateurs.
Well I am and you were 
Actually I probably wouldn’t bother replacing an existing cable run that is working. But the comment was to do with replacing RG-58 with RG-174 on a longish run. That gives more loss for less weight If you are about to buy new then you consider it because you save weight and get less loss over what you had. So it seems to be a win-win, price excepted.
Is the cost benefit worth it? Depends on what you measure but it’s a more higher tech piece of cable and that extra shininess appeals. Well it does to me especially if it’s not that much more.
Having trod the cheap connector/cable path and been tripped up so many times I now use quality cable and connectors. It’s come up before - all my RG-58 connectors I now crimp and use RS Components silver plated connectors. Is the Airbourne 5 Coax compatible dimension wise with RG-58 connectors? That will be the clincher for me if I can’t buy a pre-made cable.
Cheers, Mark.
Airborne 5 is the same size as RG-58 but the connectors are special to it. I only mentioned it as I bought an off-cut at FN rally for a few €’s and the M&P vendor had the matching connectors. It was noticeably light. My crimp tool for RG-58 worked perfectly with the genuine M&P connectors (BNC male and SMA male). If you have an RG-58 crimp tool then you are sorted.
Martin Lynch will make up cables using this coax but they appear to charge £18 for the privilege which is probably a fair commercial rate but made my wallet cry.
Do your own checking etc. Mark. I suggest this as if you want to replace a length of cable it’s well worth seeing if these modern cables that are lighter and lower loss are worth the cost. It’s not a simple decision as sometimes the benefit may only be 1.5dB or so but that could be enough to complete that super DX S2S qso!
I’m not sure this is true. Different RG58 BNC (for example) connectors may need different size crimp dies so there is no guarantee that all RG58 crimp tools will work. I found this out the hard way by making up a lead that was rubbish because the crimp was the wrong size.
I think the main losses in coax at “normal”* frequencies are resistive, and radiation through open weave braid.
Improving either of these has, in the past, involved more copper eg larger conductors, and thicker or multi layer braid. (Or foil, which is not ideal for flexibility)
I don’t doubt modern specs from M&P, but I’m intrigued to know how they achieve them in a lighter cable…?
*Dielectric loss used to be an issue at SHF, though they probably have improved greatly since I were a lad!
It’s a foam not solid dielectric. Also it’s only 84% braid of aluminium/magnesium wire over an aluminium foil screen for 100% screening. The centre is 1.1mm copper and they claim 17Ohm/km resistance.
I used a 0.213in die for the crimp which is the standard size for RG-58 I believe.
YMMV
That is the size I use so perhaps it’s OK with RG58. The problem for me was RG174 and maybe that isn’t standardised. I now use BNCs that use the same die for both cable types.
I’ve only been crimping for about 2 years and there’s lot to learn. Just sizing up a BNC for RG-174 it looks like 0.137in is die size to use. And since looking I’ve only just discovered that RG-59 is thicker than RG-58. I always assumed the inner was thinner to get the different impedance and never considered it was nearly 1mm thicker.
Unlike solder/compression fit where you can futz about practicing, you only get one chance with crimp connectors. I should really buy a bag of cheap tatty connectors to practice with. I only just discovered my ratchet crimp tool is self-releasing when you squeeze it closed enough 
Messi & Paoloni coax and connectors are undoubtably lovely and a pleasure to work with. I question how resilient a foil screen and foam dielectric will be when put through the regular coiling, uncoiling and general abuse that SOTA places on coax. It may be that the benefits are short lived.
I forgot to reply to this… You are right in that it wont be as resilient as ordinary coax. It depends on how tightly you coil it and the TX frequency in use. I replace coax used on SOTA every 3-5 yrs simply because it takes a beating and I’d expect this to be fine for HF for 3 years. You may see issues at 23/70cms when the cable has been used a lot but it should still fine at 10m. You wouldn’t be using this at 70 or 23 though even when new!
It’s normally now when someone comes along and says his end-fed doesn’t need any coax. To which the reply is my diesel car doesn’t need any petrol.
When a crimp is done right, the wire being crimped should break before is slides out of the crimp joint. This of course means all the pieces involved are the correct size and the joint has been crimped appropriately.
I thought this was true, but one of my co-workers showed me that was not the case. You can take a pair of vice grip pliers and squeeze on the points of the crimp ferrule after it has been crimped to quickly return it to a more round shape. The crimp ferrule can be quickly and relatively easily removed this way. You could consider reusing a crimp ferrule that has been removed this way, but for anything important you probably want to use a new crimp ferrule.
Doug, N7NGO
Hello Mark, If someone needs to apologize about his CW skills should certainly be me! Regardless, glad to hear you during my activation today, 73!