Rapid storage and deployment of 50ft RG58 coax

Perhaps a blue flashing one :wink:
73,
Rod

Thanks Andy for reminding me about RG174 feeders and that [elsewhere on this reflector] we were both defending the use of 10m of RG174 for QRP/low power on HF [attenuation on 30m and 20m is negligible].

I’ve just measured the length of the RG58 coax feeder supplied with my Cha MPAS Lite and it’s 15.2m (50ft) long (not 25ft as I guessed above), the same as for the MPAS 2.0. This is ridiculously too long for any normal SOTA activation.


The coax on a winder weighs 710g and is pretty bulky in my default rucksack. Contrast this with the 10m of RG174 I use with my linked dipoles and EFHWs. It weighs 222g and has a smaller flatter volume.

The latter doesn’t have an in-line RF choke but [unless there’s something special about verticals] that’s never been a problem for me operating 10w (max) portable.

I’ll be trying the RG174 coax with my MPAS Lite on my next activation. If it’s as good as the 15m of RG58, the latter will get consigned to sit-in-car portable and holiday-home ops.

3 Likes

My solution is to use RG174 on a Sotabeams winder. Do you need 15m? Will the extra loss make a difference?

I’ve been using RG-58 and RG-213 for years (25 years as a ham this year :open_mouth:), it wasn’t until I got the SOTAbeams Bandhopper that I was converted to RG-174.

Back before I saw the light, I used to do RAYNET and we often used RG-213 cable runs. I usually tape or cable tie a loop in the coax, then I just roll the cable around in my hands, keeping the loop the same diameter, before finishing with more tape or another cable tie.

I use RG-213 for my 5 element 2m beam when I do SOTA as the PL-259 or ‘M’ type is the Japanese version to match the socket on the beam. When cold, the cable is a bit stiffer, but it’s still not too bad to coil up. It’s amazing how flexible the cable gets on a hot day!

I use wire winders with my RG-174.

73, Colin

1 Like

Why do you need 50ft (= 16m!) of RG58 coax on a SOTA activation in the first place?

Instead of tinkering with cable winders I would dump the coax and use either a shorter length (3 - 6 ft should do) or use thin twin lead, which is easier to wind and less heavy!

Maybe I am just lazy, I don’t carry a lucky anvil either.

73 Heinz

2 Likes

I do the same with RG-58 and RG-174, both around 8 m long. Rolling the RG-174 I’m forming a loop with 4 or 5 windings first. With some practice it takes not so much time and it’s the version with the lowest weight and size. For deploying also rolling the loop in the hand.

73, Ludwig

1 Like

Classic Forum behaviour! Rapidly off topic, then…

here’s my solution to a different problem.
Why do you need 50’ of coax for a SOTA activation?
Don’t use that, use this.
Sarcasim that’s so heavily disguised, some if not all will see it as abuse. (MT privilege :wink:.)

Love it! :heart:

Mark, why are you Chasing /p. Just walk another 500m and you’ll have a S2S. Surely that’s the solution?

Cheers, Fraser

1 Like

Unfortunately my work lunch ‘hour’ doesn’t quite stretch to completing an activation, and believe me I’ve thought about it. I find being outdoors doing radio even for an hour is very therapeutic both getting the body moving and working the brain a bit too - and I’m always keen to give-back by providing activators with a contact. Sometimes it is very much appreciated if you are the magic #4. I don’t anticipate taking such a long run of cable on an activation, or indeed the MPAS2.0 most probably as it is on the heavy side, but for messing around with portable antenna configurations it can be useful to have a longer cable run.

It was one of those topics that I thought I’d ask on the reflector and there would either be a eureka moment with someone finding the perfect cheap article to repurpose as a winder, or as we have found such a thing doesn’t appear to have been identified (yet!)

I know I can’t live without cables but that doesn’t mean I find them much fun to work with. I appreciate how much time I save using the SOTABeams Band Hopper IV with winders over a bag of wires however. Convenience is everything!

Cheers for all the replies. Mark.

4 Likes

I ended up buying a pack of 5 cable winders from Amazon for £12.99 delivered: https://www.amazon.co.uk/gp/product/B01N0NU89Z

Just about the right size for this cable length, with some capacity to spare

Turn radius on the ends isn’t too tight.

Regards, Mark.

2 Likes

The trouble is recognising which end to pull which way. Sometimes I get it wrong and find I have generated the maximum possible number of knots!

The RF choke end of the coax goes to the vertical. I always start at the antenna and pay out the coax cable walking back to the rig position. I re-coil it walking in the other direction. That way that RF choke is always on the outside of the coil. But I still have problems with the RG58 wanting to knot even if I use the alternating-loop technique.

Although new to radio I’m not new to rope and cable management. What I’ve used for my rg58 coax is a army surplus “dump bag” or “dump pouch”. Keep an end out (this will be the bottom of the pile) then start feeding the cable in. It’ll twist and wind, just keep shoving, until you get to the other end. Pull the drawstring tight before it self ejects! Now you have both ends out of the bag. Don’t pull the “bottom” end out first, you’ll get a bag of knots. However you can connect to the bottom and just draw out what you need off the top. I’m faffing with some 20m of light coax so I can put up my antenna at the top and then go hide in some shelter.

3 Likes

Mark,
I have the MPAS 2.0 Lite version and ditched the coax. It’s too bulky and heavy.
For HF, I carry lengths of 5mtr & 10 mtr RG174 wound in figure of 8 onto a Sotabeams Midi winder.
This may not be most efficient for higher frequencies of the MPAs system.

I also use a choke from N9SAB, which seems to do just a good a job as the choke in the bulky coax supplied with the system.

The attached image has 10mtr on the right, 5 mtr on the left side of the winder and the choke


for size comparison.

73, Robert

3 Likes

Ha ha ha ha ha ha… made my night.

The wonderful Peter Kaye and Sian Gibson (who’s married to a chap from a village near my QTH).

1 Like

Robert, that’s good to know (for my intended use with my MPAS Lite). I’ve previously calculated the loss for 10m of RG174 that I use with my wire antennas (using an online calculator) and the loss is acceptable [to me] certainly for 3.5-14MHz.
image

The RF choke looks interesting. Before I buy one though, have you noticed any difference between using and not using it? Also, the eBay link you gave doesn’t give a power rating but just states ‘QRP’. I usually run 10W [from a KX2], which I assume is probably okay.

Andy

1 Like

I wouldn’t buy one at £53 by the time you’ve got it to the UK and paid VAT! Probably £10 of parts if you roll your own.

1 Like

This is my choke.

I’ll make you one for £50…

2 Likes

I understand the potential need when QRO from the shack. But before I pay even £5 for one, I’ll like someone to convince me that a CMC choke is even necessary for 10W to a portable antenna with a decent VSWR. Hence my asking if there’s a noticeable difference with or without the choke [rather than merely following the perceived wisdom for having one].

1 Like

Yes, it can be. I only made that because I noticed an issue on 20m with my EFHW. It might be because my homebrew rig isn’t in a proper metal case. So I suggest you only use one if you find you need it.

So, Richard, have you tried without the choke? If so, what happened [that was different]?

P.S. I’ve never needed one running 10W to my linked dipoles & EFHWs nor when I swapped out the MPAS coax (with choke) for coax with no choke to that vertical.

I’m trying to find out if the problem is real or not when QRP portable.