Heliax / Cellflex mounting.

[VK2NR]

Hi,
I have 4 parallel runs of Cellflex LCF78-50 (Heliax LDF5-50 equivalent) to secure to the side of a two-storey brick house.
I was initially looking at multi stacked cable hangers, however they are quite expensive for what they are - a few bits of moulded plastic and a short piece of stainless allthread.
I don't really want to go to the trouble and expense of installing a cable ladder / tray system, and I am also trying to minimise the visual impact.

Knowing that Amateur Radio types are inventive and frugal, what are others out there using to secure Heliax type cables?
Do any of you commercial installers possibly have a good source of hangers and brackets?

Looking forward to any ideas!

Cheers,
Dave.

[ZL4TAE]

Dave
Have a look at the PVC trunking for Air Con installations
Good luck Terry ZL4TAE

[VK2KRR]

Dave

Ive used 25mm pipe saddles directly onto the cable and screw into the surface u want to run them across.
Fairly simple but effective.

[VK2XSO]

Yep, we chuck out hangers for 78/LDF5 all the time. Shame you didn't want them 6 months ago, we had to pay to have a scrappy take them away.
How many do you want? I'm not sure there there are some right at this very moment, but there is always some surplus lying around somewhere.

[VK2NR]

Hi,

Thanks for the replies.

Have a look at the PVC trunking for Air Con installations

Terry, I will have a look at the Air con trunking - hadn't thought along those lines.

Ive used 25mm pipe saddles directly onto the cable and screw into the surface u want to run them across.
Fairly simple but effective.

Leigh, I was hoping to stack the cables 2 x 2 rather than all four side by side, but I will keep the 25mm saddle idea as a backup.

Yep, we chuck out hangers for 78/LDF5 all the time. Shame you didn't want them 6 months ago, we had to pay to have a scrappy take them away.
How many do you want? ....

Trash, It's always my luck to turn up just after the horse has bolted. I have 4 runs to be secured at 5 points (just under 1M spacing).
What type of hangers are you usually scrapping? I was hoping to stack 2 x 2, however any hangers would be helpful! PM me if you find any lying around.

On another note, do you find much difference between the Cellflex and Heliax branded cables?

Cheers,
Dave.

[VK2XSO]

No probs... I'll look in my junk box of heliax "accessories" and let ya know. 20 should be easy to manage.
Usually they're just a funny sheet metal omgea shaped clip with a latch. There's also an accessory clamp that sometimes comes with them to support them on a tower.

Cellflex is better. It's a better coax to work with and the connectors and the RFS connectors are so simple and easy to use and they work on both LCF/LDF and/or SCF/FSJ cables where as Andrew connectors only work on Andrew cable. I can put a connector on LCF78 quicker and with less fuss than I can put a PL259 on a piece of RG58

[VK2NR]

No probs... I'll look in my junk box of heliax "accessories" and let ya know. 20 should be easy to manage.

That would be great, thanks!

Cellflex is better. It's a better coax to work with and the connectors and the RFS connectors are so simple and easy to use and they work on both LCF/LDF and/or SCF/FSJ cables where as Andrew connectors only work on Andrew cable. I can put a connector on LCF78 quicker and with less fuss than I can put a PL259 on a piece of RG58

Thanks for the info. I haven't used Andrew Heliax or connectors yet, and after your feedback I will stick with the Cellflex. I find the Cellflex and rapid fit connectors very easy to work with. As you say, very quick to install connectors - especially using the trim tool.

Looking forward to finishing the cabling before the next VHF/UHF field day. It will be the first time with some decent antennas - especially on 23cm.

Cheers,
Dave.

[VK2XSO]

If you've got the tools, even quicker again !
Next thing you'll be doing is using DIN connectors. It really is a shame that most hams no nothing of DIN connectors.
Their performance is even better than N-type connectors and there is soooo many of them going to scrap.
If you have a run of 78 which isn't too flexible at the radio or the antenna you can easily find a pre-made cable SCF34 (FSJ4) with male DIN on one side and N-type on the other.

I just had a look in the hardware box and I found 40 hangers, but they're all LDF4 size.
I'll keep my eyes open for the LDF5 hangers, they're more common than the LDF4 type, I'm sure I'll find some in the next few days.
They're much the same as the ones I have, just their clips are bigger.

[VK2NR]

Thanks Trash.

I have seen the DIN connectors, but never used them. I didn't know that there were so many being scrapped. I could have used some on this project, as there is a tail at both ends of the LCF78. Maybe I should ask around next time, before starting these projects!

Let me know if you find any of the LDF5 size hangers. I could also put eight of the LDF4 size hangers to good use, holding the ends of the antenna tails to the mast, if that is not asking too much. They are currently strapped to the mast with cable ties - works O.K but not ideal.

I am trialling LDF4 sized cable in a large 3 turn "Zebedee" or spring type coil around the rotator - hopefully not exceeding the yield point and causing it to work harden . Others have reported that it works well, but time will tell! It needs to be secured to the mast quite securely to prevent the cable ends moving against the springiness of the cable.

Cheers,
Dave.

[VK2XSO]

They're yours, I'll just find some way of getting them to you.
They're not big and I often know somebody heading your way, else they'll go in the post ok.

I use a goose neck on mine, but the rotator does not turn more than 360 degrees.
http://image85.webshots.com/85/0/34/50/ ... vMa_fs.jpg

[VK2NR]

They're yours, I'll just find some way of getting them to you.
They're not big and I often know somebody heading your way, else they'll go in the post ok.

Thanks Trash. "RF affected persons" are welcome to drop in for a coffee & chat if I am home.
I can also collect them if that makes life easier!

I use a goose neck on mine, but the rotator does not turn more than 360 degrees.
http://image85.webshots.com/85/0/34/50/ ... vMa_fs.jpg

You have me intrigued, but the link isn't working at the moment.

Cheers,
Dave.

[VK6ADF]

I use a goose neck on mine, but the rotator does not turn more than 360 degrees.
http://image85.webshots.com/85/0/34/50/ ... vMa_fs.jpg

You have me intrigued, but the link isn't working at the moment.

Cheers,
Dave.

The link probably works for Trash, but it seems others don't have the required permission to view them.

[VK2XSO]

You'd think I'd have learned that by now.
I usually directly link the picture so that there isn't any other rubbish advertising with it. But the host might has closed the loophole.

This will work.
http://home-and-garden.webshots.com/pho ... 1318qrsvMa

[VK2NR]

Trash,
Nice collection of metal in the air!
What are you using in the goose neck section, RG style coax, Heliax type feedline or something else?

Cheers,
Dave.

[VK2XSO]

It's all heliax. I would not lower myself to use some sort of braided coax !

Ok, there is a piece of RG214 in there and a piece of RG223 and RG11, but none of those through the gooseneck.
The rest is FSJ4, FSJ2 and LDF1 and LDF2.
The feed to the station disaster is LDF4.
I did have a piece of LCF78 running up the tower, but I felt it was overkill. So Ron put it to use as his HF feeder for his wire dipole.

FSJ (or SCF) is very flexible. Older style FSJ4 is as flexible as a piece of garden hose. It's very floppy.

[VK4WDM]

It really is a shame that most hams no nothing of DIN connectors.
Their performance is even better than N-type connectors and there is soooo many of them going to scrap.

Your right! I thought DIN plugs were those semi-circular things that one has on the back of the rig for all sorts of ins and outs. I did not know there are DIN Rf cable connectors

IMO plugs are often the "Achilles heel" of many ham stations where poor performance can be traced to bad plug connections. I think it would be worthwhile for clubs to run education sessions. I would love to learn how to do crimp connections. I still use solder. I should look up You Tube and see if there are some instructional videos.

73

Wayne VK4WDM

[VK2XSO]

There's not a lot of test equipment available to hams for testing connectors.
A couple of years ago there was a fella at Wyong who had a trailer load of boxes with seimens connectors on them and some pretty lights.
He had no idea what they were or how to use them.
I offered to buy one for $5. He figured they were worth more. They were, but only if you knew what they were
So for the $5 price tag, I offered to show him how they were used.

They were connector percussion testers. To test the quality of the cable a DC carrier was passed down the cable and any modulation coming out the other end is
amplified to a speaker. The connectors are then tapped with a nylon donger. Or the handle of a screwdriver if you were slack.
Any problems were quickly heard in the speaker.

Another method of testing is insulation testing. A megger is basically used to test the core to shield. This is however a really stupid idea in my opinion.
The cable is often charged up like a nice high voltage capacitor and if it is not discharged or ever discharged properly, when it is connected to any equipment, that equipment is then broken.

Insertion and return loss testing is the best method.
This is an example.
http://home-and-garden.webshots.com/pho ... 1318sMsVET
A 1m section of RG59 is being tested.
The top graph is insertion loss and the bottom is return loss (SWR)
This plot says a lot about cables and transmission lines. It's a very good plot for teaching.

Another test of high quality connections is PIM testing.
Any dust in the connection will effect the PIM test. But this is overkill for ham radio applications.
I regularly test connectors and their intermod products are typically -150dBc.
Obviously, these are not PL259's

[VK6ADF]

I would love to learn how to do crimp connections.

Get a crimper and give it a go. I don't think you would find it as hard as you imagine. It's basically the same as the solder type, you still have to solder to the pin (unless you use the spring type) and then the crimp sleeve slides down over the braid and is crimped so it traps the braid between the sleeve and the main body of the connector.

[VK2XSO]

You might find that almost all of the crimp type connectors (BNC, TNC and N-type) are also designed to have their center pins crimped as well.
Though manufactures still put a small hole on the side of them so they can be soldered if required.

[VK6ADF]

I tried that once and made a mess of it so I always solder the pins on now. I once bought a ready made LMR400 lead and had to change a plug on one end and when I dissected it I found the pin was neither crimped nor soldered...and it was not one of the spring type. I think they either forgot or expected the tight fit to be enough. I was not impressed.