Antenna Replacement on 100 Foot Rohn 25G (Full)

The antenna was replaced for the New Bern, NC Amateur Radio Club. I removed an old Station Master that was designed for 155 MHz, so it was a poor performer on 2-meters. The VSWR was terrible, so I rebuilt a dipole array that I removed from another site. The club representative thought that 4 elements would be too much wind-load for the 25G, so I only used two elements and made a new phasing harness. The coax was OLD, but it was still usable. You can see the old PVC jacket is completely gone... A quick VSWR check showed 70 Watts out after the duplexer and zero reflected. Range tests are still being performed, but it is exceeding expectations. Current ERP is 180 Watts, so once the range tests are complete, I'll do a final alignment to dial in the power so it is not transmitting further than it can receive. Sorry about the whistling, singing and talking to myself.
The new antenna is a modified Phelps-Dodge with elements cut for 146 MHz. I used a combination of 75, 50 and 35 Ohm coax for the phasing harness to achieve a 50 Ohm Match at the feedpoint. I also bent new elements as the old ones were too short.
Repeater is a Harris MASTR III VHF (150-174) that I modified for 2-meters. I added some brass to the tuning slugs on the receiver front-end and changed a few components. After the mods, the receiver opened squelch at -116dB and it put out 125 Watts. I turned it down to 95 Watts for initial testing.
Enjoy!

[@richpayton7162]

For several years I climbed 54', 102', 200', and 304' scaffold towers used to hold weather instrumentation sensors on a 98,000 acre Air Force Base. I had grown to feel fully confident in my safe climbing skill, but this video made me feel rather queasy, A lot of that was due to fish eye distortion of the camera lens and how the view through it affects the mind. This climb was not for the faint at heart, which at this stage of life includes this ex rigger. Bravo!

[@CarrotDugTooDeep]

It wasn't too bad. As you said, the camera made it look worse than it was.

[@marklowe7431]

I'm just amazed it could take the weight of your nuts. Brave man but also noticed good safety. Interesting video.

[@sjc62759]

No, not the zip ties... use electrical tape to fasten the coax connection loop to a tower leg or mast.

[@w1klmster]

Well done. The phone call afterward though; class act!

[@CarrotDugTooDeep]

Yeah, she always worries about me climbing, so I always tell her when I'm down.

[@g1egz]

What phone call?

[@CarrotDugTooDeep]

@@g1egz I called my wife when I got down. I used an app called Zello, which is like a walkie-talkie. On the original recording, you can hear her answer me, but on the upload, she is almost inaudible.

[@ronmondgock9440]

Nice job.....Ron in Nevada......

[@applejacks971]

Nope. This made my feet so sweaty I had to take my socks off. I wouldn't make a good tower climber!

[@y2kalob1]

Hello fello tower dog. Hey buddy I don't mean to sound like a safety Sally but I want to point out some things I can see wrong. Ive done this for a while now and built many of those Rohn25g towers. I know first hand about building them under spec and the dangers that can occur. So I hope my words help. Your obviously a hard working intelligent man so the industry needs the likes of you. First off that tower is obviously built out of specs. Some worry here but many are built out of spec. That is wire rope used as guy wire. Which has slipped at some point or was never plumed in the first place. Thats why we see its crooked from the video when you shoot the camera up the tower. You NEEEED to inspect those GUY wire points before climbing. Re plum tower and check tension before climbing. Second thing I see is your clipping off to the lattice. Ive seen many tower sections with broken welds. They can hide under the galvanizing. Always clip off to the vertical on these. You also need to upgrade your Y lanyard to one that has rated gates. Hope this helps buddy. stay alive

[@WinZard]

I think its from the wide angle fish eye lens...….

[@frankthetank3342]

Were the gates not properly rated?

[@krzysztofszmel7503]

Troche jest zle ,bo nie widac co robi.Zle byla ustawiona kamera...

[@frankthetank3342]

Why use rebar hook on right side to bracing? To keep hook in straight line, in case the left one on main tube snaps due to angle of the hook?

[@matforsbon]

Just guessing because they are smarter than you.

[@frankthetank3342]

@@matforsbon apparently smarter than you, as well. Or, they have some kind of logic behind it. Typically, you attach to the main tubes/rods, not to z-ladder or bracing.

[@bikerush1]

Flexible conduit housing the coax

[@Tripring2000]

There isn’t enough money in the world that would have paid me to climb that tower. Especially with the guys as in bad shape as they were.

[@dougtaylor7724]

Not the sturdiest of towers is it. I hate to see the loose guys wiggling when you get almost to the top. Nice job Sir.

[@alexandrmelnikov2953]

And what?

[@whuffer5103]

38:43, was that "When a Man Loves A Woman"?

[@whuffer5103]

1:05:48 Rolling Stones Miss You

[@whuffer5103]

I swear this dude was me in a different dimension

[@CarrotDugTooDeep]

You got it! I whistle, a lot. And when I'm not whistling, a song of some sort is playing in my head, either something that I made up or songs like these that I was whistling.

[@CarrotDugTooDeep]

@@whuffer5103 I think there were some other Rolling Stones songs too. I do remember whistling "Dancing With Mr. D" on that day...lol

[@charleneaquilar791]

sir what is the size of pipe?

[@CarrotDugTooDeep]

2" aluminum pipe.

[@Dallas-Rife-UDX-347-Tennessee]

Worst tower design ever to manually climb .

[@CarrotDugTooDeep]

I have seen way worse. At least this type has horizontal bars to stand on. The old BX design only had stamped crossed braces, which are awful to climb and work on.

[@Dallas-Rife-UDX-347-Tennessee]

@@CarrotDugTooDeep I never been a climber Never much paid attention until the last few years since I put my 40 foot Rohn 25 up . The guy that climbed mine has a tower in his yard called called an American Tower I think 🤔. It pretty much has real ladder rungs welded onto it as the bracing Very genius . You’d think Rohn woulda got on board years ago but their engineers aren’t the ones putting their feet in pain standing on tiny rods

[@CarrotDugTooDeep]

@@Dallas-Rife-UDX-347-Tennessee Check out those BX towers that don't have horizontal braces. They are plain awful. Happy Thanksgiving!