Mast options for a Gain Master?

[K7RDN]

I am just starting to get back into CB's. I was really heavy into them in the 70's-80's. Had a Super Penetrator and a Moon Raker IV along with a Tempo One base and several different mobiles.
I am seriously thinking about purchasing a Gain Master and mounting it on a gable side of my house with the mast secured to the ground, at least 2-24" wall stabilizers (offset for eave overhang) and another stabilize at the gable peak, about 20 foot above the ground. I then want to extent the mast about 10' above the peak without any guy wires and the GM mounted to the top of the mast. I have been looking at the Rohn 9H50. Will this work? Is there a better way to go? What other options do I have? Is there a cheaper way to go?

Being a newbie, Thanks in advance for your advice and suggestions.

 

[mackmobile43]

That's a nice pushup pole and being a rohn product you can be sure of it's quality as for me I use 1 1/2'' galvanized pipe from a recycled chain link fencing project which is pretty heavy gauge metal, it came in 21' lengths which I used one full section and half of a second.

I drove a 6' section of the same into the ground with the reduced end up to connect the following section and so on and that is secured to the upper wall, it's been up for several years and I'm not suggesting you do like I have, sounds like you have a fairly good mounting scheme but just letting you know this material is strong enough for this type of installation with all gp antennas.

Here's a picture of it on a "windy" day.lol

 

[CDX-007]

I am just starting to get back into CB's. I was really heavy into them in the 70's-80's. Had a Super Penetrator and a Moon Raker IV along with a Tempo One base and several different mobiles.
I am seriously thinking about purchasing a Gain Master and mounting it on a gable side of my house with the mast secured to the ground, at least 2-24" wall stabilizers (offset for eave overhang) and another stabilize at the gable peak, about 20 foot above the ground. I then want to extent the mast about 10' above the peak without any guy wires and the GM mounted to the top of the mast. I have been looking at the Rohn 9H50. Will this work? Is there a better way to go? What other options do I have? Is there a cheaper way to go?

Being a newbie, Thanks in advance for your advice and suggestions.

I've noticed my Sirio Gain Master does not like to be less than ~18' (½ wave) above anything, even my 80m inverted vee (which is directly below it) causes a noticeable drop in performance, locally.

What about using a 3 section push-up mast on the roof and guying with dacron covered kevlar line? (Which is invisible to RF)

You'll probably see a significant increase in your local signal strength by having the extra height above ground.

 

[K7RDN]

I've noticed my Sirio Gain Master does not like to be less than ~18' (½ wave) above anything, even my 80m inverted vee (which is directly below it) causes a noticeable drop in performance, locally.

What about using a 3 section push-up mast on the roof and guying with dacron covered kevlar line? (Which is invisible to RF)

You'll probably see a significant increase in your local signal strength by having the extra height above ground.

I am about ready to pull the hammer on a Rohn R-9H50 which extends to 34' in length, that is about 14' higher than the peak of my roof, however mounting it on the gable side of my house, I can't string any guy wires. I am afraid that extending the mast to full length and having 14' of mast without guy wires might be asking for trouble, but I thought that 10' would be ok. Of course the GM would extend above the mast another 20 some feet or so.

I just put a new roof on my house and don't really want to make any protrusions into it for guy wires.

What are your thoughts? I appreciate the input! Ordered the GM from H&Y Electronics on Sunday via EBay.

 

[CDX-007]

As far as drilling for guy bolts, I drilled out just past the wall into the overhang, underneath I added a pair of 2x4s screwed together as a 4x4 between a couple 2x4 truss extensions in the overhang and it's strong as heck!

After drilling the hole for the guy bolts (at an angle toward the wall - about a 45° - so the guy wire is pulling the guy bolt crossways instead of directly on the threads - that's how they pull out!) I pumped a bunch of Henry's never harden down into the hole until full then when I immediately screwed the guy bolt into the hole a bunch oozed out leaving a great seal all around the guy bolt and a mound above the shingle which sealed it fully.
I may redo it in the future and use machine thread guy wire bolts which will go through the 4x4s and have large washers and nylocks to tighten in place.

If you're in a single-story that 4-section on the roof would net you about 48'-50' at the bottom of the Gain Master, over 70' at the top, and you'd love the ears at that height!

If you decide to take on the challenge, use 5/32" dacron covered kevlar line for guying or a ton of insulators for the top two 9' sections if metal guy wire is used. Add the 1st insulator about 2" from the mast, then break it up about about every 6' until you've used 4 insulators per wire. 2" / 6' / 12' / 18'.

That's 12 insulators total for the top section if you guy 3 ways per section.

Then you only need 3 insulators per wire at the top of the 2nd section down in order to keep them insulated 18' below the Gain Master, or 9 more total if you guy 3 ways, 2" / 6' / 12'.

How high is the typical max wind speed in your area? If it's fairly high then you may want to guy it 4 ways per section.

Use at least 6/20 guy wire & ~1.5" ceramic "egg" insulators, making sure you interlace both guy wire ends through the insulator so if it broke you'd still have two loops of guy wire interlaced through each other.

On the ground it wouldn't do poorly, but on the roof it would 'sing'! - If you do chicken-out & keep it on the ground, try to add a couple feet of some sort of pole so the bottom of the SGM is at least 36' above the ground if possible.

- I have a 5 section push-up on top of this 20' roof, and it's an old 1953 thick-wall Rohn that's as heavy as seven freight cars to lift with hard line, 20 guy wires and antenna, but it's sure worth it when it's all the way up to ~90' to the top!

It's so high "I can [hear] Russia from my house..."

...

 

[K7RDN]

We will see in extreme conditions 50 to 60 MPH wind gusts, but rarely. Yes, I have a single story home with a daylight basement. I would use 4 guy wire tie downs if I do decide to mount it on the roof. Sorry I don't understand how you are mounting the 2x4 for the guy wires. If I did mount it on the roof I was thinking about getting some "Eye" screw and screwing them into the trusses. With your system does the guy wires go over the eves and attach to the side of the house? If so, it seems like that would wear the guy wires on the roof edge.

Just re-read your post, are you saying that you mounted the 2x4's to the fascia (trim board around the tails and overhangs (lookouts) of trusses) with the "eye" bolts mounted on top of the 2x4's so that they stick above the roof? Sorry for the terminology, but I am a Construction Guy.

How hard is it to adjust the SWR on the GM? I assume that I will have to put it up and take it down a few times to get the SWR right, correct? Seems like I would need at least 4 people to help put it up.

I just had foot surgery and it will be a couple of months before I am able to get around good enough to put the GM up. Right now, I'm not looking forward to climbing on my roof.

Where is the best place to get the Kevlar guy wire? From your post, am I right in assuming that if I use the Dacron covered kevlar I don't need any insulators, correct?

If I went with mounting it off the gable to the ground like I had first thought, with the mast being unsupported (no guy wires) 14 to 16 foot above the last support, do you think the mast would handle it?

 

[CDX-007]

We will see in extreme conditions 50 to 60 MPH wind gusts, but rarely. Yes, I have a single story home with a daylight basement. I would use 4 guy wire tie downs if I do decide to mount it on the roof. Sorry I don't understand how you are mounting the 2x4 for the guy wires. If I did mount it on the roof I was thinking about getting some "Eye" screw and screwing them into the trusses. With your system does the guy wires go over the eves and attach to the side of the house? If so, it seems like that would wear the guy wires on the roof edge.

Just re-read your post, are you saying that you mounted the 2x4's to the fascia (trim board around the tails and overhangs (lookouts) of trusses) with the "eye" bolts mounted on top of the 2x4's so that they stick above the roof? Sorry for the terminology, but I am a Construction Guy.

How hard is it to adjust the SWR on the GM? I assume that I will have to put it up and take it down a few times to get the SWR right, correct? Seems like I would need at least 4 people to help put it up.

I just had foot surgery and it will be a couple of months before I am able to get around good enough to put the GM up. Right now, I'm not looking forward to climbing on my roof.

Where is the best place to get the Kevlar guy wire? From your post, am I right in assuming that if I use the Dacron covered kevlar I don't need any insulators, correct?

If I went with mounting it off the gable to the ground like I had first thought, with the mast being unsupported (no guy wires) 14 to 16 foot above the last support, do you think the mast would handle it?

One thing you'll appreciate about the SGM is it's slight wind load compared to most other 5/8, even to the Imax it seems less top-heavy & wobbly.

I screwed two 2x4s together and screwed them in place under the overhang up against the fascia, then went down through the top of the roof, outside the wall with the eye screws. I would have preferred to use bolts but I didn't have them handy like I had the eye screws. I'll probably upgrade them in the future.

Going up 15' or so without guying is pushing it, in 50-60mph I'd fear the worst. No SWR adjustment is necessary.

Go the extra effort and reap the rewards of increased performance, you will love the performance at ~50'!

You may find guy wire & insulators less expensive, but the line can be found on-line. I'll try to finds the website for you.

 

[K7RDN]

Thank you! I appreciate your help. I've looked a little for the Dacron covered Kevlar guy wire but couldn't find any.

I have started a new post "Setting up a Sirio Gain Master, have questions!" may you have some answers to my questions.

Thanks again, BB