Attempting to make the Diamond D-130J Vertical Antenna better

[CorwinScansNM]

Hi everybody viewing this thread here,

I am looking for some very useful information for making my Diamond D-130J Vertical Antenna better & more solid by upgrading the current 8 grounding elements on this external scanner antenna to either solid Aluminum round rods or solid Stainless Steel round rods instead of the cheap hollow filled grounding elements that are currently on this antenna & that came with it. This all to make it more rugged/solid & improve frequency receiving abilities with this antenna for me & my digital public safety scanner.

Now what I need help with is, choosing the best type of solid metal grounding elements. I am not sure which of the 2 solid metals that I mentioned above if either is going to be the best to install on the Diamond D-130J for the best or better frequency signal receiving coverage to replace the 8 hollow grounding elements that came with the antenna & are currently installed on it; but that I am not fond of or happy with? Thus, to change them out & install better being solid metal grounding elements/rods instead of the current hollow ones that came with it!

Please help & advise if I should buy & use solid Aluminum round rods or Stainless Steel round rods for this replacement plan of the grounding elements on this antenna.

THANKS!

 

[mmckenna]

Stainless would be preferred.

You could buy rod and thread it, but stainless steel is harder to machine that steel and you'll need the right tools.
Aluminum would be a lot easier to machine, but it's soft and probably won't last as long. Also, using aluminum with whatever the center hub is made out of might result in corrosion issues.

I'm not sure what the thread size is on those, you'd need to figure that out, might be metric. Anyway, probably the easiest way to do this is to buy stainless steel threaded rod (aka: All-Thread) . Won't be inexpensive, but it'll last a long time.

For a quick idea of pricing, here's stainless steel 4x40 all thread rod

3 feet long:
https://www.amazon.com/Threaded-Rod...1493534553&sr=8-8&keywords=4x40++threaded+rod

2 feet long:
https://www.amazon.com/Threaded-Rod...1493534553&sr=8-9&keywords=4x40++threaded+rod

4x40 probably isn't the right size, like I said, it might be metric.




Alternatively, you could find the right size brazing rod, or something similar, and just put it up the inside of the hollow rods you already have. That'll give them some more strength, but corrosion might be an issue.

 

[Ubbe]

RF current flows on the surface of the rods, not inside them. Making them solid or using steel wont change anything in receiving capabilities.

Mixing steel and aluminum are probably not a good idea. It could create a galvanic coupling acting like a battery and corrode the antenna very quickly when the air is moist.

If you have problem with the aluminum tubes breaking then you could change them to solid rods.

/Ubbe

 

[prcguy]

I had a Radio Shack Discone that is notorious for the thin SS elements working loose from their crimped threaded parts. I used 3/16" dia aluminum rod, drilling out the brass hub and threading the elements and hub with whatever the nearest thread size was. It might have been 10-24.

I had to use vice grip pliers to screw in the elements but the antenna was much more sturdy and solid when it was all done. Its a good idea to paint the antenna and seal up the threads and to use something to avoid galvanic corrosion from dissimilar metals like Burndy Penetrox.
prcguy

 

[phask]

I'll confirm they are metric - but I don't know what thread. I had to re-thread one once.

Not to hijack the thread, but I have one that is many years old. Performance seems to have deteriorated - any suggestions?

I thought of removing all the radials, wire brushing etc.

Is there anything speial with that pigtail coax they come with? The one that goes inside the mast tube.

 

[prcguy]

I would suspect your coax over the antenna, not much to go wrong with the antenna unless you see something obvious like elements missing, etc. Coax is another story with moisture and connector problems.

I just took down a couple of antennas off my tower that were not performing well and found I skimped on weatherproofing connectors. I had N connectors mating with N barrel adapters where water ran out and the insides had fuzzy green stuff shorting out the center pin. I was probably in a hurry when they went up to test something and never went back to finish the weatherproofing.
prcguy

I'll confirm they are metric - but I don't know what thread. I had to re-thread one once.

Not to hijack the thread, but I have one that is many years old. Performance seems to have deteriorated - any suggestions?

I thought of removing all the radials, wire brushing etc.

Is there anything speial with that pigtail coax they come with? The one that goes inside the mast tube.

 

[phask]

I would suspect your coax over the antenna, not much to go wrong with the antenna unless you see something obvious like elements missing, etc. Coax is another story with moisture and connector problems.

I just took down a couple of antennas off my tower that were not performing well and found I skimped on weatherproofing connectors. I had N connectors mating with N barrel adapters where water ran out and the insides had fuzzy green stuff shorting out the center pin. I was probably in a hurry when they went up to test something and never went back to finish the weatherproofing.
prcguy

Yeah - probably. It was old RG8, checked OK with a VOM - but who knows. I tried it with a 10' jumper that's old but always been inside. Will need to do some more checks.

Of course over the years stuff has migrated from 40 mhz and 155 to 800.

Hope to check it out and attic mount.

 

[CorwinScansNM]

RF current flows on the surface of the rods, not inside them. Making them solid or using steel wont change anything in receiving capabilities.

If you have problem with the aluminum tubes breaking then you could change them to solid rods.

/Ubbe

OK, Solid rods being pure Aluminum or pure Stainless Steel rods to replace the cheap Aluminum tube rods that came with this antenna?

 

[CorwinScansNM]

Stainless would be preferred.

You could buy rod and thread it, but stainless steel is harder to machine that steel and you'll need the right tools.
Aluminum would be a lot easier to machine, but it's soft and probably won't last as long. Also, using aluminum with whatever the center hub is made out of might result in corrosion issues.

I'm not sure what the thread size is on those, you'd need to figure that out, might be metric. Anyway, probably the easiest way to do this is to buy stainless steel threaded rod (aka: All-Thread) . Won't be inexpensive, but it'll last a long time.

For a quick idea of pricing, here's stainless steel 4x40 all thread rod

3 feet long:
https://www.amazon.com/Threaded-Rod...1493534553&sr=8-8&keywords=4x40++threaded+rod

2 feet long:
https://www.amazon.com/Threaded-Rod...1493534553&sr=8-9&keywords=4x40++threaded+rod

4x40 probably isn't the right size, like I said, it might be metric.




Alternatively, you could find the right size brazing rod, or something similar, and just put it up the inside of the hollow rods you already have. That'll give them some more strength, but corrosion might be an issue.

Thanks so much for the info & answer to my question regarding my plan to do this soon. I just have to take the scanner antenna down in order to temporarily remove one ground element so that I can measure its width & length so that I make sure to get the same size for the new solid stainless steel elements which I am probably going to purchase on eBay from this seller who seems to be selling a lot of good varieties, sizes & quantities of stainless steel round rods at pretty good prices too.

highdesertmartin on eBay

This seller also mentions for most of his Stainless Steel round rod listings that, "Cut ends have been ground" which seems good in my opinion for using them as antenna ground elements.

 

[cmdrwill]

bhighdesertmartin on eBay may be a good source for some of the parts to make EMCOM portable antennas.

 

[mmckenna]

Thanks so much for the info & answer to my question regarding my plan to do this soon. I just have to take the scanner antenna down in order to temporarily remove one ground element so that I can measure its width & length so that I make sure to get the same size for the new solid stainless steel elements which I am probably going to purchase on eBay from this seller who seems to be selling a lot of good varieties, sizes & quantities of stainless steel round rods at pretty good prices too.

highdesertmartin on eBay

This seller also mentions for most of his Stainless Steel round rod listings that, "Cut ends have been ground" which seems good in my opinion for using them as antenna ground elements.

Length isn't super critical on the ground plane rods. You don't want them any shorter than they are now, but longer is OK.

In this case, the terms "ground" have two different meanings.
What the seller means by "ground" is that after the threaded rod has been cut, the ends are ground smooth, and usually rounded off/tapered a bit to help them thread easier. This you do want.

Your use of "ground" means the earthed part of the antenna that is connected to the outer shield of the coaxial cable, and hopefully a proper grounding system.

 

[prcguy]

My old Diamond DJ-130 had elements that threaded into the hub, are yours threaded or held in with set screws? If you are going threaded I would avoid stainless steel elements as they are really hard to thread.
prcguy

Thanks so much for the info & answer to my question regarding my plan to do this soon. I just have to take the scanner antenna down in order to temporarily remove one ground element so that I can measure its width & length so that I make sure to get the same size for the new solid stainless steel elements which I am probably going to purchase on eBay from this seller who seems to be selling a lot of good varieties, sizes & quantities of stainless steel round rods at pretty good prices too.

highdesertmartin on eBay

This seller also mentions for most of his Stainless Steel round rod listings that, "Cut ends have been ground" which seems good in my opinion for using them as antenna ground elements.

 

[mmckenna]

My old Diamond DJ-130 had elements that threaded into the hub, are yours threaded or held in with set screws? If you are going threaded I would avoid stainless steel elements as they are really hard to thread.
prcguy

Yeah, I agree, that's why I recommended all thread rod. Most average Joes don't have the right tools to machine stainless. The all thread will cost a bit more than plain rod, but it'll still be cheaper than trying to machine it yourself.

 

[CorwinScansNM]

My old Diamond DJ-130 had elements that threaded into the hub, are yours threaded or held in with set screws? If you are going threaded I would avoid stainless steel elements as they are really hard to thread.
prcguy

Hi and thanks for that question. My Diamond D-130 that I received & purchased does not have the ground elements that are threaded but instead are only held in by the silly cheap & tiny pointed hex wrench screws. I was in fact hoping for the threaded ground elements that you just simply turn & tighten when I purchased & received my Diamond D-130 which was less than a month ago today. However, I was not that lucky unfortunately & must have received the cheaper design of this scanner antenna that is not built that well anymore!

My new Stainless Steel ground elements are not going to be threaded. Instead, I am going to have to find that exact thread & size of set screws in normal flat screws at my local hardware store instead of the pointed hex wrench screws that came with the original antenna. This to make sure that the new upgraded Stainless Steel elements are held in very well & better than they would be with the 8 tiny pointed hex wrench screws that are used for the current ground elements that are on the Diamond D-130.

 

[CorwinScansNM]

bhighdesertmartin on eBay may be a good source for some of the parts to make EMCOM portable antennas.

I can't seem to find bhighdesertmartin on eBay! Can you post a web link to his eBay listings or profile? Nevermind!! I think that this is the same seller that I posted earlier but with a letter b in the eBay username for some strange reason? Same seller though I think.

 

[CorwinScansNM]

What about using Zinc-Plated Round Rods as ground elements on this scanner antenna? How would that work or is it not a good idea? I am just ruling out that as possibly another option to replace the hollowed out ground elements that are on this antenna.

3/16 in. x 36 in. Zinc-Plated Round Rod-802287 - The Home Depot

 

[mmckenna]

I'd stick with aluminum or stainless.
Zinc plating might not last very long if there is any flexing of the elements.

 

[CorwinScansNM]

I'd stick with aluminum or stainless.
Zinc plating might not last very long if there is any flexing of the elements.

Thanks for the info & heads up there on the Zinc Plated Stainless Steel round rods. It was just another option that I was considering but will not now taking your kind advice that you provided. I think that I am finally going to go with eBay item number: 201511314014

(304 STAINLESS STEEL ROUND RODS) that are 4 inches longer than the current ground elements that came with the D-130J Scanner Antenna, which I found some good information on the web about the (304) grade Stainless Steel as well as the (316) grade Stainless Steel. I will share the link below for my helpfulness to you & others now & in the future.

304 vs 316 Stainless Steel | Reliance Blog

 

[mmckenna]

Thanks.
Yeah, I work with stainless steel fairly frequently, however I have a hard time remembering which is which.

Where you are in New Mexico, the 304 should be just fine.
I'm right on the coast, in fact I have radio sites a few hundred feet from the Pacific Ocean. 316 stainless is usually what we try to use. Occasionally our network guys will hang a point to point radio and use cheap hardware. We usually end up having to torch or sawzall the hardware off .

Good point in that article is that "Stainless" steel is a misnomer. Stain resistant is more appropriate.

On the professional side, any exposed hardware is almost always stainless. We do use some galvanized hardware, but it's rare.
I often pick up the stainless hardware that gets dropped off the towers. I've probably got 50+ pounds of stainless steel nuts, bolts, washers, etc in my garage. I do entire projects at home in stainless simply because I have the stuff.

 

[phask]

Thanks.
Yeah, I work with stainless steel fairly frequently, however I have a hard time remembering which is which.

ds of stainless steel nuts, bolts, washers, etc in my garage. I do entire projects at home in stainless simply because I have the stuff.

Would/should NoOx be used on these? I see some surface corrosion or reaction between the base (or whatever one calls that piece) and both the threaded top elements and the screw held radials. I think that base may be brass with chrome plating.

I plan on wire brushing the "holes" and cleaning all the elements. Mine will be remounted inside so little issue - was just curious.

I've always used it on aluminum and copper.

To the OP all those thread are metric - if you replace the allen set screws , which are designed to hold better than a flat ended bolt, make sure they don't have burrs , etc. It's east to strip them out as well, and round out the allen screws.