Diamond Antenna D-130J

[K4EET]

I am considering the Diamond Antenna D-130J which has a receive coverage range of 25 MHz to 1300 MHz that matches the Uniden BCD536HP frequency span. Two questions:

1. Does anybody have experience with this antenna? Pros/Cons/Comments?

There was a WTB post about this antenna at:
http://forums.radioreference.com/old-classifieds-archives/114653-wtb-diamond-d-130j-discone-antenna.html
but no discussion of the antenna.

2. Are there comparable antennas in the $100 price point worth looking at?

This antenna can be found at:
Diamond Antenna D-130J: Ham & Amateur Radios - Equipment, Parts and Supply | AES

Thanks for your time and assistance!

73 (best wishes in ham lingo), Dave K4EET

 

[NDRADIONUT]

Diamond D-130J discone Product Reviews

 

[mmckenna]

I scored one for free many years ago. Seems built well enough. It's been up in the air for almost 10 years now. Hasn't lost any elements. No signs of corrosion.
Stellar performer, it isn't. While it does have a wide usable bandwidth, the zero gain nature of it makes it limited in value.
I'm using mine right now as a temporary 2 meter VHF antenna. Works OK. It's at about 30 feet off the ground, feeding it with about 40 feet of LMR600.

If you are going to be purchasing a new one, try to find one with the N connector. Makes a bit more sense when you are looking at frequencies above 400MHz.

 

[ridgescan]

It does the job. Mine gives decent performance, not remarkable performance. The great thing about it is its durability like McKenna said. You can stick it up there in the worst elements and never give it another thought. All stainless and aluminum groundplane elements.
Mine receives up to 50 miles vhf-lo, 60 miles uhf, and about 50 miles vhf-hi. 800 I reliably receive the whole of San Francisco, but Oakland at only about 9 miles from my QTH I cannot hear. In the airband, I can hear Travis AFB's ATIS at 49 miles. Not bad for air.
Mine is about 8 years old and still like new.

 

[K4EET]

Thanks for the replies folks. And yes, eHam.net Home - Amateur Radio (Ham Radio) Community Site is a great reference. I posted in RadioReference.com - Scanner Frequencies and Radio Frequency Reference in case somebody else was wondering the same thing and especially since I could find no other posts discussing this antenna other than the WTB post. Thanks again for the replies!

73, Dave K4EET

 

[n3ouc]

Hi Dave,
Like MMCKenna stated, get the one with the "N" connector. I believe the number is D-130NJ. I have that model and it works, but like others have mentioned it isn't a stellar performer. They are what you might want to call a very reliable antenna that will last forever.
Mike

 

[K4EET]

Hi Dave,
Like MMCKenna stated, get the one with the "N" connector. I believe the number is D-130NJ. I have that model and it works, but like others have mentioned it isn't a stellar performer. They are what you might want to call a very reliable antenna that will last forever.
Mike

Thanks for your comment es 73, Dave K4EET

 

[PBman]

Love Mine !!!

 

[n5ims]

I am considering the Diamond Antenna D-130J which has a receive coverage range of 25 MHz to 1300 MHz that matches the Uniden BCD536HP frequency span. Two questions:

1. Does anybody have experience with this antenna? Pros/Cons/Comments?

There was a WTB post about this antenna at:
http://forums.radioreference.com/old-classifieds-archives/114653-wtb-diamond-d-130j-discone-antenna.html
but no discussion of the antenna.

2. Are there comparable antennas in the $100 price point worth looking at?

This antenna can be found at:
Diamond Antenna D-130J: Ham & Amateur Radios - Equipment, Parts and Supply | AES

Thanks for your time and assistance!

73 (best wishes in ham lingo), Dave K4EET

My recommendation is to pretty much ignore the frequency range your scanner will cover and concentrate on the frequency range you actually will monitor. Chances are you'll find that you'll never tune below the 140 - 150 MHz range. Perhaps even only monitor the 700 & 800 MHz bands. By getting an antenna that covers where you monitor instead of where you might monitor if there was something worth hearing, you can get a much better antenna than a run-of-the-mill no gain DC to Daylight antenna.

As a current ham, you may even already have a good antenna. My dual band VHF/UHF ham antenna works pretty well on the few agencies in that range (and many on the 700/800 MHz band). I also have an 800 MHz antenna for the majority of systems that are on that band. I've tried to find signals on the VHF-Low band (30 - 60 MHz) using my discone that covers that band, but frankly there's nothing there worth the effort to monitor. This is confirmed using my county page in the RR database.

For general scanning, I typically use a Larsen tri-band mobile antenna (150/450/800) on an NMO mag mount on a 4 drawer steel filing cabinet. Covers pretty much everything I want to monitor and is inside so no need to unplug during lightning storms.

 

[K4EET]

My recommendation is to pretty much ignore the frequency range your scanner will cover and concentrate on the frequency range you actually will monitor. <snip>

I've tried to find signals on the VHF-Low band (30 - 60 MHz) using my discone that covers that band, but frankly there's nothing there worth the effort to monitor. <snip>

Rather than monitoring a relatively few systems, I actually do listen to law enforcement using VHF-Low Band through the 23 cm Ham Band. In our area, there is a lot of activity. I have 74 FLs that I shuffle through. I listen to one system for a while and then go to another.

For general scanning, I typically use a Larsen tri-band mobile antenna (150/450/800) on an NMO mag mount on a 4 drawer steel filing cabinet. <snip>

That is basically what I have but it is a Hustler on a file cabinet. LOL

73, Dave K4EET

 

[mmckenna]

Hard to beat a dedicated low band antenna. Nothing can really replace having a proper antenna for low band.
I'd agree with N5IMS, discones like these are usually poor low band performers. They often have a base loaded whip on them as a way to "claim" low band coverage, but shortening a whip usually results in poor performance down that low.

Really depends on what your local signal levels are. If the signals you want to listen to are strong enough, then this will work. If anything is on the fringes, you'll likely be disappointed.
If I was doing this, I'd probably try the discone, but I'd also probably install a dedicated low band antenna, a dual band VHF/UHF antenna and something dedicated to 700/800 MHz.

With zero gain coupled with feed line losses, you are really stacking the deck against you. Especially on the higher frequencies. Then again, if all you have space for is a single antenna, then maybe this is a good compromise.

 

[K4EET]

<snip>Then again, if all you have space for is a single antenna, then maybe this is a good compromise.

Good points all around. Ideally, I would do what you say. I am somewhat limited in "space" based on the fact that I am in a wheelchair and physically a semi-quadriplegic and do not want to over-burden my friends with a real antenna farm. Most signals are fairly strong on my indoor mag-mount antenna for VHF/UHF so an outside discone, even if unity gain or somewhat less since the elements are not quite vertically polarized, should do better than my indoor antenna since it will be outside the aluminum siding and trice as high AGL (above ground level). I do wish I could "do it right" but I think it would be too much for my friends...

One question though, if I did have 3 or 4 dedicated antennas to specific bands with gain for each antenna, how would you combine them into one feed for the scanner? A combiner would be quite expensive.

73, Dave K4EET

 

[AK9R]

As mentioned, the D-130J is not really designed for low-band VHF. The additional whip that comes out the top of the antenna is an add-on element intended to provided low-band coverage, but it's a compromise.

On the D-130J that I have, the long cone elements are tubular. They are light enough to make me think they are aluminum, though they could be thin-wall stainless steel. The ends of these elements that go into the "base" of the disk are filled with a soft metal, probably aluminum or zinc. These elements are attached to the base by screwing set screws into the side of the tubing. The filler material in the end of the tubing provides something for the set screws to seat against (if the filler wasn't there, the set screw would probably flatten the tube). Anyway, I've always been concerned about this arrangement as it just seems a little hokey to me. I wonder how many D-130Js that have been in the air for a long time have lost one of their cone elements?

 

[K4EET]

As mentioned, the D-130J is not really designed for low-band VHF. The additional whip that comes out the top of the antenna is an add-on element intended to provided low-band coverage, but it's a compromise.

On the D-130J that I have, the long cone elements are tubular. They are light enough to make me think they are aluminum, though they could be thin-wall stainless steel. The ends of these elements that go into the "base" of the disk are filled with a soft metal, probably aluminum or zinc. These elements are attached to the base by screwing set screws into the side of the tubing. The filler material in the end of the tubing provides something for the set screws to seat against (if the filler wasn't there, the set screw would probably flatten the tube). Anyway, I've always been concerned about this arrangement as it just seems a little hokey to me. I wonder how many D-130Js that have been in the air for a long time have lost one of their cone elements?

There seems to be several different styles of discones out there. Some are made by Comet or Diamond and others by Tram. Some seem to have solid stainless steel elements. Not sure how one could make sure of which elements to get...

73, Dave K4EET

 

[K4EET]

One other thing I could do is this. Just take one of my old Ringo Ranger IIs for 146 MHz and stick it outside as a scanner antenna. While it would only be matched to 146 MHz, it would be a big piece of aluminum that would probably receive better than my file cabinet-mounted VHF/UHF mobile antenna. LOL!

73 Dave K4EET

 

[KE0GXN]

K4EET, I don't know if you get on YouTube much, but here are some videos I found back when I was researching D-130 antenna. I plan on getting one myself once I find the installation expertise with my newly gained HAM knowledge.

https://www.youtube.com/watch?v=B80eDdEEb5M

https://www.youtube.com/watch?v=3ZoKmrsP7i4

He has a couple of others on his channel, but these were the two that most interested me.

I personally think it is a good wideband scanner antenna option. I wouldn't even consider it in for a TX option, but for a RX only option, it seems good.

As you know the N connector version would probably be best, model "D-130NJ."

 

[mmckenna]

Good points all around. Ideally, I would do what you say. I am somewhat limited in "space" based on the fact that I am in a wheelchair and physically a semi-quadriplegic and do not want to over-burden my friends with a real antenna farm. Most signals are fairly strong on my indoor mag-mount antenna for VHF/UHF so an outside discone, even if unity gain or somewhat less since the elements are not quite vertically polarized, should do better than my indoor antenna since it will be outside the aluminum siding and trice as high AGL (above ground level). I do wish I could "do it right" but I think it would be too much for my friends...

One question though, if I did have 3 or 4 dedicated antennas to specific bands with gain for each antenna, how would you combine them into one feed for the scanner? A combiner would be quite expensive.

73, Dave K4EET

OK, so if one antenna is all you want to do, then this is probably the right one. Getting it outside and in the clear, up above surrounding structures is going to help. Since they have essentially zero gain, make the most of it by getting the highest quality coaxial cable you can. The length of the cable would dictate what is "best", but I wouldn't use anything less than LMR-400. LMR-600 or 1/2" heliax (LDF4-50A) would be even better. Basically you'd want to minimize any feed line losses so you don't reduce your overall system gain/loss any more than necessary. This is a place where investing in really good coax might be well worth it. If it's installed correctly and properly weather sealed, no reason why it wouldn't last for a decade or more.

I would ask your helpers, though, what they are willing to do? They might be willing to help you string up a couple of antennas. Doesn't hurt to ask. If I was local, I'd be willing to help. Long story, but a few years back I was confined to a wheel chair for a while, 100% paralyzed head to toe. I'm mostly recovered now, but I haven't forgotten what it was like to be in that position.

You can combine the antennas using a diplexer. You can find them at amateur radio shops. A simple antenna switch is an option, too, but probably would cramp your listening style.

A VHF Ringo antenna would probably work very well on VHF-Low and VHF-High bands. If you've got one, I'd put it up.

 

[K4EET]

Thanks again for everyone's comments. They have been most helpful.

73, Dave K4EET