Portable wideband antenna for camper.

[dlwtrunked]

Get this little discone. Worked good inside my house in the winter until I put up my full size discone in the spring. I take it camping now along with a survey tripod and a 12 foot pvc pole.

Diamond® Antenna ~ D220R

Although I have a tower with other antennas on it, I keep one of these D220 on a desktop mic vertical stand that I can take around to where I want. It works well and easily comes apart. I also keep one unassembled in a camera tripod bag. The only one to evaluate an antenna is to try one--too much is based on "beliefs".

The most expensive antenna I ever bought (about 35 years ago) made by a company still selling it (with no return policy), worked so poorly that I destructively took it apart to try to figure out why. Yet, many reviewers say it is the best antenna they ever tried--leaving me wondering what they had actually tried.

 

[TailGator911]

I'd like to get a wideband antenna to use while camping in our camper, I'd mount it on a temporary mast, wideband because I'll never know what frequencies might be used in whatever area we are in. A discone would be ideal however it would take up too much storage room inside the camper while traveling.

I've never actually seen a discone in person, do they come apart easily so it could be stored?

Other thought was a mobile antenna with a ground plane kit but I haven't seen one as wideband as a discone.

Any other suggestions?

I recommend the Diamond 220R wideband discone. I mount mine on my Winnebago Via and it works wonders. It's smaller than any other discone and the receive is great. Used it on an rv excursion to Alaska last year and was pleasantly surprised.

 

[doctordialtone]

I recommend the Diamond 220R wideband discone.

I agree!

See post #2

 

[iMONITOR]

 

[vagrant]

Could one of you with a D220R post an SWR plot image of it using a VNA or the like? It could be the full frequency span of 100 - 1600 MHz, or broken down in two 100-800 & 800-1600, or even into three 100-500, 500-1000, 1000-1600 would be even better, or as high in frequency as your VNA will go. Set the maximum SWR to 5 or close to that, because when you set it to 25 or 50 most anything will look flat. While you're at it, could you take off that top element and let us know which band(s) that affects.

It would be appreciated, as I am curious about this antenna. My guess is that the top element is what would be handling the lowest freq and it may be rather narrow. The numbers will tell us more, but this antenna seems like it would only handle a chunk of just UHF. There's nothing wrong with that, but honestly 100 to 1600 MHz? If the result is crazy flat, I would then request one use a multimeter and check the resistance.

I am not arguing anyone's claim on what that antenna does for them, or looking to be a troll. RF is funny as we all know. I would just enjoy some clarity via a plot or several and some info on how and where the antenna was mounted when performing the sweep. Please and thank you.

 

[Ubbe]

The discones dimensions seems to correspond with it's name, that the lowest discone frequency are 220MHz. But for some reason the top element are a 144Mhz 1/2 wave and a 2x5/8 at 440Mhz so it will turn into a GP antenna at 144MHz and 440MHz and whatever other frequencies it works at and ruin the discones function. So basicly it only works as an expensive ground plane antenna tuned to 144MHz and 440MHz and at higher frequencies it begins to operate as a discone, if the top element doesn't interact too much.

/Ubbe

 

[prcguy]

Looks like the Discone part comes into play more like 370MHz range on up with the whip doing what was mentioned. What is the length of the skirt radials of the Discone? That length will be close to a 1/4 wavelength of the lowest cutoff frequency for the Discone. Are those radials solid metal or wire coils over an insulated rod covered with heatshrink, etc?

The discones dimensions seems to correspond with it's name, that the lowest discone frequency are 220MHz. But for some reason the top element are a 144Mhz 1/2 wave and a 2x5/8 at 440Mhz so it will turn into a GP antenna at 144MHz and 440MHz and whatever other frequencies it works at and ruin the discones function. So basicly it only works as an expensive ground plane antenna tuned to 144MHz and 440MHz and at higher frequencies it begins to operate as a discone, if the top element doesn't interact too much.

/Ubbe

 

[iMONITOR]

Looks like the Discone part comes into play more like 370MHz range on up with the whip doing what was mentioned. What is the length of the skirt radials of the Discone? That length will be close to a 1/4 wavelength of the lowest cutoff frequency for the Discone. Are those radials solid metal or wire coils over an insulated rod covered with heatshrink, etc?

I no longer have my D220R so I can't measure the radials so I'm only guessing when I say about 8 inches. The radials are not solid. They do have wire coils over and insulated rod covered with heatshrink. Also they're not all the same. Three of them are slightly thicker in diameter than the other three.

 

[iMONITOR]

This shows the three thicker radials. The wire that is wound around all 6 elements is of a small gage effective making it quite long.

 

[Ubbe]

It's the horisontal elements that are the important lenghts as those receive the signal. The lower skirt, cone elements, could have some sort of coil arrangements but that are not used as a discone and are working as shortened GP elements for the 144MHz top whip.

You can see from the SWR that it is good for the top whip tuned frequencies and are terrible elsewhere except 500Mhz and up. Should be a good working 700-900Mhz discone and with an assisted top whip for the amateur bands. At least there are enough metal to make it work better than a telescope antenna.

/Ubbe

 

[prcguy]

Hmm, probably tuned radials for the top whip. Also probably a lousy Discone not meeting the basic design criteria except for the top hat and three non loaded radials. And a PL-259 for frequencies above 500MHz?

Edit: All radials are loaded? Is this thing designed by Dr. Frankenstein?

This shows the three thicker radials. The wire that is wound around all 6 elements is of a small gage effective making it quite long.


View attachment 88469

 

[dlwtrunked]

Could one of you with a D220R post an SWR plot image of it using a VNA or the like? It could be the full frequency span of 100 - 1600 MHz, or broken down in two 100-800 & 800-1600, or even into three 100-500, 500-1000, 1000-1600 would be even better, or as high in frequency as your VNA will go. Set the maximum SWR to 5 or close to that, because when you set it to 25 or 50 most anything will look flat. While you're at it, could you take off that top element and let us know which band(s) that affects.
...here the antenna was mounted when performing the sweep. Please and thank you.

Google does swr matter for a receive antenna
and the first thing that will come up will say at the very beginning "There is no relationship between SWR and receive performance. " The bold is theirs. Although someone else did post plots, I did measure mine years ago. Unfortunately, I did not keep high resolution versions of the image. The red is the SWR.

 

[dlwtrunked]

I meant to also add, the only way to really measure receive performance of an antenna is to put it into actual use in the field or in a test chamber. A primary reason is that gain varies in directions and that cannot be measured by just connecting an VNA to the antenna.

 

[iMONITOR]

Edit: All radials are loaded? Is this thing designed by Dr. Frankenstein?

 

[Arkmood]

Is this thing designed by Dr. Frankenstein?

Not the Monster, but The Bride note the hair (hot mess) - typical of an atypical designed Discone...

 

[vagrant]

This is fantastic feedback. Thank you all. The video and the plots are interesting and help me to understand if my “speculation“ was close or way off. Without one in hand, I did not know about the wire around those elements either. This feedback is informative.

Additionally, as prcguy pointed out, it is weird they did not use an N connector with the UHF bit it covers in mind, but I am not privy to whats what in Diamond’s antenna world. Maybe the Frankenstein mfg. facility told them they can have all the N connectors they want, as long as they’re PL-259.

 

[iMONITOR]

This is fantastic feedback. Thank you all. The video and the plots are interesting and help me to understand if my “speculation“ was close or way off. Without one in hand, I did not know about the wire around those elements either. This feedback is informative.

Additionally, as prcguy pointed out, it is weird they did not use an N connector with the UHF bit it covers in mind, but I am not privy to whats what in Diamond’s antenna world. Maybe the Frankenstein mfg. facility told them they can have all the N connectors they want, as long as they’re PL-259.

Diamond originally designed this antenna specifically as a dual-band mag-mounted mobile antenna for 2M/70cm amateur ham radio (hence the PL259 choice) Every review I've read from people using it for that purpose give it excellent reviews. I don't worry about it, it works just fine even on the 800MHz band. Mine main use was for VHF/UHF aircraft but I did find the DPD Production Mil-Tenna OMNI performed better.

At least one RR member is using one on his house, I apologize I don't remember who it was, but here is the picture he posted of the installation, I don't think he'll mind if I post it here. Maybe he'll chime in and tell us how it's been working.


There was an earlier design where the top whip was a little longer and had two coils. It was the D220 (discontinued, but currently there is one on Ebay), where as the D220R is the newer version. Then there is a very similar clone on Ebay that is a little cheaper.

 

[Ubbe]

and the first thing that will come up will say at the very beginning "There is no relationship between SWR and receive performance. "

Remember that a dummy load have a perfect SWR but doesn't work at all as an antenna. I modified my Diamond X510 and removed all SWR compensating circuits and got 3:1 as best and usually 5:1 but signal strenght increased 3 times on most frequencies and works great on low-vhf, airband and 420Mhz where it is not tuned to. So you can not be sure of that a low SWR equals a good antenna, but usually it's an indication of where in the frequency bands it will work best.

/Ubbe

 

[JSTARS03]

The LP-3512/VRC looks nice and eXtra dorky with the capacity hat at half the height. My head has enough holes in it, so my SUV would have to handle one of those if/when I find one.

P.S. - There is a NIB HP-3512/VRC on eBay for around $240 shipped out of Spain.

Very tempting. Wender how ordering one from Spain would be. The seller has good feedback

 

[vagrant]

I recommend you find out if there are additional duties and taxes on importing that. Setting one’s expectations ahead of time is good. Still, if that was the low profile capacity hat version I would be tempted. Hmm...then again the larger whip does breakdown for transport.

Yes, you should get that one from Spain so I have less competition if one shows up domestically.