DX Engineering ARV2 Active Whip - Report

[mstephens741]

I received this ARAV3-1P antenna yesterday. Here's a few quick comments about this antenna. It arrived UPS very well packed. The whip is a one piece tapered 108" rod which they pack in a stout cardboard tube.

When I bought this, I thought $259 was a bit on the high priced side. When I received it, I was amazed that it could be done for this price. It is a marvel of good and proper engineering and manufacturing. I've gotten so used to cheap imported goods with crappy hardware and ludicrous instructions that I had forgotten what a well engineered product felt like. All the pieces are made with beautiful precision and quality materials. High grade aluminum enclosures, and all stainless steel hardware. Remarkable. There is also an 8 x 10 instruction booklet that is both comprehensive and clearly written in REAL ENGLISH!

I assembled the pieces easily in about 15 minutes. I had to add coax, connectors (more about that later) and a 5' copper pipe to complete the installation. Fortunately the copper pipe pounded into the sandy soil easily for about 2 feet. One small quibble with design. The book says "use 3/4" copper pipe." When I got to Lowes, I see 3/4" copper pipe comes in Type M and Type L. One is clearly thicker walled than the other. I choose the thicker walled one because I will be pounding it into the ground. But, the U-bolts were too narrow for the thick walled 3/4" pipe. They were designed for the thin wall. So, with the pole already pounded into the ground, I used a large C-clamp to squeeze 3 spots down so the U-bolts would fit.

The whip and active electronics box mount to a very thick plastic plate which is then U-bolted to the copper pipe. A single coax then leads from this to your indoor station. Indoors is the wall wart power supply, and a small feed box where the antenna and DC power supply connects, and you then connect the radio to this box with a separate coax. This caused some puzzlement to this newbie. The antenna to feed box coax has F-connectors both ends. BUT the feed box then uses an RCA connector as output to the radio. I don't understand the reasoning on that. Finding a RG-6 coax RCA connector was not possible in my Lowes or Radio Shack. I settled for a BNC to RCA adapter and put a BNC on the coax.

My radio has an SMA connector, so the interconnect is hokey. It begins with SMA into an SMA-BNC adapter, The cable is BNC-BNC and connects to an BNC/RCA adapter at the feed box. I wonder why the feed box had an RCA output?

I finally got the thing connected to my WinRadio Excalibur. I really don't know whether to be elated or sad. The antenna raised the overall sig level by about 20+dB (into the range of like -80dB). Such that, listenable signals were hitting S9 to S9+3dB or so. There was still a lot of noise. and I can't say I was impressed by the signal strength. But, this is coming from a newbie who is not sure what the gold standard would be. I know my location is noisy, and my ability to place the antenna in a noise-free area is limited by being on a small mobile plot. So, I know the compromises. I don't know what kind of expectation to have here.

I spent a lot of time playing with the software noise controls, BW and features to make the signal sound better. I shut it down at midnight and wondered like Peggy Lee, "Is that all there is?"

I have a sense that maybe I have missed the "golden age of SWL."

I should emphasize that the DX Engineering antenna was absolutely beautifully made. I would not hesitate for a second to buy other products from them. (No connection of any kind to the company!). If only more things could be made that way.

I have an active loop antenna on order also. It won't be here for a couple weeks though,

 

[SCPD]

I shut it down at midnight and wondered like Peggy Lee, "Is that all there is?"

Well, since we don't know your location, it's a little hard to guess.

Everything from frequency, time of day, location, ionospheric conditions -- can all determine what you're going to be listening to. I have a feeling the loop will make an improved experience.

Also you never really mentioned what you were trying to listen to...

This is why you need to jump on the IRCs and chat. You'll know what is going on at a given time and on what frequencies. Someone will probably be near your location and can at least give you a reference point.

PS. There's always something on... whether or not you can translate the language is another story.

 

[mstephens741]

Yeah, I was being a little facetious. I have only been at this a couple days. I wasn't sure what to expect. I think I am getting a better idea as I get some air time.

I live in the Coachella Valley of California (near Palm Springs). My interest would be news, politics, pirates and propaganda from all parts of the globe. I also enjoy world music. Right now I have the handicap of only speaking English, but I'd like to learn Spanish/Portugese to get more out of Latin America and SA.

I suppose my temporary disappointment was that the spectrum wasn't filthy with signals. I stored perhaps 12 listenable sigs last night. I guess my expectation was like 100? I dunno. I am patient though in the long run, and I will dig and dig.

On the IRC, I will try some more. I haven't given it too much time yet, as I didn't really have my rig running.

 

[SCPD]

Well Token will be a very good reference point for you. He's just north of you.

Yeah you just need to spend more time. A good time for testing your setup is during a HAM contest. Certain bands will light up like a x-mas tree. There's contests just about every weekend.

Feel free to jump on the IRC when you're listening. Then we can compare signals, etc.

We usually get a good group between 6-9pm PDT... more people will be active as conditions warrant.

 

[chrissim]

When I installed mine, I drove two 8 foot ground rods. One mounts the antenna, the other is a few feet away and linked by a ground wire which I trenched and ran through conduit. I also purchased a common mode choke from them when I ordered the antenna, but found I didn't need it. Optimally, there's a certain distance from one ground rod to the other, though I can't remember what it's supposed to be.

The instructions mention the possibility of using two ground rods. You may want to consider linking the two in series. I might add, I have read numerous articles that claim sandy soil isn't the greatest medium to ground with.

As for the F connections that they use, Pixel does the same. I have both my DX Eng vert and my Pixel about 75 or maybe 100 feet away from the house running RG6 quad. I feel I get fantastic reception. I converted mine to RCA to make pulling the antennas during storms ultra easy. I've read some of the guys here use LMR 200 or 400. I haven't experienced a side by side demonstration between the two cable types, but I feel that Pixel wouldn't cheap out on the cable for such an expensive antenna if it wasn't up to snuff.

I recall that I posted a response to one of your posts and suggested this antenna. I live in a rural area, but within a neighborhood. I prefer this antenna over the Pixel loop, or any other antenna that I have up - in my location.

 

[ka3jjz]

Many folks think that a stronger signal is a better way to go. Problem is, too much gain and you get lots of noise along with the signal. Try to go for a signal that is readable, not necessarily 30 over S9. All you're doing is punching too much signal into the WinRadio

If you have a way to adjust the gain on that unit, that's where I would start...Mike

 

[mstephens741]

When I installed mine, I drove two 8 foot ground rods. One mounts the antenna, the other is a few feet away and linked by a ground wire which I trenched and ran through conduit. I also purchased a common mode choke from them when I ordered the antenna, but found I didn't need it. Optimally, there's a certain distance from one ground rod to the other, though I can't remember what it's supposed to be.

The instructions mention the possibility of using two ground rods. You may want to consider linking the two in series. I might add, I have read numerous articles that claim sandy soil isn't the greatest medium to ground with.

As for the F connections that they use, Pixel does the same. I have both my DX Eng vert and my Pixel about 75 or maybe 100 feet away from the house running RG6 quad. I feel I get fantastic reception. I converted mine to RCA to make pulling the antennas during storms ultra easy. I've read some of the guys here use LMR 200 or 400. I haven't experienced a side by side demonstration between the two cable types, but I feel that Pixel wouldn't cheap out on the cable for such an expensive antenna if it wasn't up to snuff.

I recall that I posted a response to one of your posts and suggested this antenna. I live in a rural area, but within a neighborhood. I prefer this antenna over the Pixel loop, or any other antenna that I have up - in my location.

Yes, I got it on your recommendation - thanks. It is beautifully made for sure. My installation is not as robust as yours. I think I will work on that. Yes, I read the two-ground method. Something for me to consider. Maybe especially with the sandy soil here. I have to say though that the idea of two grounds connected by a resistance (wire) sounds a tad odd to me. On electronic gear, I normally prefer a star ground with earth at the center. Not that I have any business questioning the DX engineering guys! Copper pipe is cheap enough to try it.

I think my location is probably questionable too. After looking over the alternative I selected a spot half way along the front to back axis of my house about 3 feet from the house. Probably too close.
Thanks for all the help folks!

 

[chrissim]

Multiple ground rods connected in series is standard practice among hams. Likely more so for lightning protection than anything else.

As I mentioned earlier, sand has a measure of soil resistance, so people in your predicament often bury counterpoises or use some type of copper or metal mat at the ground rod location to circumvent the problem, or so I've read.

Bottom line, if you feel you won't be happy with the vertical, return it immediately. According to Pixel, no ground system is necessary for their loop because it's a closed system. You might be happier with the loop in your circumstances.

Best of luck.

 

[mstephens741]

UPDATE July 19, 2013

I got a very pleasant note from the DX engineering folks today. WOW - what customer service. I should correct a few things from my early review.

1. Their instructions DID say "3/4" OD copper pipe" for the U-bolt. I assumed it meant "nominal 3/4" copper pipe." But they meant "3/4" OD by measurement." So even though the pipe I obtained was nominally a 3/4" copper pipe, the OD was about 0.875". That's a mis-read by me. They are going to add a few words to the manual though, so that idiots like me don't assume!

2. RCA. I asked, "Why an RCA connector on the feed box?" And it turns out that again, my lack of knowledge is at fault. 95% of the radios use an RCA for the external antenna! So, that's what they put on the box. Well now - that makes sense!

The antenna is working quite well. Now, I am not picking up these little feint stations people talk about on IRC, but I am getting a lot of stations even in my noisy compromised area. Considering that my long wire attempt yielded almost NOTHING, this is a huge improvement.

 

[Token]

2. RCA. I asked, "Why an RCA connector on the feed box?" And it turns out that again, my lack of knowledge is at fault. 95% of the radios use an RCA for the external antenna! So, that's what they put on the box. Well now - that makes sense!

95% based on what? This was an answer from the DX Engineering folks? I would be interested in seeing where they got that number. While not hard data, in many decades in the hobby RCA connectors have always seemed, to me, to be in the minority, although years ago they were more common than today.

BNC and UHF seem to be the dominant 75 and 50 Ohm antenna connectors used for SW gear other than portables today in my experience. For higher impedance antenna connections several different connections are used, from spring loaded clips to screw terminals. Portables use a mish-mash of connector styles, including some never meant for antenna stuff.

T!

 

[Arkmood]

I BUT the feed box then uses an RCA connector as output to the radio. I don't understand the reasoning on that.

It makes perfect sense from a manufacturer's viewpoint - RCA connectors are cheaper. And no, the 95% figure can't be justified (opinion), perhaps if using portables as a database but even that's a big if...

In spite of that, and in their favor, high quality/low loss cable/connectors are not as much of a concern in HF vs VHF/UHF...

 

[mstephens741]

Although SWL and scanning is new to me, I am not unfamiliar with product design and engineering. I can say with some experience that "low cost" was not a concern when DX Engineering put an RCA connector on the feed box. Their product is executed at the highest standard of precision and quality of materials. Right down to bagging all the hardware into individual "assemblies" for each step. Not to mention it is all stainless hardware. Scrimping on one connector would not be part of this design, IMO. Anyone examining the product with some engineering experience will be impressed.

In their email to me, they said the RCA was used because most radios historically use RCA connectors. I had no idea that ANY radio used them, so that was why I initially asked about them in my comments here. In the main, I am now versed in the idea that RCA is "not unusual" to be used in this application.

 

[chrissim]

I know you did this, but I am not sure if the instructions emphasize this enough: make sure you seal the box that's grounded to the ground rod. I think they call it the "matching unit," or something similar. I agree that DX Engineering makes robust and fantastic products. The quality is apparent, but these things aren't weather resistant unless you take measures to make them so.

I used coax seal on all the connections. Lowes sells some type of putty that electricians use. It comes in a white plastic packaging and it's less than 3 bucks. I used that to seal the entire box by placing a bead of it any place that moisture could potentially contaminate the matching unit. I also placed it where the matching unit connects to the ground rod via that black wire.

By the way, I read someplace that a user of this antenna bought a larger element and it has helped him receive even weaker signals. I would imagine, being a vertical, a larger element might also bring in more noise, which was likely a design consideration and is why the element is in the neighborhood of 102 inches and not larger.

I also used an MFJ 915 line isolator (adapters needed). It sits about 3 feet below my receiver and works well. The thing comes in through an MFJ patch panel at the window.

 

[Arkmood]

I can say with some experience that "low cost" was not a concern when DX Engineering put an RCA connector on the feed box. Their product is executed at the highest standard of precision and quality of materials

In my view, the use of antiquated RCA connectors in antenna/radio applications (including HF) are not what I consider to be quality of materials.

 

[Token]

Although SWL and scanning is new to me, I am not unfamiliar with product design and engineering. I can say with some experience that "low cost" was not a concern when DX Engineering put an RCA connector on the feed box. Their product is executed at the highest standard of precision and quality of materials. Right down to bagging all the hardware into individual "assemblies" for each step. Not to mention it is all stainless hardware. Scrimping on one connector would not be part of this design, IMO. Anyone examining the product with some engineering experience will be impressed.

In their email to me, they said the RCA was used because most radios historically use RCA connectors. I had no idea that ANY radio used them, so that was why I initially asked about them in my comments here. In the main, I am now versed in the idea that RCA is "not unusual" to be used in this application.

RCA connectors for radio frequency use in the medium wave and above regions are not usual today. It is uncommon, but not unheard of, a small minority of hardware is so equipped and most hardware that is so equipped is indeed of lesser quality or cost. You use RCA connectors for RF when you are not horribly concerned with maintaining impedance, shielding, and / or you are not all that worried about minor losses. They were, as near as I can figure, never in majority use, even for receive only applications. In the 50’s to 70’s time frame they were more common than today, particularly on lower end gear.

RCA connectors rely totally on friction to maintain both mechanical connection and electrical conductivity, this is never desirable even when it is acceptable. If the metal of either the female center conductor on the jack, or the male outer conductor on the plug become fatigued both conductivity and mechanical retention are lost.

RCA jacks are indeed lower cost than almost any other type of connector that might be used for this application. As far as I know low cost is the only advantage of this connector over any normal RF connector. Finding coax pre-made with RCA connectors on one end (or both ends) is difficult in comparison to any “normal” RF connector. Finding a quality RCA to any “normal” RF connector adapter is more difficult than say BNC to UHF or F type.

RCA connectors were originally designed (in the 40’s) for audio, with a design top frequency of about 1 MHz. As the connector matured it came into use for video applications, it was deemed acceptable for use up to about 10 or 15 MHz. If losses are not a driving factor this connector can be used up to about 100 MHz. The RCA connector is not normally considered an RF connector, but rather an audio and video connector.

If any of my technicians or engineers suggested using an RCA connector on any RF application I would recommend that he / she reconsider. The few percent of cost savings is not worth the increased failure rate and less predictable performance when compared to say BNC. Unless they had a well defined reason to specify RCA (none that I can think of off the top of my head) then it ain’t happening on any project any of my people are involved in.

T!

 

[chrissim]

I should clarify for all. There are no RCA connectors on the DX Engineering ARAV. They use F connections on their matching unit (as does Pixel and likely Wellbrook). I believe the original intent for the OP was using them as adapters, because they simply do not exist on the ARAV unit or anywhere along the chain unless the user supplies them, which is completely optional.

Personally, I use RCA adapters on my Pixel and the ARAV in the house for quick disconnection during a storm. Never had an issue. I always make comparisons before I make a switch such as this. I'm sure there's some gadget somewhere that will reveal that I'm losing something in the process, but my ears sure can't tell. Adapter or no adapter - sounds the same to me. Weak signal reception doesn't change. The Excalibur reports the same signals across the board rather or not I use RCA adapters. Perhaps I'm missing something. I would be interested in hearing thoughts about RCA adapters, as the main focus seems to be a direct RCA on a receiver itself, rather than using them as adapters. Though I would have to imagine that if impedance matching is a concern when they are present as an antenna input on a radio, then using RCA adapters would be a concern as well

I'll also mention that there was quite a discussion on another board concerning the use of RCA adapters. After reading those comments, I decided to use them as I prefer to pull rather than unscrew when weather gets ugly.

 

[mstephens741]

Clarification

In my ARAV3 kit, there are two metal boxes. One goes on the antenna post, and one goes in the house - I believe it is referred to as a "shack". The names of these boxes I will not concern myself with so as not to add new confusion over nomenclature.

Of the first box - it has an F connector for the coax which will go into the shack and connect to the second box.

Of the second box, it has three connections as follows:
1. A DC socket for the wall wart power supply.
2. An F connector which receives the coax from the outside box previously mentioned.
3. An RCA female connector for the coax that goes to the receiver.

I used an RCA:BNC adapter on one end, and an SMA:BNC adapter on the other end of the coax mentioned in #3.

I am not an RF engineer, so I will not offer that kind of opinion. But I have designed dozens of electronic devices in the field of audio, and I have also manufactured them for profit, and owned those businesses. So, I feel competent to offer an opinion about cost strategies in general. Yes, the RCA connector would cost some cents less than another connector. But no, that cost saving probably is not the reason it was used. You wouldn't use 150 high quality parts, and then toss in one cheap one to save a few cents as a cost strategy. That would make no sense to anyone in business. I suspect they could use any connector in that spot they wanted without undue concern over their profit margins. IMO, it was used because they considered it to be the one which would offer the most convenience to their users. I didn't know that, because I have never owned a SW receiver before.

I can only back that up with their message to me, which says in effect that for "receive only" radios, they considered the RCA to be the most common. Now, if that's incorrect - so be it. But I don't see it as useful cost reduction when there are dozens of other opportunities to lower the cost far more substantially without attracting the least bit of attention.

 

[mstephens741]

I know you did this, but I am not sure if the instructions emphasize this enough: make sure you seal the box that's grounded to the ground rod.

Haven't yet, but I sure intend to waterproof the whole thing. Thanks for the reminder!

 

[Arkmood]

Clarification

Sounds like they've degraded (new version) their product for a reason they can't properly justify - at the price of a profit margin, which doesn't really exist.

 

[chrissim]

I need to correct myself. There is indeed one RCA input, it's on the "junction" box that resides in doors. An SO-239 would not fit properly in that box, which is why they opted for an RCA input. I am not sure why they didn't continue the pattern of F connections, though.

Design considerations such as these are fine. You can see manufacturers, such as Winradio, omitting standard connections in favor of SMA-BNC when real estate is at a premium.

I'm looking forward to your review of the Pixel when it finally arrives in comparison to the ARAV. My ARAV consistently outperforms my Pixel and would like to hear of your experiences of the two.