the article starts at http://www.spectrum.ieee.org/feb09/7328

The gain figure listed for C4 on the Antennas Direct website has been changed to 12.2 dBi. This value is reasonable in comparison to C1 and C2 and is consistent with the gain curves computed by X-FDTD (a very good, but not perfect simulator). We are working on the other stuff, but please try to remain patient as our to-do-list is a mile long.

Best Wishes!

John

Greetings,

John, alerted me to this thread. (I ‘m the owner of Antennas Direct)

Holl_ands: you were correct about the gain discrepancy on the C4 web page. Thanks for pointing that out. It is actually about 12 dBi not 14. We have made that change on the page. I looks like there was copying and pasting from an early tradeshow spec sheet.

As for legibility of the plots; We'll work on recreating those to be more legible. I think it was a copy of a copy of a screen shot so it’s probably not the best artwork.

All of our gain claims in regards to antennas performance should be considered dBi; we'll double check the site to make sure this is specified. Again as John noted, its not about trying to show the biggest gain number for marketing, but what is appropriate and accurate for measurement and testing.

We really are not trying to hide any thing, infact we have been touring the US presenting our test data for review by broadcast engineers and at conferences held by the NAB, the Society of Broadcast Engineers and IEEE.

Last September we sent out hundreds of Clearstream samples to DTV station engineers around the US for their evaluation and criticism. (With the assumption, that if you can pass muster with that group then there is likely merit to the designs) The response has been pretty gratifying as we have dozens of stations across the US actually endorsing the Clearstream family on air and a few of the stations are even selling them directly to their viewers. Many stations were impressed enough with the performance that we were invited out to participate in educational events targeted towards frustrated DTV viewers. So we began a road show and so far have given away out about 6000 antennas to people who were having trouble with their DTV reception.
http://www.antennasdirect.com/blog

The C4 (and the rest of the Clearstreams) are not a magic antennas by any means but they do seem to have a better overall batting average than anything we have made to date. (which translates in to fewer returns and refunds!)

I hope this response wasn’t too sales oriented but I wanted to share with this group the effort placed in these new designs. We are also extremely lucky that the engineering team, led by John are among some of the best RF engineers around.

Thanks for the feedback and I hope this was useful.

Richard

I know this is a little off topic but why hasn't Antennas Direct resized their bowtie designs?

It appears that they know they peak way too high for the new USA TV band allocations.

Is the clearstream desing going to replace them?

Resizing the bow-ties is on our to-to-list. For now the clearstreams are going to be sold along side the bow-ties not replace them.

John

The C4 (and the rest of the Clearstreams) are not a magic antennas by any means but they do seem to have a better overall batting average than anything we have made to date. (which translates in to fewer returns and refunds!)


The C2 does look durable. My initial impression of it when I first saw it was that it was made for the RV and Marine market. It does look like it has high wind load for its small size though.

I know this is a little off topic but why hasn't Antennas Direct resized their bowtie designs?

It appears that they know they peak way too high for the new USA TV band allocations.

Is the clearstream desing going to replace them?
I wouldn't be too quick to throw away coverage for Ch52++.

When the so-called "700 MHz" systems finally come on-line,
we may find a couple of "must haves" in the mix,
forcing us to dust off our old full-band antenna....
It only takes one new "killer app"....

I wouldn't be too quick to throw away coverage for Ch52++.Besides Canada's date is way off in 2011.

Yes, but most of those antennas are still tuned for ch 83, even moving the range down to ch 69 would be an improvement.

I want to start getting my father in-law setup OTA and was looking at antennas from some of the suppliers around here. I noticed just now on Durham Radio's website from Whitby

New DB8 Redesigned for 2009 - Now 22% higher net gain!

Is there actually a new design for this year? I have not seen it mentioned anywhere else in the forums. Of course the next question is, is it actually better. At $10 more than the 4228HD this may be my choice for him. He is about 45 miles from the CN Tower and between 66 and 90 miles from the transmitters in Buffalo.

@JC Newfie: I haven't seen the design of the "old" DB8 to compare. However, this DB8 appears to have some of the same attributes as the old CM4228. And judging by the gain, it's likely the best choice going right now in 8 bay UHF antenna.

JER3: Have you looked at using C5 and adding C2 elements in between for a combo. VHF(hi) and UHF. I think it would be a small size (about 25"X25") with common reflector.

xauto: Yes, the design gets complicated but we have several options on the drawing board. That is about all I can say for now.

I am looking to buy a DB8, but noticed slight differances in ads. Three show sides conected to centre transformer with cable. Two show coupler bar. Is one better or newer than the other.

I have the DB8 antenna.
It is basically two DB4's connected together. So, you can flip one of the DB4's in the opposite direction. I haven't set mine up that way. No need to. But, perhaps you can test it that way and see if it works for you.

Not sure we have gear review section...Antenna Direct has a new product 'Clear Stream 4", seems to have extreme range for digital TV. The design looks a little 'space age' compare to regular bowtie antenna.

See the thread that covers the Ajax area to see what OTA gear your neighbours are having success with:

http://www.digitalhome.ca/forum/showthread.php?t=36538

And regarding what you read on Antennas Direct's web page, here's what Ken Nist at HDTVprimer has to say:This company makes mostly good antennas. But their marketing department lives in their own little world in which they are allowed to claim anything without fear of consequences. Their web site is especially untrustworthy.So while the ClearStream 4 has the potential to be a great antenna, you can't judge it by what you read on sales sites.

Antennas Direct's upcoming C-5 VHF-HI antenna is not on yet on the market but is discussed and analyzed in the Antenna Research and Development forum in this thread:

http://www.digitalhome.ca/forum/showthread.php?t=107428

NAB Report re Antennas-Direct Smart Antenna has been "Approved for Public Release":
http://www.nabfastroad.org/NAB_Final_Report_Rev_Public2.pdf

Note that this was an R&D effort....and only covered UHF Band....

So I bought the C4 because I knew my local digital channels (Los Angeles) were going from UHF to High VHF for channel 7, 9, 11, 13. This antenna works great for UHF but I get 0 signal on the High VHF. Here is my TVfool info:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d663d23d52b0c16

So I have the C4 with the channelmaster 7777. I live in an apartment with the balcony facing the towers (north/west). Will the C5 work along my C4 for channel 7, 9, 11 and 13. I guess I am about 57 miles away.

Like I said, I was getting all the UHF (upto UHF 66) before the change.

Thanks.