Freevision FV-HD30 Antenna

Piggie

Super Moderator
#21
The UHF "gain" curve is noting to write home about, either.

+0.6 dBi on 14
+3.9 dBi on 22
+4.1 dBi on 30
+7.0 dBi on 38
+1.7 dBi on 46
-1.1 dBi on 51

VSWR on high VHF ranges from 1.7 to 2.7. UHF stays between 1.3 to 1.9 across the UHF band.

Perhaps you should ask them for the spec sheet since WG isn't proud enough of it to actually post it on their own web site.
I am not here to disagree with this at all and love your input. But your presentation is harsh. It's all in the wording, not the technical information. Any reader would just say forget this antenna without looking at the market for which it was designed. It also affects other posters wondering if they should post then get such a reply.

It's not a XG-91 or an old style 4228. It wasn't meant to compete with these antennas. It's a suburban antenna, or even urban designed for a strong signal environment but building construction my be preventing reception.

The antenna on UHF is a single bowtie in front of a reflector. It does drop badly at the band edges I agree is this information is correct, but I am not here to doubt if it is correct. It is more centered in the band than a lot of antenna on the market that were designed for the old band.

Standing waves are very important on transmitter. The reflected power in particular at higher power levels will ruin a final stage.

But if you take the equation for standing wave.

Pu = {1 – [(S-1)/(S+1)]^2 }Pt
Where Pu is the power to the receiving device, where Pt is total power available.

So if you have a 2.7:1 ratio you have 79 percent of the power available compared if you had a perfect match.

If you take the power equation for db = 10 log (P1/P2)

79% turns out to be a loss of 1 db of power to the receiver.

Every db counts but one db is not a deal breaker in most situations unless you are dead on the digital cliff. Most people have trouble seeing a 3db increase unless they are really near the cliff.

There are other companies I can't find all their specs either, so it does seem a growing and disturbing trend.
 

Piggie

Super Moderator
#23
Piggie,

I received the spec sheet from Hans today. It matches what Project posted.
Specs are attached.

Rick
Now take the HD-1080 on paper. Dang it I can't attach a PDF that big!!
But having saved the URL, http://www.winegard.com/kbase/upload/HD-1080.pdf

Note there just isn't much difference on VHF, with the specs on the HD-1080 looking better on VHF, where I was told by Winegard would be better on the FV compared to the 1080. ???? Well short of something happening or a weather change (frequent lately) I am comparing them tomorrow. I think now I need to do a test without the HDP-269, though as far in the woods as I live it should not make a difference.

One thing I can say is right away I didn't see the patterns on UHF, then again I am looking at a quality meter. I may be getting fooled (probably am) by the quality meter staying high as I turn the antenna. But I can say I can see a much narrower forward lobe on the U-75R with the same quality meter and it's up at 23 ft.

Good VHF reception to me seems more a matter of just being close enough to the transmitter that dang near anything isn't blasted by noise or co-channel from the next town (so crowded at least in FL). I doubt if I doubled my YA-1713s to a quad stack it would make enough difference to justify the work. I did ask Winegard and probably should stay on it, if I could buy 2 front sections for each antenna about doubling their boom length. The element spacing vs where the boom goes together one could just remove a plastic plug, drill a hole, push in another front section and add another 3 directors to the yagi. Since all the forward directors have the same spacing, this should work. One would then have to move the boom to mast clamp (2 more holes drilled) but it would be a lot less bulking than building a quad array.

Opps I got off topic again! lol.
I think I need to buy one of those little antenna meters to really continue this test. Too bad I don't have something for VHF, but then again, I don't have a decent VHF signal to compare anything but deep fringe antennas.
 

Piggie

Super Moderator
#24
Will be nice to have a direct comparison. :) How's the build quality?
Only the FreeVision antenna was sampled to me by Winegard. I bought the HDP-269 preamp and the HD-1080 from Solidsignal.com to complete the comparison study.

Comparison tomorrow is planned. The black is plastic. I am not a material science engineer, so I don't know how it will hold up. The antenna is light as feather, at about 1.12 lbs per Winegard. So you can hang it from a thumbtack.

I felt over all considering the plastic it was well built. However the HD-1080 is all traditional antenna aluminum.

The FV is 2/3 the size of the HD-1080 and would take up a lot less wall of closet space.

The one thing I didn't like about the FV assembly that was extremely easy was attaching the UHF driven elements. Even tightening them down, because the are held with 2 points (screws) the can rotate about 5 degrees either way without much pressure. If you do the calculations for 5 degrees off plane, it's very slight. Again this being an antenna for a strong RF field, it's not a DX wonder, never was never will, wasn't ever intended to be compared to antennas with a lot of gain or even moderate gain.
 
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Piggie

Super Moderator
#25
If an extra $10-$25 spent on an antenna meant the difference of receiving 2-4 more channels over rabbit ears, it might be worth the investment.
The HD-1080 runs about $40 shipped. I know several people from the Orlando OTA thread on AVS that said they were using them in Cocoa and Melbourne about 25 to 40 miles from the Bithlo towers. Now the Bithlo towers are all 500 meter towers. Some have them in attics even without an amp and short coax to a single TV. Another person when from not getting WESH on RF 11 in the north part of Orlando 22 miles from the towers. He could almost get WESH (hi VHF) on rabbit ears. He found a hot spot with the rabbit ears on a long coax and was not reliable, too close to the cliff. He bought a HD-1080, put it in the same place and gained about 10 points on his quality meter, enough to stay above the cliff. He said the UHF stations pegged his meter and WESH was about 70 where the cliff is about 58 or so on his meter. So yes, he was happy. He could not put up an outside antenna.
 

IDRick

DTVUSA Member
#26
My son's FV is supposed to arrive on Friday. I'll be able to give it a quick test here and then test it in Boise over Christmas break. My only high vhf has a NM of 56 dB (30 miles, LOS). We have a great signal on this station. I can get a 10 dB margin to dropout with just a balun connected to coax! I'm sure the FV will beat that... :) My 4 bay mclapp consistently has a 48 dB margin with this station. Actual received signal is about 10 dB higher (need to add back receiver NF, balun, and cable losses). Based on my previous testing, I would expect about a 35 dB margin with the FV.

In Boise, my son has three high vhf (ch 7, 10, and 13) at 10 miles, LOS. One can estimate expected signal by adding antenna gain to the NM. In my son's case, the expected signals would be:

ch 7 63.9 dB - 10.3 = 53.9 dB
ch 10 56.3 - 8.8 = 47.5 dB
ch 13 58.3 - 7.5 = 50.8 dB

Even though the FV has a negative gain on vhf, he still should have plenty of signal available to power two tvs. His apartment is up on the 4th floor and has a good angle to the towers. It will interesting to check it out... :)

Thanks for reporting your early test results Piggie! Look forward to reading your results from tomorrow's testing.

Best,

Rick
 
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Piggie

Super Moderator
#27
Again, Winegard sampled the Freevision antenna for my tests. But I bought the HDP-269 Preamp and the HD-1080 antenna.

Today's Test with the FV antenna. I took it down and put up the HD-1080 in it's place. I ran into a very strange thing so before I write about the HD-1080 compared let's talk more about the FV.

My neighbor bought a Sylvania SRT902A 9 inch wide screen LCD portable for $100 from Walmart. Walmart.com: Sylvania 9" Portable LCD TV, SRT902A: TVs

It came with a 30 inch whip (didn't measure, guessed). I set the antenna to 5 inches.
The receiver was on a table about 3 ft high on the porch that faced toward Gainesville. The porch is attached to a small trailer with aluminum skin. We were obviously outside it's shielding but it probably reflected some of the signal. TV Fool

The only station that would lock was WUFT RabbitEars.Info and it was borderline. We had to play with the antenna for several minutes to get a lock. Then it would break up a little off and on.

The whip antenna on the set is conveniently attached to the set with an f-fitting. It comes with a short piece of coax if you want to move the antenna about 3 ft from the set. This didn't help above, actually made it worse.

So we removed the whip antenna and attached the FreeVision with the coax that comes with the FreeVision that is tiny but with a male f-fitting on each end and about 5 ft long. There was no amp.

With the FreeVision attached no only did WUFT become solid but we also picked up the rest of the Gainesville UHF towers RabbitEars.Info giving a reliable signal.

This was a huge difference, only 3 ft off the ground with the farthest station 37 miles away on a 300 m tower running about 150 KW ERP in our direction with a 1 edge refraction and 24.7 db NM.

Conclusion from this test is the FreeVision works very well all by itself as an auxiliary antenna to portable sets. The antenna is small enough to carry along with such a portable. Again it's not a XG-91, but it allowed us to watch all the Gainesville UHF. Personally I was very impressed.
 
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Piggie

Super Moderator
#29
Piggie,

Nice report! How did you make the nifty report using rabbitears data? Great job!

Best,

Rick
Trip did the coding and I did the alpha testing on that set up. Some of the coding originally was done by someone I can't remember ask Trip. It's been up and running since August and I think it's been under advertised at least on this forum.

Go to RabbitEars.info and set up an account on the home page so you can log in.

Then Click DXTools toward the top of the page. In a nutshell and when I get off work or tommorrow I will write out a how.

1) Set up your account on RabbitEars.info (not RabbiTears.info lol).
2) Go to DXTools and set up your first location. (must be done with coordinates).
3) Then view that location.
4) Once viewing your location (you can make more than one), click add a report. It brings up a help page then takes you to where you add a station.
5) Once you add a station you can either go back to the map location or keep adding stations to that location which is the default.

Two ways to view people's reports. One is they give you the URL

The other is if you go to the station listings RabbitEars.Info , the find a station, click to open it, then click to open technical data and screencaps. Then you will see a link SCM (social coverage maps) and click it and you will see everyone that say put up a report to that station.

I wish I could give a link to show all my reports at once. If there is I don't know about it.

If you want to see my main array plot it's here. RabbitEars.Info

I didn't put in all my DXing, just the stuff I see normally without skip, even if it's barely there.

I need to do a DX map. I think that would be better than cluttering my normal coverage map with DX, even though trip has a way to separate them.

Everyone should do one. It does give away your house location, but I am not that paranoid.
 

Piggie

Super Moderator
#32
Piggie,

Nice report! How did you make the nifty report using rabbitears data? Great job!

Best,

Rick
Something we need to ask Trip. On this page RabbitEars.Info , the Power Level column numbers do not match my calculations for my location which are very close to TVFools calculations.

Trip, you read the entire Internet (A.I) so how do you compute those power levels? I think they are in error. Talk me down or hopefully find why.
 

Piggie

Super Moderator
#33
HD-1080 tests and comparisons to the FreeVision

Well it's been up for 2 days. So now I think I can give my results.

Here is the TVFool Report again for the test location TV Fool

Here is my Social Coverage Map of the test on RabbitEars.info http://www.rabbitears.info/dxlocation.php?id=169

The Winegard specs for the HD-1080 http://www.winegard.com/kbase/upload/HD-1080.pdf

Don't look at the gain numbers so much but look at the polar antenna plots, in particular noting the skew.

The skew was obvious on my test channels, 16, 28, 29 (LP analog), 31, 36 and yes, VHF 11 (WESH). Note if you look up 29 W29AB on TVFool the data is totally wrong. It's not digital yet and it's still on Ch 29 analog TV Query Results -- Video Division (FCC) USA

The HD-1080 compared to the Winegard FreeVision showed much sharper (not compared to a yagi, etc but to the FV) lobes. It also showed a little better front to back, though with only a quality meter it was a very rough test for front to back on UHF.

The UHF pattern was skewed just as the spec sheet shows on both UHF.

I didn't have enough signal to see the shown fact that VHF is actually stronger off the back on VHF except on ch 11 WESH. I was totally shocked. It turned out to be a fluke of the test. First we has excellent VHF propagation between me and Orlando. I pointed the antenna at Gainesville and checked the levels. I did a scan with the Insignia just for consistency and low and behold WESH CH11 locked. I turned the antenna at it and it would not lock but skewed about 7 o'clock off the back (as seen in the specs) if the front of the antenna is referenced as 12 o'clock. There was clearly more gain on Ch 11 off the back. The lock was borderline and is there one moment and then not the next. Still pretty amazing for 83 miles, but again, most of the reason I got to test this was atmospheric conditions. In no way shape or form am I saying this is an 83 mile antenna! I just got lucky to test it on VHF. I had tried WESH that same day before taking down the FreeVision and it would not lock, though I could see something on the meter.

Now also remember I am in a fringe area for UHF and deep fringe for VHF. So I am testing the antenna outside of it's intended environment (as well at the FreeVision).

I suspect though I will need to wait for a windy day in the spring, the HD-1080 would go better on wind driven multipath due to it's sharper forward lobes. This is purely a guess.

Construction: The HD-1080 is built much more like a traditional antenna. Fold out elements. I didn't find the instructions very useful and ended up calling Winegard to be sure I was putting it together correctly. As much as I love their antennas this could confound some people. But the antenna is solid, feels like a traditional antenna. It is truly an outside antenna, about 50% bigger than the Winegard FreeVision. I has two mount points (top and bottom) being traditional boom to mast clamps. I believe it would take a lot of wind to bother this antenna. However I would not suggest putting this antenna high on a pole or tower, as it's bidirectional nature would certainly cause co-channel problems in a crowded VHF environment such as where I live.

The antenna is small enough to be mounted on a satellite j-pole mount if the j-pole is inverted. Another stumbling block for someone not mechanically inclined such as constructing the antenna.

All in all it at least "feels" more rugged than the FreeVision. And probably a better choice for someone that like a solid feel for an outdoor install on a short pole or satellite j-pole mount. It needs a pole to mount to, where the FreeVision can be hung on a wall.

Don't take this as me saying the FreeVision is not built tough enough, it is. The FreeVision has a single boom to mast, though there is room for two if you could find another one meant to be used on that antenna, but it's so light it doesn't need the second mount. The single mount also would let someone remove a dish from an old install (like switching satellite companies and they leave the old on set up).

For the FreeVision one could buy Winegard DS 1111 Antenna Mount for Satellite Dishes (DS-1111) - Winegard - DS-1111 - 615798315085 - SQS DS1111 DS111 DS 1111 piggy back mount an mount a FreeVision this way without fear of putting too much strain on the satellite mount.



Note the image shows a Winegard Wingman attached but the FreeVision could easily be mounted to this adapter.

The FreeVision , one can mount the boom to mast clamp at the top or bottom of the antenna. In the above case, mounting it at the bottom would let the antenna be above the pole and away from any metal poles.

======

Overall Conclusion.

Thought they sell for about the same price, they are meant for 2 different types of installs. The HD-1080 does seem to be stronger on VHF but off it's back which won't help in most cases. However it's not designed nor the FreeVision for anything but a 30 mile antenna where the VHF should be strong enough not to matter it's stronger off the back.

Do you want a camping or emergency antenna? The FreeVision wins hands down. Even if you wanted to carry it in it's shipping box, it's only 2 screws and wing nuts to take it apart and carry it in it's box. Though constructed it could go in a cubby hole in a motor home, then just hung on the side of the motor home.

It only takes 5 minutes tops to take it out of the box and construct the antenna. Though some might consider even this too much, it's much easier to fold up than the HD-1080 (which is meant for a permanent more traditional mount on a home).

So both antenna had their virtues. If I were permanently mounting it to a pole, I think I would choose the HD-1080. For more non traditional mounting the FreeVision wins, though one can mount it traditionally also.

As I stated earlier I don't think either antenna should be up very high. If you need to be more than 10 to 12 feet off the ground, right away either is the wrong antenna, as you are not typically within 30 miles of the towers and you are trying to achieve LOS by going up 20 ft or so, but then you risk more co-channel in particular on VHF.

I think the test with the FreeVision on the Sylvania 9" portable says a lot. There isn't even a quality meter on the TV. But yet it provided a lot more reception than the built in whip. The little 5 feet of mini coax that comes with the FreeVision was more than enough to just hang the antenna near the portable. The same thing could be done on the wall behind a TV in an apartment in town where rabbit ears where not enough even though the gain figures don't seem to lend this to be true, the test with the Sylvania convinced me.

I think over all the FreeVision wins. It works as well as the HD-1080 off the front (trying to judge non-locking VHF stations on the quality meter) and matches UHF to the HD-1080 off the front.

Someone with very little mechanical skills could construct the antenna and the instructions are much more clear than the HD-1080. It will mount more places and again for someone with limited skills.

The box on the FreeVision comes with a balun that actually mounts to the antenna, not dangling free like more antennas we know (just about all of them). It also comes with that short piece of coax about 5 feet long which works for indoor or camping with the antenna near the receiver.

I would dare say, give 10 people both antennas and the FreeVision would win before it's ever mounted just from the ease of construction but then win again on how easy it is to mount.

But remember, this is not a YA-1713. It's not an XG-91. Both the FreeVision and the HD-1080 are urban and near suburban antennas meant (in my opinion) mounted about 10 to 12 feet off the ground. Or as the FreeVision just hung on an outside wall.
 
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IDRick

DTVUSA Member
#34
I had a chance to do a quick test up on the roof today with the FV-HD30. I have three stations that are LOS, 30 miles due West, and NM's in the 50 to 55 dB range. The FV was mounted ~12 AGL. Margin to dropout ranged from 36 to 40 dB range for the three channels. Received signal can be approximated by adding ~14 dB (losses in receiver + cable) to dropout margin. I have tested my mclapp DIY antenna at this location many times. Results were about what I would expect, given the lower gain of FV relative to a mclapp 4-bay. I will be doing additional testing at my son's apartment over the Christmas holiday. He has 15 channels within 20 degrees, LOS, and 10 to 11 miles away. He also lives on the fourth floor so should be able to acquire enough signal to feed two tvs without amplification.
 

Piggie

Super Moderator
#35
If I remember his TVFool, he would be hard pressed to run an amp, unless he does indoors before a passive splitter. Even then he might have to have 100 ft of coax.

Even 100 ft of coax is only going to loss about 5 db and a splitter lets say it's awful another 5 db. With the TVFool report I saw, that should leave his main stations around 50 db NM at the end of the coax.

I feel more confident to say after my tests, seeing a 27 db NM station lock reliably into the Sylvania portable, your son should have no problems with signal strength.

I will be awaiting the test at his house.
 

IDRick

DTVUSA Member
#36
Interestingly, I shared my son's TVfool with Hans when I asked for the FV-30 specs. He suggested that I may need to use a HDA-100. IMO, it shouldn't be necessary. A mclapp 4-bay could bring in plenty of signal, but alas, my son doesn't want an antenna that large in his living room. Understandable actually.... :)
 

Piggie

Super Moderator
#37
Interestingly, I shared my son's TVfool with Hans when I asked for the FV-30 specs. He suggested that I may need to use a HDA-100. IMO, it shouldn't be necessary. A mclapp 4-bay could bring in plenty of signal, but alas, my son doesn't want an antenna that large in his living room. Understandable actually.... :)
If he is inside Rick, he will loose 10 db? As you now know owning one or at least one in your hand, it's small enough to fit in a window behind drapes.

I didn't know Winegard made that little amp. Is it new? Or was I blind?

Well we don't know the how much signal that amp can stand. The HDP269 is a few bucks cheaper and has plenty of gain to be used as a distribution amp. Just one more short piece of coax over the HDA-100 to make the HDP269 a distribution amp of 12 db. It would lower the system noise at your kid's house more than likely also. Then again if it's not needed when you try the antenna, it's not needed.
 

IDRick

DTVUSA Member
#38
Piggie,

AFAIK, the HDA-100 has been around for awhile. It does have a low NF (3.0 dB) and 15 dB gain. The CM 3410 is a better deal though (2/3rds the cost, similar gain, and lower NF at 2.7 dB). The antenna will likely end up in the SE corner of the apartment on the south wall (above his HDTV). This will minimize building penetration. I suspect that the distribution amp would act similar to a pre-amp when connected that close to the antenna. Since he has strong signals, the HDP is the better choice a distribution amp acts like a pre-amp when installed within 10 feet of the antenna. Actually, the hdp269 would be my first choice, I was only reporting what Hans suggested. Hopefully, the need for amplification is a moot point...

The whole purpose of this exercise is to provide a reliable signal on his two favorite channels (ch 7 and 13) up in the bedroom loft. He experiences occasional breakups with these stations up in the loft but not on the main floor when using a rabbit ear/loop non-amplified indoor antenna. The FV has large negative gain on ch 7 (-10.3 dB) and ch 13 (-7.5 dB). The strong local signal will be reduced by negative antenna gain and environmental loss (mostly building penetration). I plan on testing out on his deck and in the living room. We'll go with whichever location gives us the best signal. I'm set up to install in either location.

Will let you know how it works out.

Best,

Rick
 
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Piggie

Super Moderator
#39
Piggie,

AFAIK, the HDA-100 has been around for awhile. It does have a low NF (3.0 dB) and 15 dB gain. The CM 3410 is a better deal though (2/3rds the cost, similar gain, and lower NF at 2.7 dB). The antenna will likely end up in the SE corner of the apartment on the south wall (above his HDTV). This will minimize building penetration. I suspect that the distribution amp would act similar to a pre-amp when connected that close to the antenna. Since he has strong signals, the HDP is the better choice a distribution amp acts like a pre-amp when installed within 10 feet of the antenna. Actually, the hdp269 would be my first choice, I was only reporting what Hans suggested. Hopefully, the need for amplification is a moot point...
Yeap, I got the idea of your post that it was Hans suggestion. It does take one less cable than using HDP269, cleaner indoor install with only 3 db more gain, not likely to make or break an installation. But I agree, hopefully amplification will be moot.

Brings up a good question, maybe another thread, does an amp lowering the noise of the system do as much good on VHF as UHF, and not theory, but actual trials.

The whole purpose of this exercise is to provide a reliable signal on his two favorite channels (ch 7 and 13) up in the bedroom loft. He experiences occasional breakups with these stations up in the loft but not on the main floor when using a rabbit ear/loop non-amplified indoor antenna. The FV has large negative gain on ch 7 (-10.3 dB) and ch 13 (-7.5 dB). The strong local signal will be reduced by negative antenna gain and environmental loss (mostly building penetration). I plan on testing out on his deck and in the living room. We'll go with whichever location gives us the best signal. I'm set up to install in either location.

Will let you know how it works out.

Best,

Rick
Well you will be the acid test on VHF performance of this antenna. As noted my review didn't think yes or no on the VHF of this antenna.

It's supposed to be about 60 degrees at the hottest part of the day tomorrow. I was given a 3 element high band beam over a decade ago. I think it should still work fine and should create a good baseline to compare the FreeVision. And if the signal meter I ordered from JER works as good as reviewed here on this forum, I might be giving better answers comparing the HD-1080 to the FreeVision. After I decided to order it I didn't put up my 4221A on the test rig, mainly because I am hoping the meter is much more revealing than the signal quality meter on my TV and CECB boxes.

However, the more I play with antenna for DTV, the more I am finding don't count out an antenna based on specs. And on the other side, don't think that big huge monster with a gazillion db of gain will give you that much more consistent of a signal.

I am getting more and more inclined without having a spectrum analyzer to just put up the antenna and see how it receives. Leave it up for several days so any weather conditions change, probably at least 3 days minimum before saying something works out 80 miles no sweat, which I have seen so many times it drives me crazy. Had I wanted to make crazy claims on the HD-1080 I could have said wow, this thing rocks, picking us WESH at 83 miles and 2 edge! wow..... wow nothing, it was an almost stationary warm front over central and north central FL. But one thing that does boggle my mind, since I can see Gainesville and Jacksonville VHF on the quality meter (below lock) why WESH which is 22 miles farther away at 83 miles is the strongest VHF on the HD-1080. All the VHFs on the FreeVision were about the same as the HD-1080, with the exception of WESH on ch11. The Winegard polar plots on the antenna explain part of it, but still I get the occasional lock on WESH even now the conditions are gone. Occasional means a few seconds a minute or maybe a minute or two out of ten minutes, where as the other VHF's here never ever lock. But I saw this here 3 years ago when first playing with a YA-1713 on the same test rig. Weird. The only possible explanation is that WESH is but moreover the 2 edges are at a distance that puts something of a signal at low heights in my yard. A refraction of sorts, maybe.
 

Piggie

Super Moderator
#40
Ok, the tests continue. Today between household chores on a day off I took down the HD-1080 and put up an unknown 3 element beam. It "might" be an old Archer? Each end cap on the beam is bright blue with a capital A surrounded by a circle. It's definitely VHF high band.

I used the HDP-269 as the distance from my test stand to my receiver is about 100 ft of RG6 and old, not real good, so it would probably loose 3 to 5 db without the amp (I have to use two 5ft jumpers to reach also).

Director 28" long

Driven 26.5" (12 3/8 each) long

Feed 3/4 inches from the end near boom
The 2 inches per side (wire with 3 sides)
The balun (or 300 ohm lead) is attached where each driven element
half meets this 3 sided trapezoidal wire with the longest side of the trapezoid missing (it would be the distance between the 300 ohm output wingnuts if there). I have seen this feed system sometime in the past and can't remember what it's called.

Reflector 29" long

Dir > Driven 7" spacing
Driven > Reflector 11" spacing

If you take the driven elements tip to tip they are tuned to 211.6 MHz. That is really close to the carrier frequency of Ch 13. However due to the strange feed system I don't think this is accurate, because looking at the antenna the director is longer than the driven element.


If you take the director speaking of it. It's 28 inches long. Now "assume" even though it's aluminum tubing like a modern outdoor antenna and not wire, that it's .95 of the wavelength in space to be a dipole. Then about .95 again to be a director. Some pretty general assumptions but have to use something. That works out to 190.3 MHz. The high part of Ch9, very close to the center of the band.

Doing the same on the reflector but remembering it's about 5% longer than a dipole and a dipole is about 5% shorter than free space 1/2 wave. So it's 29 inches or about 203.5 MHz.

Odd for a commercial yagi. Most of them are about channel 13 on their directors and channel 7 on their reflector, with the driven element as broad as possible.

But there is nothing to this driven element that makes me think it's very broad banded.

Also note the odd spacing of the elements which probably throws off my element length calculation off by maybe as much as a channel, maybe 2.

The reflector spacing is almost twice the spacing of the director from the driven element.

I am though leaning toward this antenna if not designed to be single channel (probably not) but more responsive on ch 9 through 13.

So I tried it on all my VHFs and Jacksonville one just needs to be a long way off the ground (at least 25 to 30 ft) and my 11 ft test setup just didn't get a signal.

However I pointed it WESH on ch 11 and WNBW on Ch 09.

So let me make another huge assumption and use the center frequency of ch 10 to compute the spacing.

Free space wavelength is computed them using 195 MHz or 60.5 inches.

Then 7/60.5 is about 0.12 wavelength (rounding) and 11/60.5 is about 0.18 wavelength. Most 3 element yagis are more like about 0.15 to 0.2 for the director to .2 to .25 for the reflector. Without a computer modeling program it's impossible to say how this spacing affects the bandwidth or center frequency.

Most 3 element yagis have 5 to 7 dbd of gain.

The results were impressive but then again, I can only speak to an antenna testing it this way after 3 days usually enough time for weather tropo to change.

But today WNBW surprisingly came in right about 60 percent on a scale that takes 50 % to lock. I tried the HD-1080 today before I took it down and it only hit 40% on WNBW. Channel 9.

WESH on Ch 11, was coming and going on the HD-1080 just between about 45 to 50 (when it peaked it would lock but only every few mintues for a minute and still breaking up.) When I pointed the 3 element yagi at WESH, it hit held 50% just just just barely locking.

If I were to guess at the gain of this over the HD-1080 I would say it's 5 to 7 db.

I was very surprised WNBW came in that good. I didn't turn my main array at it, but instead I am going to see how the signal holds over a few days, and probably sometime tomorrow I will turn the main array at WNBW. It's been 6 months since I turned it toward WNBW and it was poor, not staying above lock. This is why staying above lock today on a 3 element yagi shocked me.

But I also heard about a month ago, they fixed a problem in the WNBW transmitter that it could not run full power. Also as Trip pointed out, since no one I know (didn't ask their engineer) seen it's output on spectrum analyzer to know it it had a high MER (lots of errors transmitted) or it's a clean signal. Something that also may have been fixed if they had transmitter problems.

If you look back at my 11 ft TV Fool

Note WNBW is LOS and 14.7 db NM when (at least in the past) didn't fade below lock, and only time will tell if once again I tested an antenna when conditions were good.

But how to I see WESH when it's rated -10.2 db NM. Even if the yagi has 7 dbd, or about 9 dbi, that is still below 0 db NM. Then again, just like when the HD-1080 locked WESH consistently, it didn't after about 4 to 5 days.
Probably best to leave this yagi running at least over the weekend to see if WMBW stays. If it does, then I should use it with an AB switch to augment WTLV NBC on ch 13. However unless their transmitter really has been bad a long time or with a high MER, and now it's fixed, I except WNBW to fade before the test completes in say 5 days at least.
 
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