I have a 1970s-era Canadian Radio Shack 4-bay Hoverman. How does that compare to the Gray-Hoverman design? (I'll try to remember to take a picture of it tonight so I can post it.)

Right now it's sitting on the corner of a second storey room in Nepean. I can barely get WNPI analog with it, and I can see 'whiter' snow on digital channels 23 and 38. (Of course, the snow is 'very' white' on local digital channels 22 and 25.) [This was before WCFE 38/57 had their recent 'ice-chunk-fell-on-the-transmission-line' accident in the last week or so]

I hope to get an ATSC tuner for my Mac within a month, so I'll be able to see if I can actually get WCFE or WNPI.

TVl

I have a 1970s-era Canadian Radio Shack 4-bay Hoverman.tvlurker,

Wow, an actual Super G-1483 !!

I would be very interested in the actual dimensions of your 4 Bay Hoverman.
This would add a significant amount of info to this project, and allow me to make modeling comparisons of our DBGH to the original Super G-1483.

The measurements (mm) I would like to know are:

1. The length of the diagonal elements of the array. Are they all the same length. or are some smaller?
2. The length of the horizontal stubs. (The modeling results show that the upper UHF freq gain is sensitive to this length)
3. The vertical distance between the array mounting points.
4. The array to reflector distance.
5. The length of the collinear rod reflectors. Are the middle ones shorter?

It would be very interesting to compare those measurements to the posted DBGH design info, and to run EZNEC with those measurements.

I'm in Bells Corners and am also hoping to get good reception on WNPI Norwood.
My tests on SBGH and DBGH have to wait for all this @# snow to melt, and melt slowly I hope !!

I'll measure the antenna tonight. It's a bit bunged up. It spent most of its youth in my parent's attic in Montreal, although it did spend a few years on their roof. ( I first put it in the attic, and then realized that the universal mount for the 20 foot mast that used to be on the house when we bought it the late fifties was still there, so I put up a short 6 foot mast. It returned to thew attic when the roof got reshingled. I also had a RadioShack deep fringe UHF yagi I rescued from the attic. It was positioned for WCFE, while the hoverman was for Mt Mansfield 22/33 and later 44.)

TVl

Looking forward to the photo too, tvlurker! This is like an archaeological discovery! :)

http://farm3.static.flickr.com/2091/2329912727_70ed98df55_b.jpg

Actually, it looks more or less like the classic Hoverman described in the WTFDA article here. http://www.wtfda.org/images/stories/pdf/hoverman.pdf

The measurements (mm) I would like to know are:

1. The length of the diagonal elements of the array. Are they all the same length. or are some smaller?

They seem to be 180 mm for the 2 interior diamonds. The top are 170, with a 31 mm 90 degree bend outward.

See the picture below.

The diamonds are not symmetric wrt the reflector rods -- the top extensions do not extend beyond the top rod, but the bottom ones do. Consequently, the transmission line feed point is not at the mid point of the reflectors, but only a few cm above the second reflector from the bottom. (This may be due to some damage to my antenna, since the one in the WTFDA article looks symmetric)

2. The length of the horizontal stubs. (The modeling results show that the upper UHF freq gain is sensitive to this length)

This Hoverman has vertical stubs 130mm high, which extend to the same height as the 170 mm 45 degree stubs.

3. The vertical distance between the array mounting points.

There is only one array, since this is a "3-bay" (two diamonds, and two half diamonds)? I think you'll need the picture.

4. The array to reflector distance.

about 120mm. I'll get you a better measurement on the weekend.
Note that the reflector rods are behind the vertical boom, which is about 25mm, square.
There are metal two spacers between the metallic boom and the 2 insulators holding the driven elements. They're held in place by (very rusty) steel rivets.

5. The length of the collinear rod reflectors. Are the middle ones shorter?

Top and bottom: 355 mm
Middle two: 253 mm

The reflectors are insulated from the boom. The horizontal distance between each collinear reflector is 44mm.
The top and bottom reflectors are about 245 or 247 mm from the inner ones. The two inner ones are 250mm from each other.

Hope this helps.
TVl

Tvl,

This is truly ..." A Blast from the Past !!"....Wow ..!!
Thanks Tvl for the pic and the dimensions.

As Stampeder mentioned "This is like an archaeological discovery!"
This will provide very valuable info on the early commercial Hoverman antennas.

This is an interesting variation on the Single Bay Hoverman.
Instead of having a horizontal stub at the top and bottom as our SBGH, this design has two vertical whisker stubs
and a slightly reduced top and bottom diagonal element with a short 90 degree downward tab.
( ...Hows that for a tongue-tied description...)

I have made a sketch of the array from the dimensions that you gave and from my understanding
here is my current view of the Array and reflectors.
Prior to modeling this I would like to verify that I have the correct dimensions.
Based on my current understanding, there are a couple of points that I need to clarify.

Array
Looks like the array is made from 1/8 - 3/16" solid wire.
I am assuming that the feed-point gap is 44mm or 1.75 inches.
Looking at the driven array only, and assuming that all the bends of the diagonal elements are at 90 degrees,
then the two spacings between the three mounting points for the array would be the same and would be 254mm.
That would make the total height of the array equal to 768mm
[ 130mm (top vertical stub to the first array mounting insulator) +254mm (1st to 2nd array insulator) +254mm (2nd to 3rd array insulator) +130mm (bottom vertical stub)].

Reflectors

These are 4 pair of collinear rod reflectors. Looks like 3/8" tubing.
The top and bottom pair sections are 355mm in length with a 44mm spacing.
The two middle pair sections are 253mm in length with a 44mm spacing.
The top and bottom reflectors are about 245 or 247 mm from the inner ones. The two inner ones are 250mm from each other.

The total height for the reflectors would be 247+250+247 = 744mm.

The picture of your Hoverman clearly shows the total reflector height to be more than the array, but my calculations indicate the array is more than the reflectors. This is obviously wrong and hence my assumption that the array diagonal elements are bent at 90 degrees must be wrong.

Hence the additional info I need, is..
(1) The spacing between the three array mounting insulators ( 1st to 2nd and 2nd to 3rd) I would now expect that to be less than 254mm.
(2) I also would need a measurement of the spacing of all the reflector mounting insulators with respect to the middle array mounting insulator. That would pinpoint the vertical location of the reflectors with respect to the array.

Regards
...Autofils

Tvl,

This is truly ..." A Blast from the Past !!"....Wow ..!!
Thanks Tvl for the pic and the dimensions.


My pleasure. As my wife says, there has to be some benefit from being a packrat.


This is an interesting variation on the Single Bay Hoverman.
Instead of having a horizontal stub at the top and bottom as our SBGH, this design has two vertical whisker stubs
and a slightly reduced top and bottom diagonal element with a short 90 degree downward tab.
( ...Hows that for a tongue-tied description...)

I have made a sketch of the array from the dimensions that you gave and from my understanding
here is my current view of the Array and reflectors.
Prior to modeling this I would like to verify that I have the correct dimensions.
Based on my current understanding, there are a couple of points that I need to clarify.

Array
Looks like the array is made from 1/8 - 3/16" solid wire.

I don't have calipers, but I'll see what I can do.

I am assuming that the feed-point gap is 44mm or 1.75 inches.


I think it might be slightly less -- my notes are at home.


Looking at the driven array only, and assuming that all the bends of the diagonal elements are at 90 degrees,

correct.

then the two spacings between the three mounting points for the array would be the same and would be 254mm.

Sorry I didn't upload the side view pictures.
Only the top and bottom insulators are attached to the boom.
The middle insulator with the feed point is unsupported by the boom.

I also discovered that the to top separator was at a 90 degree angle to the boom, but the bottom separator was angled down somewhat.
I restored it to a 90 degree bend after the picture above was taken, so that now the bottom whiskers and tab-terminated angled elements are level with the bottom reflector, just like the top ones are level with the top reflector.


That would make the total height of the array equal to 768mm
[ 130mm (top vertical stub to the first array mounting insulator) +254mm (1st to 2nd array insulator) +254mm (2nd to 3rd array insulator) +130mm (bottom vertical stub)].

Reflectors

These are 4 pair of collinear rod reflectors. Looks like 3/8" tubing.
The top and bottom pair sections are 355mm in length with a 44mm spacing.
The two middle pair sections are 253mm in length with a 44mm spacing.
The top and bottom reflectors are about 245 or 247 mm from the inner ones. The two inner ones are 250mm from each other.

The total height for the reflectors would be 247+250+247 = 744mm.

I'll double check the totals tonight.

The picture of your Hoverman clearly shows the total reflector height to be more than the array, but my calculations indicate the array is more than the reflectors. This is obviously wrong and hence my assumption that the array diagonal elements are bent at 90 degrees must be wrong.

I'll double check, since the 90 degree angle check I did last night was before the 'readjustment'.

Hence the additional info I need, is..
(1) The spacing between the three array mounting insulators ( 1st to 2nd and 2nd to 3rd) I would now expect that to be less than 254mm.
(2) I also would need a measurement of the spacing of all the reflector mounting insulators with respect to the middle array mounting insulator. That would pinpoint the vertical location of the reflectors with respect to the array.

Regards
...Autofils

Here are the modeling results for the commercial 4 Bay G1483 Hoverman
Many thanks to TvL for providing the photo and measurement data.
( This is a long post)

Some Background
=============
TvL's photo of his Hoverman antenna, has quite an interesting variation from the Hoverman patent #3148371.

Instead of having a horizontal stubs at the top and bottom as described in the patent, this design has two 130 mm vertical whisker stubs added at the top and bottom array mounting insulators and slightly reduced top and bottom diagonal elements (170mm), each with a 31 mm tab extension bent at 90 degrees.

This antenna uses 4 pair of collinear rod reflectors with lengths of 355mm and 253mm.
These are the same lengths as described in the Hoverman patent (14"and 10")

From TvL's measurements, the collinear rod reflectors are not symmetrical, but are offset by a small amount.

He also pointed out that his Hoverman is very similar to the photo in the VUD Sept 82 article "The Hoverman". http://www.wtfda.org/images/stories/pdf/hoverman.pdf

Indeed, if you look closely at the photo, you can see vertical stubs at the top and bottom of the left array element.
Due to the angle at which the photo was taken, the right array stubs are not visible, but they are there!
The Vud Hoverman does not have the tab extensions, and the collinear reflectors are symmetrical and follow the patent description.

Based on the above, I conclude that we can declare TvL's Hoverman, to be the Radio Shack 15-1627 that is mentioned in the VUD article and is a G-1483 4 Bay variation.

Modeling Analysis
=============

I made two models of TvL's Hoverman. One with the dimensions as stated with non-symmetric collinear reflectors and another with symmetrical reflectors as described in the patent. The element diameter used was 1/8" for the array and 3/8" for the reflectors, and I used 100mm reflector spacing ( the same as SBGH)

TvL's G1483 Hoverman models
http://i258.photobucket.com/albums/hh262/autofils/YZModelview_2.gif


Modeling Results
============

The following photo shows the Net gain for TvL's G1483 Hoverman, with symmetric and non-symmetric 4 pair rod reflectors.
Comparison plots are given for the SBGH 6 pair collinear rod reflectors as well as the Channel Master CM-4221.

Net Gain is the model's raw gain corrected for impedance mismatch. As k6q6v points out on his web site hdtvprimer.com, net gain is the only fair way to compare different antenna designs, since the raw gain does not account for any impedance mismatch.

Net Gain TvL's G1483 Hoverman

http://i258.photobucket.com/albums/hh262/autofils/TvlNetGain.gif

These results show that the TvL's G1483 has lower gain than the CM4221 and our SBGH 6 pair version.
The difference between Tvl's symmetrical and non-symmetrical reflectors is very slight.

The large dip in TvL gain around Ch 55 is due to the poor swr as you can see in the next photo.

TvL's G1483 SWR

http://i258.photobucket.com/albums/hh262/autofils/Tvl-SWR_2.gif

Based on these results, it would seem clear that the better gain characteristics of the CM4221, resulted in the disappearance of this early commercial 4 Bay Hoverman (G1483) antenna for the UHF band of Ch14 to 69.

The only other commercial Hoverman antenna that this project is aware of is the AntennaCraft Super-G 1483 (8 Bay). This is (or was) available from SummitSource.com. If anyone has this antenna, please contact me or anyone associated with this forum regarding measurement info useful for modeling the Super-G.

Just an aside about our SBGH and DBGH, in case some are confused about terminology...
To use the same terminology as the commercial antennas, our SBGH is a 4 Bay and the DBGH is a 8 Bay.

Regards
...Autofils

Based on these results, it would seem clear that the better gain characteristics of the CM4221, resulted in the disappearance of this early commercial 4 Bay Hoverman (G1483) antenna for the UHF band of Ch14 to 69.


Well, this explains a lot.

I had originally purchased the RS Hoverman to pick up 22 and 33 from Mount Mansfield (in Montreal). When WCFE 57 came along, I had trouble picking it up with the Hoverman off angle, so I bought a Radio Shag Deep Fringe UHF Yagi just for 57.

With -10dBi gain on channel 57, no wonder we needed the second antenna!

For cases where the hoverman is used as an indoor antenna, how would a tuning circuit at the feed point improve the SWR?

Well, this explains a lot.

I had originally purchased the RS Hoverman to pick up 22 and 33 from Mount Mansfield (in Montreal). When WCFE 57 came along, I had trouble picking it up with the Hoverman off angle, so I bought a Radio Shag Deep Fringe UHF Yagi just for 57.

With -10dBi gain on channel 57, no wonder we needed the second antenna!

For cases where the hoverman is used as an indoor antenna, how would a tuning circuit at the feed point improve the SWR?

TvL,

Its very difficult to make any swr improvements on this design. The poor swr is due to the array design. If you want to make any improvements, it's easier to replace the array elements with new ones, bent in accordance with the SBGH array dimensions and keep the existing 4 pair collinear rod reflectors.

You could use #14 Cu wire, coat hanger wire or Al #9 wire. Just carefully drill out the rivets and mount the new array elements with suitable nut and bolt hardware.

But then, you might be destroying an antique, since there are probably not many of these around.
If this new design sparks significant renewed interest in the Hoverman, your old Hoverman just might become a valuable collector item.
Being a pack-rat, myself, I'd keep it as-is and watch its value sky rocket. :o
( Hey, it's possible...it could happen... keep checking on Ebay...)

Instead, I'd either build Keo's indoor folding version, or if it's for the attic go for a split-screen reflector using tin-foil.

There is very little information available anywhere on the Hoverman antenna. The only reference to any commercially manufactured Hoverman antennas seems to be in the article (PDF) The Hoverman, VUD Sept 1982, which mentioned a 4 bay Hoverman made by AntennaCraft named the model G-1483 and which was also made for Radio Shack as the model 15-1627, seen in this photo courtesy of tvlurker:


[poltergeist voice]Its back.............[/poltergeist voice] $46.95 at SummitSource.com

http://www.summitsource.com/antennacraft-8-bay-uhf-antenna-hdtv-guaranteed-to-out-perform-all-other-outdoor-18-elements-tv-aerial-for-local-offair-digital-fringe-reception-red-zone-part-super-g1483-with-coaxial-cable-p-6356.html

http://img149.imageshack.us/img149/2852/summitsourcean1483uc1.jpg

Judging by that picture of the commercial Super G-1483 Hoverman above, does it look like the bottom Hoverman is smaller and more squashed than the top one ? Or is it just an optical illusion ?

300Ohm

The super G-1483's photo from summitsource.com is taken at a relatively sharp angle, and that makes it difficult to "ball-park" the dimensions.

This was first reported in post #19 by Oneoldude, and I made a rough ball park estimate in post #22.
http://www.digitalhome.ca/forum/showpost.php?p=675467&postcount=19

http://www.digitalhome.ca/forum/showpost.php?p=686592&postcount=22

Here is a summary of Super G-1483 data from post #22.

-----------------------------------------------------------
Boom length = 60 inches
Max Width = 30 inches
Depth = 5 inches
UHF Ch 14-69 with 35- 60 mi range; Avg Gain 11dB
Number of Elements = 18

If you consider that the reflectors are co-linear, then reflectors are 7x2=14 elements and each array has 2 elements; giving a total of 14+4=18 elements.
The total width of the biggest co-linear reflector is 30 inches.
The maximum reflector to array spacing is 5 inches, probably something less.

Since the total height is 60 inches the height of each array + gap between arrays is 60 inches. Scaling from the picture, looks like the gap between arrays is 3-4.5 inches, with each array at about 27.75 to 28.5 inches.

This would result in a length of 6.54 to 6.71" for the array's diagonal elements.

A couple of points about this SuperG-1483:
The estimate for the length of the array diagonal elements is shorter than my modified Hoverman. This is probably due to their claimed UHF range up to Ch 69. With the coming changes to the frequency spectrum, need only to go up to Ch 52!

The SuperG-1483 only has 7 co-linear reflectors.

-----------------------------------------------------------------------


The above ball park estimates assumed all "diamonds" were the same size and all diagonal elements were bent at right-angles.


Your observations that the bottom bay might be smaller, might well be the case, as this would be a better approach to extend the band-width to Ch 69.

So it's quite possible that this Super-G design made two variations from the original Hoverman patent:

1. The diagonal half-angle bends are something less than 45 degrees. i.e the "diamonds have been squished down a bit. (?)
( My modeling shows that the gain is reduced for diagonal bends less than 90 degrees.)

2. To extend the band-width to include the Ch 52 to 69 range, one "diamond" is smaller. (?)

The only way to know for sure, is to measure the dimensions of an actual Super G-1483.
Any lurkers that can provide measurements of the Super G-1483?


Comparative Data ........ Super G-1483 ....... DBGH GPLv3

Total height (in) ................... 60 . ................... 65
# Reflector Pairs .................... 7 ..................... 11
Max width (in)...................... 30 .................... 24.8
# Elements ......................... 18 ..................... 26
Reflector Spacing (in)............ <5 .................... 4
UHF Band-width .................. 14-69 ................. 14-51

So my wife and I own a condo where my mother-in-law lived until recently, when she moved to a retirement home. We've spent the past few months sprucing it up for resale. The complex was built in 1971 and each unit has a wall box with two coax cable stubbed in, presumably from an antenna on the roof. I had never paid a lot of attention because everyone in the place (including my mother-in-law) had cable, or a dish attached to their deck railing.

Yesterday as I was taking some trash to the dumpster, I actually thought to look at the roof. Much to my surprise... COULD IT BE? YES! Right above a standard, 70s-era triangular rod-type antenna (like this: http://rsk.imageg.net/graphics/product_images/pRS1C-3056853w345.jpg), was a Hoverman. It looked just like the photo on the front page of the GH site (http://www.digitalhome.ca/ota/superantenna/radio_shack_hoverman.jpg)

Well... except that two of the eight rod reflectors were snapped and dangling pathetically downward. No doubt the doing of a bird looking for a perch. ;)

While I never tried it, I'm now guessing that the two coax cables are for VHF and UHF respectively. There is a wall plate on the box which has two coax connectors on the back, and on the front has two small screws. I am guessing now that you would have one of those little boxes that has two "C" connectors, one for VHF and one for UHF, and a coax output... and that you would connect one to each screwpost and then run coax to your TV.

But obviously no one in the building is using the antennas, since they are in disrepair. I wonder if they'd give them to me if I asked. :cool: There are actually 5 buildings in the complex, and they all appear to have this same antenna set-up... so there are 5 Hovermans in all!

Anyway... just thought I'd let everyone know that the old "original" design was spotted, still in existence, in public. :D

I see where SummitSource.com is selling an AntennaCraft version of the DBGH!

I see where SummitSource.com is selling an AntennaCraft version of the DBGH!They're selling three different Hoverman (original) variants, model numbers:
an1483
anuhs2
ansg16
Interestingly the actual Antennacraft web site does not show these in their product line, so perhaps Summitsource is selling old stock.

ansg16


Theyre saying thats a 16 bay antenna, but I cant figure out why they say that.

Good catch... makes no sense!

I just Googled "ANSG16" and only Summitsource comes up in the very few results.

Theyre saying thats a 16 bay antenna, but I cant figure out why they say that.

I guess Stampeder does not allow pasting url links for commercial stores like summit-source, so I will attempt to describe it.

The ANUHS2, is a double horizontal GH type antenna, using what appears to be two GH4 bays.
Regardless of how they calculate 16 Bays, they are selling it at $19.95, plus they throw in 50ft of coax... free!!
You can't build a single bay for that price, based on some of the posts I've seen by DIYers that have built a SBGH gen1, and you get two SBGH antennas, sort of like a "two for one deal" for that price !!

Now that we have the 'cliff attenuation' measurement, it would be very,very... and I mean VERY...VERY .....interesting,
if there was just one person in the USA (S&H is a lot less to a USA destination, than Canada), that would purchase the ANUHS2 and post info regarding two things:

1. The physical dimensions of the ANUHS2 ( lengths, spacings and element diameter, etc); such that it could be modeled in 4nec2 !

2. Make some comparative "cliff-attenuation" measurements !!

My guess is that your $19.95 would likely be well spent. It's likely to be a decent antenna.
Plus you would really add significant info to the knowledge base for this type of antenna design.

====================================
Added this Edit
If you don't wish to purchase the antenna, but would like to contribute to the knowledege base,
you could send a small donation to my paypal account, to help reduce my costs, and
I'll purchase one and use the cottage test site (see Gen2 thread post#399)....
( http://www.digitalhome.ca/forum/showpost.php?p=789475&postcount=399 )

Shipping weight is 10lbs, S&H via Canada Standard (lowest cost) is $25.59. My total cost is $45.54US funds.
=====================================

AND NO !!! I am not affiliated with SummitSource in any Way !!
( ...here is the link....maybe Stampeder will miss it :rolleyes: )

http://www.summitsource.com/antennacraft-stacking-boom-support-braces-for-super-g-1483-uhf-hd-antenna-double-aerial-from-8-bay-to-16-bay-upgrade-boom-support-brackets-part-super-g-1483-with-coaxial-cable-p-7649.html

Am I reading this correctly. It says its just for the braces to stack the antennas. I think its a bit misleading. It says,

AntennaCraft Stacking Boom Support Braces for Super G 1483 UHF HD Antenna Double Aerial from 8 Bay to 16 Bay Upgrade Boom Support Brackets, Part # Super G 1483 | With Coaxial Cable