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post #1 of 31 (permalink) Old 2017-05-28, 11:18 PM Thread Starter
 
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re: Hoverman mods

Hi: Guys.

I just scored 2 new in the box Radio Shack Hoverman's.

Part # is 15-1627

I now have three of these antenna that are NOS.

I just had a few questions for you guys.

1: what mod should I do to improve the performance
of these antennas ? I'm not interested in VHF only UHF.
I see the other Hoverman antenna legs
at the top & bottom of the driven elements extend out,
where the Radio Shack version just curves up.

2: The reflector elements are all non grounded on my version
as they are on plastic insulators. Do these have to be insulated
or can I use reflector elements that are directly connected to
the vertical support.

3: will a stacked pair of these Radio Shack Hoverman's outperform
2 stacked CM4221HD's ?

4: Should I use two baluns & a two way splitter to combine the two
antennas as I'm going to stack then in a vertical fashion.

5: I've seen the commercial versions stacked & using a stacking bar
to connect the two antennas, is this better than using two baluns ?

6: Is the gap between the two sides of the antenna critical ?
I mean the distance between the spot where the antenna lead go's
and the space between the rest of the active elements.


Any input would be greatly appreciated guys.

Thanks

Bruce.

Last edited by DXING.Bruce; 2017-05-28 at 11:37 PM. Reason: More details
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post #2 of 31 (permalink) Old 2017-05-29, 08:15 PM
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But before we can precede, we need to know EXACTLY the LENGTHS of each Section of the Zig-Zag Structure including the outer Section LENGTH and ORIENTATION....as well as the Overall LENGTH of the Reflector Rods incl. the size of the Mid-Point GAP....and the Reflector-to-Bowtie Separation....and lengths/orientation of whatever other filligree that might have been added onto the Original Hoverman....if your's doesn't EXACTLY MATCH one of the following, please post some pictures.

=========================================
Doyt R. Hoverman's original design for a television antenna was granted US patents #2918672 on 22 Dec 1959 and #3148371 on 8 Sept 1964.

The Hoverman [and later SBGH] was based on Henri Chireix's earlier Patent [12Apr1928] for a Totally Symmetric "4-Square" [i.e. 4-Segment] Zig-Zag Antenna in which ALL Segments are the same Length (7-in) at exactly 45-deg Angles, including the outside "Zag's" which turned back around towards the middle, also at 45-deg Angle. It was determined that the Optimum Segment Length was between 10.0 to 10.2-inches, which provided higher Gain than a Hoverman, but at the expense of Gain Roll-off due to narrower Bandwidth:
UHF Chireix Antennas (NO Reflector)

In Doyt Hoverman's Type-1 Hoverman Antenna, ALL of the Dimensions were SMALLER (only 7-in), also with 45-deg Angles, except he ROTATED the Top and Bottom Segments HORIZONTALLY OUTWARD (also 7-inches), as analyzed here:
Hoverman Type1 (NO Reflector)

Hoverman Type-2 was identical, except FOUR Reflector-Rods were added, with a Mid-Point Gap, as analyzed here:
Hoverman Type 2 w 4 RRs - Doyt's

But the Radio Shack R-S 15-1627 continued to use 7-in Zig-Zags, except they actually reverted BACK to the CHIREIX design, with the Top & Bottom Z-Z Segments pointing OUTWARD at a 45-deg Angle [5.4-in plus 1.0 in Vertical Spur]. They ALSO ADDED some Short Vertical Stubs at the Top and Bottom, probably to adjust SWR rather than improve Gain. I posted analysis here:
Hoverman Type 2 w 4 RRs - Radio Shack

First of all, we need you to verify whether or NOT what you have is truly the R-S 15-1627 as depicted in fol. 1971 Allied R-S Catalog:
1971 Allied Radio Shack Catalog Low-res page 292 of 464

If so, carefully verify that it TRULY has the fol. Dimensions (taken from the 4nec2 File cited above):

CM Length of each Diagonal sub-section = 7 inches, Gap at Feedpont = 1.5 inches.
CM Split Rod Reflectors with Center Gap of 1.5 inches and with the following OVERALL Lengths:
CM - Top and Bottom = 14" + 1.5" + 14" = 29.5"
CM - Middle = 10" + 1.5" + 10" = 21.5"
CM - Reflector-to-Bowtie Spacing = 4 inches

=========================================
Note that I posted a photo: "HOVERMOON" of my similar, yet slightly DIFFERENT Hoverman...let us know if you have THIS Variation.....I have the Dimensions but have not yet posted 4nec2 Results....it's still hanging in my Garage.

One of the original SBGH's [e.g. Autofils Version] increased all 45-degree Angle Zig-Zag Lengths from 7.0 to 7.07-inches (negligible difference) and more importantly changed Horizontal Stub Length from 7.0 to 5.0-inches. This improved overall Gain, as well as extended it to include Ch51 by SHORTENING the Horizontal Stubs:
Antennacraft G-1483 Hoverman Type 2

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands
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post #3 of 31 (permalink) Old 2017-05-30, 02:16 AM Thread Starter
 
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Thanks for the reply. I will measure the antenna & get back to you.

I can't upload pics for some reason as it asks for a link, I can't just
copy & paste a pic.

The antenna is the last version Radio Shack sold with the 4 blue insulators
for the 4 reflector elements.

I did measure the gap at the 300 ohm connection and it was 2 and a eighth inches
center to center of the rivets.

It has the two sets of tuning stubs the top & bottom. The driven elements don't
go out straight they are just bent up and are about 1" long
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post #4 of 31 (permalink) Old 2017-05-30, 11:27 AM
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Quote:
I can't upload pics for some reason as it asks for a link, I can't just
copy & paste a pic.
You can create your own photo album on this forum and link to it using the BB code as directed. Go to your User CP.

The limit on size is 600 x 800 pixels and 100K, so crop closely for max detail. You can also use an image host like photobucket to store your images.
How to create a photo album for use on the Digital Forum

Edit:
I see they changed the file size:
Maximum File Size per Picture 151.1 KB

If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 2017-05-30 at 06:31 PM.
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post #5 of 31 (permalink) Old 2017-05-30, 12:08 PM Thread Starter
 
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Here are three pics of the antenna.

I will measure & give more details in my next post.

http://www.digitalhome.ca/forum/album.php?albumid=2521

http://www.digitalhome.ca/forum/albu...ictureid=14225

http://www.digitalhome.ca/forum/pict...ictureid=14233

Sorry if you can't see the pics, I'm really not very good at the computer thing.
I'm very old school in that I don't even own a cell phone.
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post #6 of 31 (permalink) Old 2017-05-30, 06:36 PM
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Quote:
Sorry if you can't see the pics, I'm really not very good at the computer thing.
It took me a while to learn it too.

I edited your photo, turned it vertical, and put it in my album. To make it show in a post, I used the second line below the photo called BB Code. I think this is what holl_ands wants to see:


If you can not measure it, you can not improve it.
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post #7 of 31 (permalink) Old 2017-05-31, 01:45 AM Thread Starter
 
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Here are the measurements guys.

I believe the driven elements are made of 1/8" aluminum stock.

The segments of the driven elements are all 7"

The space from the reflectors elements to the driven is 4"

The length of the 2 long reflectors is 13 - 1/4 " ( rivet to end )

The length of the short 2 reflectors is 9 - 1/4 " ( rivet to end )

the spacing at the driven elements 300 ohm connecting
and all driven element connections is 2 - 1/16 "


I hope this helps.



Any info you guys can give would be awesome.


Thanks.

Bruce.
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post #8 of 31 (permalink) Old 2017-05-31, 09:39 PM
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Quote:
Originally Posted by DXING.Bruce View Post
Hi: Guys.

I just scored 2 new in the box Radio Shack Hoverman's.

Part # is 15-1627

I now have three of these antenna that are NOS.

I just had a few questions for you guys.

1: what mod should I do to improve the performance
of these antennas ? I'm not interested in VHF only UHF.
I see the other Hoverman antenna legs
at the top & bottom of the driven elements extend out,
where the Radio Shack version just curves up.

A1: My Hoverman is SAME as your's, except my Brackets are BLACK. About the only GOOD thing I can say about our Hovermans is that [FWIW], they're 30% SMALLER (i.e. Zig-Zag Lengths = 7-in,whereas Chireix is 10-in...ditto Whisker in Bowtie). I need to modify my 4nec2 Model for the OTHER R-S Version before I can say how well OUR version works (or not). And THEN I'll try a few things to see if I can "inprove" it. Since Hoverman's have limited Bandwidth, what is the Lowest and Highest UHF Channel you WANT???

2: The reflector elements are all non grounded on my version
as they are on plastic insulators. Do these have to be insulated
or can I use reflector elements that are directly connected to
the vertical support.

A2: I'm sure it DOES make a difference since they are Resonant Elements whose Electrrical Characteristics would be CHANGED when connected to an arbitrary amount of extra Metal. I just don't know HOW MUCH....

3: Will a stacked pair of these Radio Shack Hoverman's outperform 2 stacked CM4221HD's ?

A3: Stacking should improve Calculated Gain by about 3 dB [plus whatever Space Diversity Gain might be available]. But I need to run the revised model first....but I'm predicting that they will be fairly close....except for Hoverman's Gain Loss on higher UHF Channels.

4: Should I use two baluns & a two way splitter to combine the two
antennas as I'm going to stack then in a vertical fashion.

A4: NO, too much loss in RF Combiner....I can calculate OPTIMUM Dimensions for a Vertically Stacked Pair interconnected with my HVH (Hollands Vertical Harness) which has ZERO Loss.

5: I've seen the commercial versions stacked & using a stacking bar
to connect the two antennas, is this better than using two baluns ?

A5: Dimensions need to be OPTIMIZED....just any ol' Stacking Bar is likely to DEGRADE performance.

6: Is the gap between the two sides of the antenna critical ?
I mean the distance between the spot where the antenna lead go's
and the space between the rest of the active elements.

A6: YES...Feedpoint Gap is the PRIMARY adjustment to minimize SWR across the Frequency Band of Interest.


Any input would be greatly appreciated guys.

Thanks

Bruce.
See embedded comments above.

BTW: nikiml calculated OPTIMIZED Dimensions for a very large number of G-H Designs.
The closest to the Hoverman is the fol. GH4 with 4 Pair of Split Reflector Rods....except the Lenghts and Angles of the Zig-Zag Segments are allowed to be DIFFERENT, rather than being constrained to be the SAME. This results in a very FLAT Gain of about 13.5 dBi vs Frequency [also low SWR]:
http://clients.teksavvy.com/~nickm/gh_u/gh4_13u4.html

OTOH CM4221HD, with ALL Whiskers the SAME Length (7.9-in), provides the same 13.5 dB Gain at Mid-Band Frequency, but with LOWER Gain on Lower Channels and HIGHER Gain on Higher Channels:
http://imageevent.com/holl_ands/mult...uhfnewcm4221hd

My Free-Form FF4 4-Bay with Double-Angle Reflector allowed ALL Whisker Pairs as well as Inner/Outer Bowtie-to-Bowtie Separation to be DIFFERENT, which ALSO provided fairly Flat Gain vs Frequency [and low SWR]....where the BIG Screen Grid Reflector is pushing up the Gain as well:
http://imageevent.com/holl_ands/mult...dblanglreflopt

PS: I have a Design for an even higher performance FF6 6-Bay Bowtie with Taller Reflector....and Stacked versions of both FF4 and FF6:
http://imageevent.com/holl_ands/mult...6baybowtievdar

So....right now I'm thinking of ALSO running an Optimization where the entire Zig-Zag Wire is REPLACED, which allows each Section to be ANY Length....with the EXISTING Top/Bottom Feedpoint Connection Points being FREE to float along the Z-Axis....and whatever needs to happen wrt Top and Bottom Segments.

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands

Last edited by holl_ands; 2017-06-01 at 01:12 AM.
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post #9 of 31 (permalink) Old 2017-06-01, 12:07 AM Thread Starter
 
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Ok, I look forward to your test results.

I figure these antennas have been around since the 50's
and have not changed a whole lot so how bad can they be.

Many people had them on their roofs & towers in the 50 's
60's 70's & even the 80's so I guess they must work ok.


I will await your results, thank for all your input above as well..


Bruce.
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post #10 of 31 (permalink) Old 2017-06-11, 12:55 AM Thread Starter
 
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Thanks again for all your info.

I only want to use the Hoverman for 14 - 51 uhf.

I want to stack the two antennas in a vertical array.

I guess connecting the two antennas with a straight rod
from the two 300 ohm connections then connect my balun
to the center of the stacking rods is the best bet.


Bruce.
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post #11 of 31 (permalink) Old 2017-06-11, 04:38 PM
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Alternative runs are DONE [5 Re-Optimizations plus 4 for the Existing, Similar Designs....some with and some w/o Reflector Rods], but I need to Copy/Paste Results into Excel Spread Sheet and Generate some Comparison Charts to see WHICH alternative is the least amount of work for the best results.....and YES, some of them work quite well for Ch14-51, other than an inherent tendency for mild Frequency Roll-Off on the Lower Channels (just like most Yagi's).

BTW: It would help to know your TVFool Results to see how well suited they are, depending on WHERE and how Strong your Stations are.....Re-Optimizations done thus far presume all are in ONE Direction....

Vertical Stacking requires Re-Optimizing to determine the Dimensions of the HVH (Holl_ands Vertical Harness) which is needed to Minimize SWR when Interconnected and Maximize Gain across ALL Channels. If you simply Interconnect them without doing the Optimization process, it is very likely to have both High SWR and Gain Hole Issues. I'll do that after we pick a suitable [non-stacked] Hoverman modification.

Antenna Simulations, Overload Calculations, etc: http://imageevent.com/holl_ands
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post #12 of 31 (permalink) Old 2017-06-11, 06:53 PM
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Quote:
BTW: It would help to know your TVFool Results to see how well suited they are, depending on WHERE and how Strong your Stations are
Quote:
Originally Posted by DXING.Bruce View Post
I'm using a 8 bay now that has two adjustable 4 bays.
I'm in east York near Woodbine & Cosburn & my setup is on
a tower up 45'.
I think this is pretty close:
TV Fool

His previous thread:
Feeding stacked array

He didn't know why anyone didn't answer him on that thread. I told him that a lot of people had viewed his thread, but I couldn't figure out why he wanted to do it that way.

He never did a report for me, we just used the one I did.

If you can not measure it, you can not improve it.
Lord Kelvin, 1883
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post #13 of 31 (permalink) Old 2017-06-14, 12:13 AM Thread Starter
 
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Thanks again to all who take the time to answer my questions
and try to help with my antenna setup.

I'm a 1/2 a block east of Woodbine on Cosburn, m4c2w4

I get all Buffalo stations with decent signal although from time
to time they glitch out on me.

I would like to get Ion all the time but I only get it 75% of the time
as it is blocked by the high rise buildings at Main & Danforth.

I'm no antenna expert guys so please forgive me if I
seem clueless sometimes. I just like to experiment to get the
best setup I can & bring in the most stations without having to
use a rotator or antenna switches.

my final setup will most like be using a Channel Master 7775 uhf preamp
then fed into my house & split 3 ways for the 3 TV's in the house.

Thanks.

Bruce
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post #14 of 31 (permalink) Old 2017-06-14, 04:17 PM
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Quote:
I'm a 1/2 a block east of Woodbine on Cosburn, m4c2w4
I did a new report based on that, and picked a house in the middle the block:

TV Fool
Quote:
I would like to get Ion all the time but I only get it 75% of the time
as it is blocked by the high rise buildings at Main & Danforth.
Maybe not. I followed the WPXJ ION green signal line back to your area. I think it just misses the Scotiabank building.







ION is a Tropo signal; it will never be reliable as I showed you in your other thread:

Feeding stacked array

Feeding stacked array

You might be able to improve it, but it will never be 100%.

If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 2017-06-14 at 04:36 PM.
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post #15 of 31 (permalink) Old 2017-06-15, 12:18 AM Thread Starter
 
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Thanks: rabbit73.

I really appreciate all your time & efforts.

That is a really cool aerial view of the main street buildings.

I'm not against using a rotator & directional antenna to pick
up ION on a regular basis but because I will be feeding one tv
in my bed room, one in my Mom's bed room & one in the
living room I don't want my Mom to lose stations she may be
watching while I rotate towards ION.

I also have a Winegard AP-8780 preamp as well as the
Channel Master 7775. Is the Winegard less prone to overload
compared to the Channel Master ?

I took note of the overload issue you mentioned I might
get using the 7775

I have been very lucky to have pickup up 2 NOS Channel
Master rotators, " MADE in USA " models as well as the
3 NOS Radio Shack Hoverman's as well as two NOS
Winegard corner reflectors.

The corner reflectors don't look like the usual type with
the V shaped reflector but have a more rounded type shape
like this " C "
I have the original documents for these Winegard uhf
antennas, Model # U-620K

I have not found any reference to them online but I did email
Winegard to ask how I could interconnect the two if I wanted
to stack them & use a rotator & they said to use the piece of
300 twin lead that they cam with as this was for combining
them with a vhf antenna.

The driven element is a loop type with connections on the top
and bottom with instructions to attach the vhf antenna lead to
one set & the down lead to the other.

The directors also can be trimmed to improve channels 50 - 83
but as we now end at channel 51 it would not apply today.

I think these antennas were made in the 70's

Awesome score either way.

Thanks again for your time, I hope to meet in
person one day & you can come see my antenna farm. lol

Bruce.
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