Building a Gray Hoverman GH10n3 Antenna For UHF & VHF Band III TV Reception

SDIM0136

I left the standard single bay GH6 Gray Hoverman antenna at the rented house when I moved out to my new place.  Only recently that I had the time to construct an antenna again.  I had chosen the GH10n3 version of the Gray Hoverman.  The reasons were better gain and its dual band nature, UHF and VHF band III.  It is slightly more complex than the GH6 but still it can be approached simply and without any sophisticated tools.  The antenna is now up and running good except for a bit of double image.  This I assume caused by 3 segments of different RF cables being used though all are of 75 Ohm type.  One provided by the builder running from the living room to the roof.  Another, a short run that I did when constructing the antenna and because the cable by the builder is not long enough I had to add another segment.  So there are 3 cable segments and two joints from the antenna to the wall socket.  Apparently there are mismatches.  This I shall rectify after the Eid Festival.

That said, here are the pictures of the steps that I did in constructing the antenna.  Note that after the completion of the antenna, I decided to move the mounting from the rear stem to the main stem for the obvious reason, balance and stability.

A reference line drawn on the main stem

A reference line drawn on the main stem. The method for drawing I got it from the net

All the positions of the elements noted on the main stem and coded. Second line from top was a mistake

All the positions of the elements noted on the main stem and colour coded. Second line from top was a mistake

A tip I got from the net. The circumference of the tube measured with a strip of paper and then divided into four to get the quadrant marking

Another tip from the net, circumference of the tube measured with a strip of paper and then divided into four to get the quadrant markings

Holes drilled for the mounting of the driven elements and rear reflectors

Holes drilled for the mounting of the driven elements and rear reflectors

Obviously aligment needed here

Obviously alignment needed here

Tees for mounting the driven elements were extended

Tees for mounting the driven elements extended

A length of tube cut into strips

A length of tube cut into strips for attaching the reflectors by rivets

Reflectors and mount for the driven elements done

Reflectors and mounts for the driven elements done

Main stem insert with holder for driven elements and rear reflectors

Main stem inserted with mounts for driven elements and rear reflectors

During aligning process, holes were made bigger and even though bonded three or four pegs from satay bamboo skewers were driven to make the joint very firm

During aligning process, holes were made bigger and even though bonded with PVC solvent, three or four pegs from satay bamboo skewers were driven to make the joint firm

Job on the main stem done

The main stem done

Tees were used to hold the rear reflectors. Centering and holding the elements done with the use of rubber washers for water tap

Tees were used to hold the rear reflectors. Centering and holding the reflector element done with rubber washers for tap. Centre line marked on the reflector element and the hole on the T to see it

All the reflectors in place

All the reflectors in place.  PVC wiring conduit cover placed on the two sides

Driven element bended and strips of brass soldered with a portable torch

Driven element bended and strips of brass soldered with a portable torch

Holes drilled on the conduit covers on both sides and slots cut to slide in the narod. A piece of the other part of the wiring conduit cut and lock on with the cover to strengthen it

Holes were drilled on the conduit covers and slots cut to slide in the narod. A piece of the other part of the wiring conduit cut and lock on with the cover to strengthen it.  Two long and four short length of PVC wiring conduits hold the tips of the driven elements and narods in place

Grooves were made with a half round file before attaching the strips that hold the reflectors and screwed. Bonding solvent were then applied. The screws were removed after the strips had bonded with the stem except for the ones that attached to the stem of the driven elements holders

Grooves were made with a half round file before attaching the strips that hold the reflectors and screwed in place. Bonding solvent were then applied. The screws were removed after the strips had bonded with the stem except for two that attached to the stem of the driven elements holders

For anybody interested in constructing one, here are my sketches derived from the interactive 3D models on nikiml’s Antenna page.

Reflectors

Reflectors

Driven elements and Narods

Driven elements and Narods

Update 14 March 2014

Here is a map from Google Map.  My location is somewhere near the pointer.  Local transmissions are located at Gunung Pulai (Mt Pulai) which is nearby but the line of sight for the transmissions from Singapore (on the larger green area near Choa Chu Kang) and Pulau Batam, Indonesia (on the very western side of the island) is slightly blocked by the mountain.

location

Map by Google

Update 21 February 2016

I have made another antenna after this one and made used of Ts and I drilled through the Ts so that it just slotted through the main stem and held them in their places with the PVC cement.  Just recently I made another two using the method here and improved the method for aligning the mounts for the driven elements and Narod reflectors (the last three reflectors at the rear).  I drilled a few holes and inserted screws to hold them in place, then I applied fast setting resin adhesive at the joints.  Since resin is a very strong bonding material, it is very rigid and strong.

T

This one made using Ts

RFpanel

A 300-75 Ohms transformer inside the pipe connected to the RF panel connector seen here. Holes where screws were inserted to hold the radiator mount can be seen at the bottom of the joint

accomodate

The centre line of two reflectors are touching the pipe of two mounts so part of the holder for the reflector cut-off to accommodate and the corresponding pipe’s end filed. One of the lines seen at the bottom is a mistake, the other is the reference line for the reflector’s plane

Gray-Hoverman UHF Antenna

My rented house in Kulai (now Kulaijaya), Johor, Malaysia do not have an outdoor antenna. For local tv channels reception using indoor antenna, it is good since the transmitters are on a mountain nearby. I want to receive good analog tv signals from down south Singapore as well as from Riau, Indonesia which I estimated some 80 to 100 km away.

Since the ball had started rolling in constructing antennas (previously for my wireless client and the access point), I began to search for a good high gain UHF antenna. After a while, my attention was immediately focused on a little known, at least to me, Gray-Hoverman antenna. Interesting comments and feedbacks. What made me attracted to this design was the high gain plateau that covered most of the channels I’m interested in. Without much hesitant, I began on planning although I felt that this antenna was a bit on the hard side to construct.

Gray-Hoverman Dimensions

more details here.

Having had the diagram in hand, I figured about doing it my way based on those projects done by others. Once done, I laid down the plan. The reflectors would come from aluminium tubes salvaged from scrap antennas although some were of different diameters. Frame would be constructed from domestic pvc water piping tubes, T joints and tube holders. The radiator elements would be a 6mm diameter copper tube. I then listed down what were the items needed to be bought, the amount required and the length.

In constructing the antenna, first thing I did was the frame, then the reflectors, followed by cutting and bending the radiator elements. After attaching the radiator elements in place, I placed 4 short pieces and 2 long pieces of pvc plastic wiring conduit that had the sides cut off to hold them in place.

Here’s the rest of the construction pics at certain stages.

Update 13 Jan 2011

Actually I had a different idea for attaching the reflector elements, but I don’t have with me a tube that will fit in the reflectors nicely. What I had was a tube with internal diameter bigger than the external diameter of the reflector. So I cut it and riveted the reflectors to it. Also I did cut a small V groove on the flat side of the tube holder so that the reflectors will stay fixed and not to slide out.

Update 15 August 2013

I have constructed a GH10n3 Gray Hoverman which can be viewed here.

My First Serious Antenna Construction

I had done constructing antennas albeit in a makeshift way and the results were never satisfying. I was never serious about it until recently. I had an access point which was some fifty metres away at another house and I was getting weak signals. That was the turning point, I decided to build a good high gain antenna.

It goes without saying that the first step was to do a research. After all the searchings and readings, I set my mind on the biquad antenna. It was simple, easily construct and did not have many parts plus I had the parts readily available. Suffice to say that the construction was not exactly according to the specifications given that parts were practically from scraps.

The main radiator element came from the field coil winding of a car alternator. Aluminium plate encasing a pc floppy drive was flattened and used as reflector, and an RF(?) panel connector to connect them together.

After spending some times cutting, filing, drilling and bending, the result was as in picture #1. On the downside, I had to connect a RF to BNC female connector at the back of the antenna. Another potential loss, this was not good. I improved it further by constructing another design. This time the antenna was directly connected to the RG58 cable at one end and a female BNC at the other end while being encased inside a tube. I knew that the BNC was not up to par but it’s almost there and cheaper. Furthermore my situation was not that very critical that every improvement matters. I ended up making two antennas this way with slight variations.

There was improvement in signals but still there was interference. The transmitting and receiving angles of the biquad were quite broad. I wanted to narrow it down. In the end I ended up with a narrow, almost line of sight, high gain 21 elements yagi at both ends, the access point and my client.

In retrospect, signals are best amplified immediately after the antenna and not after the loss incurred by the cable. This means that I need to spend away with a usb dongle that can be attached to the client antenna almost immediately. Then, instead of RG58, I just need a longer usb cable. I will not be doing this on the access point side because of the cost involved and the hassle of putting up the access point router and POE device to power it plus the need to protect it from the weather.

Anyway, here are the pics.