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

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6 Responses to “Building a Gray Hoverman GH10n3 Antenna For UHF & VHF Band III TV Reception”

  1. raymond Says:

    hi

    i find your gray-hoverman antenna DIY article very interesting, however can i know where to buy the important piece of 300-75ohms balun?

    • asahjaya Says:

      I got it from local electronic shop. Its the one that have two connecting terminals for the 300 Ohm flat cable on one end and the other end a connector to the TV. It is usually black in colour and rectangaular in shape about 35mm in length with the numbers 75-300 emblazon on it. Probably you have seen it before. I removed the transformer from the casing then attached it to the rf cable and to the feed point of the antenna plus wrapping it all in black tape, the balun and the soldered connections that is. About the balun, you can check it out here, http://antiqueradios.com/forums/viewtopic.php?f=2&t=171510&start=40

      If you can buy one online (the one in the last picture in the link given above) then it should save you the trouble.

  2. james Says:

    the result?

    • asahjaya Says:

      I am happy with it. I can receive all the VHF channels from Singapore clearly except for channel 12, fair but a little grainy UHF from Singapore and Indonesia but two UHF channels from Indonesia are clear. I guess it depends on the signal strength. All the local UHF channels plus one VHF channel (10) are very clear indeed.

      These are all analog transmissions.

  3. Max Says:

    Thanks for the details on the GH10. I have the most of the materials and plan to build one soon. I will be using #6 copper for the driven. The rough sketches help. Nikimls graphs are super detailed and the simple notes you drew seem much easier for me to grasp. Eventually, I am considing building a quad, but will attempt one first. I live in a remote area with the closest station 60+miles away through foliage. I have build variations of the DB4 and DB8, but always come back to the hoverman. My goal was to determine what works best for my area. I can distance the morning news until about 8 am. I have just mounted my attempts on a pole on my deck for each experiment. Now that I have decided on the GH10 and intend to build it to last and attach it to my chimney with a rotary motor since I am centered about in the middle of nowhere. The stations I am interested in are in 4 separate directions. Thanks again.


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