Want to build..

PhotoGuyNJ · May 13, 2015

Want to build..Help Please

Hey Guys, I have this antenna, left behind by my wife`s uncle , its brand new, never used, dusty from being up in storage, he was an old timer, Old ham radio guy, wish I new, meet him before he passed several yrs ago.. any how I hope with all the knowledge here & help from you guys , & hoping I can use this, erect , get the rest of supplies I need .. put to good use.. Ok,, My fingers are crossed.. Thanks

n0nhp · May 13, 2015

That is a TV VHF High/Low FM Directional medium gain 300ohm antenna. Directionality towards the floor as photographed.
The boom and elements can be used various ways to make it an amateur antenna either in the VHF or UHF spectrum, however it is not currently set up as a transmitting antenna.

Bruce

PhotoGuyNJ · May 13, 2015

n0nhp said:
That is a TV VHF High/Low FM Directional medium gain 300ohm antenna. Directionality towards the floor as photographed.
The boom and elements can be used various ways to make it an amateur antenna either in the VHF or UHF spectrum, however it is not currently set up as a transmitting antenna.

Bruce

Thanks for the reply, maybe I should have asked if it is Possible , Could I use this for my scanners & what would I need to build/ hook up.. definitely put up outside on roof, out side my window on front dormer .. thanks

n0nhp · May 13, 2015

It would be directional for VHF, would work but probably have weird lobes for UHF and who knows how much 700/800...
If you can find one, a 300 Ohm to 75 Ohm transformer attached at the wing nuts running running to RG-6 coax would bring a signal in.
I guess the answer is yes it will receive some scanner frequencies. Will it do it well? No. It is designed to receive the old TV channels 2-13. It was never designed to receive the scanner frequencies except the VHF (121-172 MHz)
Any metal in the free air will work as an antenna. That is why those of us who like to play with antennas usually have many pieces of metal sticking up, hanging down, draped over and generally driving house mates bonkers.
If you can find the parts, give it a shot, if it doesn't help, cut it up and re-configure it.
I think the covers are about to fall off my ARRL antenna book and I have lots of spare aluminum in various stages of antenna-hood in many places about the property.
Good luck

Bruce

teufler · May 13, 2015

transformers are available on amazon, $4.92 .Amazon.com: 75 to 300 Ohm UHF/VHF Matching Transformer: Electronics

byndhlptom · May 14, 2015

want to build...

"Directionality towards the floor as photographed"

all the literature I've seen indicates that log periodics are directional towards the small end, ie. the longest element is the back of the pattern.....

should be directional towards the ceiling as pictured

or am I just confused??

prcguy · May 14, 2015

It would be directional towards the ceiling or the small end. I say loose the TV antenna and get a scanner antenna of your choice.
prcguy

byndhlptom said:
"Directionality towards the floor as photographed"

all the literature I've seen indicates that log periodics are directional towards the small end, ie. the longest element is the back of the pattern.....

should be directional towards the ceiling as pictured

or am I just confused??

popnokick · May 14, 2015

A lot depends on what you listen to, what you expect this antenna to do, and your budget. What it probably will do very well if placed outside your window / dormer and turned to a vertical orientation (tips of the elements pointing to the sky and the ground) -
- Receive VHF high band and low band in a narrow beam width from primarily a single direction
- Be very inexpensive and fun to experiment with... all you need is the 300 to 75ohm TV transformer and 75 ohm RG6 coax and connector / adapter to go to your scanner.

What it's NOT going to do well (if at all) -
- Be used for transmitting
- Receive signals from all directions
- Receive in the 400 mHz and higher (700-800 mHz) UHF bands

So if your goal is inexpensive experimentation, going on the roof a couple of times to adjust position and direction, and learning without a specific need for a wide frequency range omnidirectional scanner antenna... you're in luck. If that's not your intent... get an antenna built for the scanning you want to do.

n0nhp · May 14, 2015

Sorry, I lost the long reflector/driven element in the first picture, may be time for new glasses ;-)

Bruce

K5MPH · May 14, 2015

That antenna is not for scanning its an tv antenna ..........

popnokick · May 14, 2015

TV antennas work surprisingly well for scanning, because the public service frequencies are almost always adjacent to TV broadcast bands. And in the case of the "new" 700 mHz band it was actually created from the TV broadcast frequencies that were reallocated by the FCC from the broadcasters in the move to HDTV a few years ago. So old TV antennas are perfectly suited to that band. HOWEVER, you'll want to reorient the TV antenna for vertical polarization, which means mounting it 90 degrees off the usual horizontal mount, i.e. with the antenna element ends pointing to the sky and the ground. Oh... and yes, scanners can work with 75 ohm coax (TV type RG6) just fine.
So TV antennas for scanning? Don't knock it 'til you've tried it. (Or go out and by a $100 or more Yagi made specifically for scanners.)

KI4WOY · May 14, 2015

Rework the elements you could use it for Satellite reception. of course a good broadcast ban also. height is also your key also. I have had elmers show me how to make these out of light pipe and all thread cut to specs

PhotoGuyNJ · May 15, 2015

WOW, GUYS... so much info my head is spinning..lol, I was actually thinking what, popnokick said.. mounting it the way he describes & move the top & bottom elements in a "X" pattern. As for the middle element, stay the way they are for now.. or cut & rebuild..? then use all stainless for rebuilding.
I also have a Tower very close to me( communication tower service) , it has a lot of Antennas sticking straight up.. like a Platform at the top , I will have to take a pick , then post, maybe with some luck ?..
My Thoughts are to gather some material , cable, connectors..Etc.. and before making the permanent mount try it out see what happens ,

Thanks for the help guys.. any more Ideas , please let me know

Question Guys,, When I am ready to mount my antenna up permanently , it will be to the outside of dormer, easy access for me, what size pipe ??
1inch ? Galvanized, I know grounded.. will use a rubber piece between pole & antenna .. was thinking at least a 10ft pole.. Thanks again..

popnokick · May 15, 2015

PhotoGuy- Not sure what you mean by "move the top & bottom elements in a "X" pattern". You don't need to modify the antenna at all to use it for scanning. I've included a pic that illustrates a "normal" TV antenna mounted to a mast, and the way to turn it vertically and mount it on a standoff arm attached to the mast for scanner use. This is because what you will listen to on your scanner is vertically polarized (TV is mostly horizontal or circular). And the higher the better for the mast, although going to more than one 10ft piece of mast may require guy lines.

PhotoGuyNJ · May 15, 2015

popnokick said:
PhotoGuy- Not sure what you mean by "move the top & bottom elements in a "X" pattern". You don't need to modify the antenna at all to use it for scanning. I've included a pic that illustrates a "normal" TV antenna mounted to a mast, and the way to turn it vertically and mount it on a standoff arm attached to the mast for scanner use. This is because what you will listen to on your scanner is vertically polarized (TV is mostly horizontal or circular). And the higher the better for the mast, although going to more than one 10ft piece of mast may require guy lines.

Hey popnokick, WOW.. awesome thanks for the drawing !! now I def. have to start gathering material..
can you please tell what size pipe, material you use connectors, etc.. Thanks so much..

I will be taking picks for future posting..

popnokick · May 16, 2015

TV mast is readily available at most hardware and home stores. The tough thing to find is going to be the standoff arm that holds the vertical antenna away from the mast. I'm not finding anything ready-made. But you could use PVC pipe as the arm and a PVC t-section slipped over the mast and held by pipe clamps. The horizontal PVC arm then allows the normal U-bolt mount of the antenna. Don't forget the 75 to 300 ohm TV transformer, RG6 cable, and an F-connector to whatever adapter to the coax port on your scanner.

jim202 · May 16, 2015

One piece of advice on mounting the mast and antenna. Do not use a chimney. It looks strong and inviting, but the mortar was not made to hold torsional loads and vibration. Only downward forces. Over time you will find cracks between the bricks and the chimney will become loose.

Once the cracks are there, you have a liability waiting to happen. High winds can topple the bricks above the cracks and damage the roof, hit the side of the house or even if someone was walking by when it fell.

Don't take my word for it, do some research on the subject and see what you come up with.

There are a number of companies that sell straps to go around chimneys for mounting an antenna mast. Stay away from such a mounting system.

Your better off getting a house side bracket and bolting it to your outside wall of the house. Then mounting the support mast for the antenna to the bracket.

PhotoGuyNJ · May 17, 2015

Thanks, I appricate the help..

popnokick said:
TV mast is readily available at most hardware and home stores. The tough thing to find is going to be the standoff arm that holds the vertical antenna away from the mast. I'm not finding anything ready-made. But you could use PVC pipe as the arm and a PVC t-section slipped over the mast and held by pipe clamps. The horizontal PVC arm then allows the normal U-bolt mount of the antenna. Don't forget the 75 to 300 ohm TV transformer, RG6 cable, and an F-connector to whatever adapter to the coax port on your scanner.

Hey popnokick, I really appreciate all your help, So I am guessing that I can mount a tee on the top of the mass,if I get all threaded pipe.?? is that possible.? is pvc that strong to withstand storms... So I will have to hunt the mast 1st then go from there..are there different size mast I may have to go 15ft..?

jim202 said:
One piece of advice on mounting the mast and antenna. Do not use a chimney. It looks strong and inviting, but the mortar was not made to hold torsional loads and vibration. Only downward forces. Over time you will find cracks between the bricks and the chimney will become loose.

Once the cracks are there, you have a liability waiting to happen. High winds can topple the bricks above the cracks and damage the roof, hit the side of the house or even if someone was walking by when it fell.

Don't take my word for it, do some research on the subject and see what you come up with.

There are a number of companies that sell straps to go around chimneys for mounting an antenna mast. Stay away from such a mounting system.

Your better off getting a house side bracket and bolting it to your outside wall of the house. Then mounting the support mast for the antenna to the bracket.

Jim thanks for the tip, yes I was looking at the chiminey, now I am glad someone spoke up..As for the side of my house, that would be Awesome, only I am not a climber & will not do heights.. I have a Tower staring right at me, guessing 1/4 mile.., south then a I have a few north.. futher, so in order for me not to be afraid & be able to work with it .. its gon`a be attached front dormer side of window..lots of wood frame there..

Thanks a lot GUYS.. this week will be happy hunting time, I am also buying the multi port, want to add a base .., I`m sure it will grow,

well time for a small shack..lol

popnokick · May 17, 2015

First, you need to know that most TV mast comes in 10 ft sections. Go into Lowes or Home Depot where this is going to be reasonably simple to do: Get a 10ft section of TV mast and carry it over to the PVC pipe section of the store. Find a PVC "T" that will be a slip fit / tight fit over the end of the TV mast. That is going to be the PVC "T" that supports your PVC standoff arm. No metal "T" or standoff, or threads. All PVC press-fitted to the end of the TV mast. If you can't get a tight press-fit that can be pounded on to the TV mast, then plan on using adjustable pipe clamps to hold the PVC T-section in place on the metal TV mast. Get another piece (about 18") of PVC that will fit into the base of the "T" to act as your standoff arm.

PhotoGuyNJ · May 20, 2015

popnokick said:
First, you need to know that most TV mast comes in 10 ft sections. Go into Lowes or Home Depot where this is going to be reasonably simple to do: Get a 10ft section of TV mast and carry it over to the PVC pipe section of the store. Find a PVC "T" that will be a slip fit / tight fit over the end of the TV mast. That is going to be the PVC "T" that supports your PVC standoff arm. No metal "T" or standoff, or threads. All PVC press-fitted to the end of the TV mast. If you can't get a tight press-fit that can be pounded on to the TV mast, then plan on using adjustable pipe clamps to hold the PVC T-section in place on the metal TV mast. Get another piece (about 18") of PVC that will fit into the base of the "T" to act as your standoff arm.

OK, happy hunting has been unhappy.. home depot near me does not carry the mast .. have not tried lowes yet.. that is next, although I am willing to say they do not have it either.. I did pick up a kit that has the tools to compress the fitting with the cable..

One thing I see on Amazon they have rg-6 cable lot cheaper(not cheap as material, quanity) 500 ft for a lot less$$$ , its a quad?? I am running late right now will get back with details..

Want to build..

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