Antenna identification

[pablo2525]

Hi,

I am attempting to boost my cell phone reception at my cabin. I have a Yagi that works so-so. I believe the main issue is the signal is very marginal where the cabin is located. Up the hill, it'd be ideal.

I came across a honk'n antenna that I'd like to see if I can use. The first thing I am seeking help with is identification. Once identified, I might be able to do some research on whether I can make some adjustments to it in order to get it to work in the 850MHz range.

Here are some additional details on the antenna:

o Length of.pole: 18 ft. 9 in.
o Length between cross bars: 50 7/8 in. inside.
o Length of cross bars: 37.25 in
o Length of "rounded rectangles" at ends of cross bars: 34 in.
o Width of rounded rectangles: 3 7/8 in. inside, 4 3/8 in. outside.
o Width of cross bars: 1 3/8 in.

Thank you for your time!

-pablo

ps: the picture with the dog-body, he's okay. He was just sniffing around (Border Collie!) and when my wife took the picture, his head got cropped.

 

[n5ims]

It appears to be a 4 element folded dipole antenna array for the VHF-Hi band (140 - 160 MHz area). You appear to be missing a very critical piece, the phasing harness. This part has some critical specs (frequency dependent lengths and differing coax types to name two) that if you get them wrong you could end up with the elements working against each other instead of working together.

The amount of modifications necessary for it to work on the cell bands would be greater than what it would take to make a proper one from scratch. Think taking a semi truck and modifying it to make a sports car.

 

[pablo2525]

Thank you! Your analogy is perfect for my non-radio brain.

Cheers,
-pablo

 

[mass-man]

+1 to the previous comments....

On the other hand, if you want FM radio reception at the cabin, you are in luck!!!!!

 

[pablo2525]

+1 to the previous comments....

On the other hand, if you want FM radio reception at the cabin, you are in luck!!!!!

My *gawd*!!! My wife and I are having such a laugh on these comments!

Of course, in hindsight, we shouldn't have brought that sucker all the way up to the cabin. There is no road access so I had to set it diagonal across the gunnels on our vintage late 1960's boat. It came with the cabin.

btw, the cable it came with is quite awesome. It's like 1.25" thick ... super shielded. I'm sure it's worth a bundle.

Cheers,
-pablo

 

[nd5y]

It looks like a Sinclair antenna. On some of those the phasing harness is inside the mast and elements. One end of the mast should have a cable coming out unless somebody removed it. It appears to be for VHF high band so it would be useless for cellular.

 

[doublescan]

Amazing. I didn't know there was VHF antennas THAT big. He could get FM from Australia!

 

[W8RMH]

What you need is a cellphone booster.

Wilson Cell Signal Repeaters for Home and Office

 

[pablo2525]

Hi,

I have a Wilson but the signal is marginal. I believe either positioning my Yagi higher or a higher gain Yagi.

Thank you everyone for your replies ... back to the drawing board.

Cheers,
-pablo

 

[N3LLO]

Looks like it might be an equivalent to one of these Broadband Dipole Antennas - FM Transmitters, LPFM Transmitters, & FM Radio Broadcast Equipment

 

[nd5y]

I need to correct myself. It is probably a Comprod 874F-70
Antennas - VHF Exposed Dipoles - 870 Series (138-174 MHz) | Exposed Dipole Antennas | COMPROD Communication

 

[milkman21218]

Look at the Wilson Trucker cell phone antenna. The long tall one it may help.

 

[902]

Don't go too far down that road, because it's the wrong road for what you are looking to do. That's a VHF antenna and will do a cellphone absolutely no good unless the elements are unbolted and the 20 foot section is used only to support a yagi.

Your place sounds a lot like my house in the Midwest. Not a lot of cellular coverage and I would fall off the face of the earth in terms of coverage once I came around the corner on the main road and started to drive up the driveway.

These are a couple of things I might do. I actually did the first one and it worked well enough for me. Not spectacular, but better than without. I did the second one at work, but had things to measure the results and carefully set levels.

First idea -
Get a high gain yagi, some 1/2" LDF cable, and a high gain omnidirectional antenna.

Step 1, put the yagi up as high as possible and as far away as possible (within reason) from where you intend to use the cellphone inside the house. I'm talking more vertical separation than horizontal.

Step 2, run the 1/2" cable into the house and put lightning suppression on it as appropriate.

Step 3, terminate the end of the cable with the omnidirectional antenna, which could be mounted inside a wall between studs.

What you just made is a passive antenna system that collects RF outside, channels it inside, and radiates it through the omnidirectional antenna. In theory, if you drive the antenna outside with enough signal level, it will propagate through the cable and out the other antenna for a net gain over what you would have without any of it.

Second idea -
You could use a bidirectional amplifier, but you would need to make sure you have adequate isolation between the inside and outside antennas. If not, your device could break into oscillation and potentially harm a variety of communications systems. In short, if you don't have the instrumentation to measure your isolation (a spectrum analyzer and high-level tracking generator), and devices to adjust gain through either software or padding down inputs and outputs, you shouldn't mess with BDAs - especially in a free-space environment.

 

[n5ims]

Depending on what services you have available in your cabin (broadband internet specifically must be available) your best choice would probably be one of those fematocell units available from your cell phone provider. It would be fully legal, supported, and provide you with great signal where little or none existed previously. Basically they're a micro cell phone tower you can put into areas where you need service. The units generally need GPS signal (to activate them so they can't be taken overseas) and an internet connection (for communication between the unit and the cell phone company itself).

Here is one for the Sprint network --> Sprint AIRAVE Wireless In-Home Signal Booster for Voice & Data

Often they're available for sale from the cell phone companies for $100 - 150 or so. Don't stop reading just yet though since there's another way to get one for much less. If you're a customer in good standing with the cell company (and under contract) you can often get them to send you one for free (or a nominal charge) if you call their customer service number and demonstrate just how poor the coverage is where you need it. You can't have the call about getting one of the devices (I never mentioned it until the rep brought it up as a solution), or they'll simply insist you buy one if you want one. The call must be about how you can't use your phone in your house and must go outside (to a second story, etc.) to make a call. Only then do you have a shot for qualifying for a free (or heavily discounted) one.

 

[krokus]

I have a Wilson but the signal is marginal. I believe either positioning my Yagi higher or a higher gain Yagi.

Do you have the correct version for your carrier? How do you have the external antenna hooked up?

 

[SCPD]

cell boosters

Sorry to hear the Wilson isn't working for you.
We have been using zBoost model SOHO YX545 and are very happy with the results.
It comes with 50' of thin line coax, with f-connectors on both ends.
You can replace the supplied coax with up to 150' of low loss RG59 coax.

But, like the Wilson, you need a decent signal at the outside antenna.
They do sell directional antennas, which we have never used.