VU-190 XR Antenna

[FreQi]

With the strangeness I have been running into with OTA DTV signals dropping out, I am considering buying a new, larger antenna.  A friend of mine suggested I get the VU-190 XR from Radio Shack, and when I found out it's a $100 antenna on sale for $50, and the Brookfield Square shack has 3 of them... I figured it sounds like a good deal.  But I'd like to prod you guys for advice before I rush in and buy something that won't help.

AntennaWeb.org says I need a "yellow" antenna, which is a Small Multidirectional Antenna.  This VU-190 seems more like it would be considered "large" and "directional".  Here are a list of the stations (I care about) and their compass orientation from my address.  Any opinions on whether or not I should get this one?

WCGV-DT 25 UPN 72°
WTMJ-DT 28 NBC 74°
WITI-DT 33 FOX 29°
WISN-DT 34 ABC 60°
WDJT-DT 46 CBS 60°
WVTV-DT 61 tWB 72°

As a comparison, here is a photo of my current antenna.  It's about 4 or 5 feet long and was rescued from my fathers garage, so I don't know much of anything about it.  Until 2 days ago, I was getting low 80's for signal strength on CBS and ABC.  Now those stations are bouncing between 78 and 82, and then drops to 0 every couple minuets.

[Greg Oman]

I don't know that the sudden drops are really antenna related unless it's moving around a lot on the mast.  If you haven't checked the the connection to the antenna, I'd start there.  Make sure all of the elements are still firmly attached.  Then, look at the balun (converts the 2 wires to coax), and finally, follow the wire back to the set, inspecting for cuts or sharp bends that could be causing the coax to fail.  Check all of the connectors also-- they all should be firmly attached.  If doing this is too hard, simply string a temporary new run of coax to the set through a door or window, and see how the signals compare.  If the new is much better, it's probably more of a line problem than the actual antenna.

How long is the cable run?  Do you have any devices inline of this antenna run (splitter, amp, etc.)?

I would say that the VU-190 may be overkill, I also have one and replaced it with a CM4228 as that worked as well, and is much smaller.  I'm about 20 miles from the towers and have no problems.  On most days, I get most of the Madison stations if I point that direction.

RS puts that antenna on sale a lot, so I wouldn't be too concerned about missing out on the deal-- spend a bit more time troubleshooting this behavior.

Greg O.

[mhz40]

The antenna you are looking at is actually very directional (a plus) and may be overkill in terms of gain.  I'd stick with what you have and invest in a rotor to try to 'tweak out' as much multipath as you can (read: ghosting on analog UHF channels) first.  Granted, this could prove difficult, if not impossible.  Good luck!

PS: Take a close look at the antennal grounding...  By the looks of things, you've got a great lightning rod there.

[FreQi]

I did end up getting this antenna, and got it installed a few days ago.  It increased my signal strength by only a few points, but I am not experiencing the signal drop-outs anymore.  Of course there are several things that could attribute to that, such as the change in weather, re-positioning/aiming of the antenna, etc.

The antenna could be wobbling around in the wind, as the mast is pretty long, and the antenna is rather large (now).  Perhaps I should install some cables to stabilize the thing.  Just a few more holes in the roof my landlord would love.

As for checking the cable for damage, I don't expect that to be the problem as I have only had it up for a month or so, and it was brand-new HDTV grade coax.  The cable is -very- long, so I am not too keen on the idea of a temporary replacement.  It reaches from the middle of a 2-story roof top, down the side of the house, into the basement, and then through the ceiling and walls of 2 rooms down there.  So I'd guess it's at least 40 feet long, although I never actually measured it.

The balun (as you called it) is brand new and seems to be in working order, with the weather boot and everything.  There is however one section of the coax that is rather tightly coiled.  Probably 4 inches in diameter and wraps 4 or 5 times.  Maybe I should straighten that out, but would it really make a difference?

And about a ground... How should I set that up?  I understand I have to pound an 8 foot spike into the dirt and run a thick wire to the antenna, but should I just fix the cable to the stand, or to the antenna itself, or to the mast, or...?

[Gregg Lengling]

Originally posted by FreQi


The balun (as you called it) is brand new and seems to be in working order, with the weather boot and everything.  There is however one section of the coax that is rather tightly coiled.  Probably 4 inches in diameter and wraps 4 or 5 times.  Maybe I should straighten that out, but would it really make a difference?


No not really, actually it makes a trap for surges.

And about a ground... How should I set that up?  I understand I have to pound an 8 foot spike into the dirt and run a thick wire to the antenna, but should I just fix the cable to the stand, or to the antenna itself, or to the mast, or...? [/B]

A ground to the antenna system, IE;  Supporting tripod/mast is required by National Electric Code.  You need to the run the ground wire (minimum 12 guage) from the ground rod to the Tripod or mast you are using.  I would also get a lightning ground adaptor for your coaxial cable (you can get them almost anyway...just a blockly looking object with 2 female "F" connectors, and also attach this to the ground cable just before you enter your house with the cable.


Just a note....should you have a nearby lightning strike and have damage to your system and haven't installed the ground wire...the insurance company could legally void the claim.  Although this usually never happens because they usually don't investigate that far......(my brother-in-law is a retired VP for a very big Insurance company).

Good luck and play it safe....do the grounding properly.

[ugyvel]

Gregg--regarding grounding--the satellite instructions say that your grounding wire should run straight down to the grounding rod.  How important is this?  My dish is off of an upstairs deck and to reach the grounding rod (actually a water pipe to an outdoor spigot, it has to travel sideways about 15 feet to get to the side of the house above the pipe.  Any thoughts?

[Gregg Lengling]

They just want you to run as direct as possible to the ground system without any very sharp turns.  Lightning is a very high frequency pulse and it will see a sharp turn as an inductor and won't follow it.  I guess a lot of people use water pipes but according to NEC (national electric code) this is not a legal ground...you must run a ground rod into the ground.