Our prices reflect the cost of import - security inspections, customs
duty, and freight, as well as our service before and after the sale.
We
try to be in the office on Tuesdays from 10-6 PST to take your calls.
206-323-8845 Email us any time and and we'll reply as soon as we can.
Even if you are new to digital television and/or DXing, we'll spend
time with you to help understand your situation.
Shipments go out on Tuesday and Thursday.
We will work in the rain, in the dark, and in the wind, but only one at a time!
USAV - OFF AIR FAQ (We'll publish an entirely expanded & updated FAQ as an Antenna Voodoo e-book in June 2010. Your suggestions, comments, and requests are welcome)
This information is provided as a service to other professionals, hobbyists, and potential customers. We're always happy to talk antennas with folks. However, if you disagree, don't flame us. There are plenty of "experts" on the forums that are glad to argue with you or beat their favorite theory to death. We are more interested in helping you to get results.
What does help receive particular terrestrial stations?
Antenna selection and placement remain the most important aspects of
reception. There is no substitute for an organized signal and the clean gain of big metal. Join-tennas and other filters, stacking, attenuators, phasing, mixers, etc. may help later. But, finding the sweetspots at your location is your first concern.
Do I need a spectrum analyzer?
No. If you can, do a site survey with a patient and motivated friend or family member who can tell you a stream of signal levels and take notes for you. If you are serious about getting over a threshold, take notes in a spreadsheet to keep track of every variable, and you’ll get your best chance at good reception.
How do I visualize my RF environment?
Start by thinking of ribbon candy that is coming toward you from the transmitter towers. As those ribbons interact, patterns will occur. Those flower-shaped patterns will probably repeat (to a certain degree) in even increments. Say you have a tower due West of your location. As you move from South to North, the signal will alternately increase and decrease. (Think of moving slightly at a stoplight and the FM changes, same thing, because FM is in the middle of the VHF band.) If you are careful, you can determine the distance. Imagine studs in a wall that repeat on 16" centers, your signal for that station may repeat on 18' centers, for example. Next you'll need to find sweetspots where all the signals you want converge. It may take more than one antenna. And some real effort.
What do I need?
At least a 50 or 100 foot piece of coax. Good wire and connectors do work better than cheap ones. Get a hand held or portable TV with a whip antenna or a plug or terminals for attaching an antenna. They're cheap at pawn shops. A signal strength meter always helps, but analog strength levels don't correspond directly to digital ones. Start by walking the whole area with the little TV and learn about your RF environment. Hook up your antennas to first the portable, and then to your HD receiver. Use cell phones, walkie talkies, baby monitors, friends, whatever... to use the audio feedback from the meter in your receiver as a guide. You may find that your receiver card is more sensitive than your satellite DVR’s off-air tuner, or maybe the one that came in your TV is your best one. The tuner in a VCR may be more sensative than the one in your set, if you're after analog only. Find out. You may end up with a coat hanger on the back of your tv for getting some strong locals, but you use your set-top receiver and custom antenna rig for watching the difficult ones. If you see what I mean ...
Is a higher mount better than lower one?
Not necessarily. Don’t automatically stick it on the chimney!! Look for the sweet spots where you can get as many stations (that you want) as possible. DXer Jim Dickman sent me this good explanation of siting -------
With digital television in fringe settings, inches matter and degrees matter.
Can I install antennas in an attic?
Maybe. Can you get in there with an antenna or two and move around? Are there any sweetspots in there? What is the roofing material? Because attics are often nasty places and signals can be attenuated 7 to 12 dB right off the bat, it isn't easy. Please wear a mask because insulation dust, drywall dust, suspended-ceiling dust, and rodent/bird feces dust are all bad for you. Also, prepare for insects and extreme temperatures. Determine wiring paths and AC access, if necessary. From your site survey, guess where sweetspots might be. Stick your antenna(s) where you think they'll perform. Optimize the rig. Takes readings and notes. Now go outside and randomly drop the antenna on the ground, it'll probably outperform the attic - only half kidding. Unless you have room to swing a cat and you aren't too far from the towers, I wouldn't try an attic antenna setup. The only reasons to consider an attic are that you have a really flimsy antenna or you haven't figured out a good external mount. There are many ways to conceal or camoflage antennas, and Federal laws prohibit owners' associations and real estate covenants from interfering with someone's antennas in their own space. True.
Will I get best reception pointing directly at the tower?
Not necessarily. At USAV world headquarters, we get digital FOX reflected from the side of an apartment building at the top of a hill using a DAT 75. The tower is 18 or 20 degrees to the north of where the 75 is pointed. So work your area around the location, as well as on the roof and under the eaves, and on the walls. Signals do bend and bounce, sometimes reliably.
My reception is intermittent. What can I do?
Maybe nothing. If you are getting a bounce, a refraction, a seasonal or weather-related reception pattern, that may just be the breaks. Sometimes you can reduce interference or organize the multipath, but again, you may or may not get consistent performance. Fortunately, reception problems can often be solved by a combination of hard work, good observation, and serious design. The experienced antenna contractor has many options in their toolbox that can be recommended in specific situations. Preamps, filters, stacks, arrays, mixers, combiners, circuits, and gizmo boxes may be appropriate.
Televes DAT 75 vs. Blake, Channel Master, Winegard, and the "knockoff" models from LaCrosse, x91, 4228, 4248, 9095 etc. -
We find the gain figures on many "high gain" antennas to be approximately similar to a Televes DAT 75, but we rarely obtain additional stations with these models. With the Blake and the Televes, our crews get more stations. However, the Blake is way more subject to corrosion than even most US-made antennas, tends to bow over time, and is not very sturdy. So, at a similar price, why would you buy a Blake, when you can have a Televes? The DAT 75 is a 10-year plus antenna, even if you have icing, eagles, or high winds. The DAT 75 has the most options for mounting and pointing with two positionable cast alloy clamps. It accepts an integrated preamp. It's a honey!
Our Favorites At The Moment And Why
#1 Televes DAT 75 - All-Round Best For Money
#2 Blake - Performance=Good, Durability=Bad, Value=Poor
#3 4248 - Good value for the money in easy reception settings, not many mounting options
#4 Square Shooter w/o amp - Good for multiple mounting options
#5 4228, 4221 - Good for arrays to crank clean gain for multiple sets or long runs, flat mounting.
How are antennas different?
Design style, Materials, Size, Weight, Windage, Expected life
How good will my signal get?
Can't tell you.
There's one
location that got interference (pixelating) on terrestrial ABC at the
end of the 2nd Quarter during every Monday Night Football due to
airport traffic. Frustrating as it was, that was acceptable because
there was no HD alternative. There are other customers that would
prefer reliable standard def to HD that had any pixelation at all. What
I'm saying is that at the bleeding edge, there are different tolerance
levels.
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Amplifiers - Preamps, distribution amps, boosters
Amps can help you:
1) Stay above the reception threshold ie. reduce pixalation
2) Distribute the signal to multiple locations
3) Overcome signal loss due to cable length, splitters, filters, etc.
FM Reception
Terk & RCA Bar antennas make great FM bi-directional antennas. Saucers from Winegard and Antennacraft work well for omnidirectinal FM reception. For receiving distant transmissions (DX), you'll want larger VHF or FM cut antennas.
Splatter from proximate FM transmitters can be reduced with inline FM filters
ARE YOU LOOKING FOR:
a single UHF antenna?
a pair of UHF antennas pointed in different directions?
a pair of UHF antennas pointed in the same direction?
a single multiband VHF/FM/UHF combo antenna?
a separate VHF/FM plus a separate UHF, plus a separate AM antenna?
a separate AM antenna, plus a separate VHF Low, plus a separate directional FM, plus a separate VHF High, plus a separate UHF Low, and plus a separate UHF High?
or combinations of the above ...
Considerations when selecting antennas
Appropriate gain?
How many sets are you driving?
Can it organize a chaotic signal?
Is it sturdy enough?
Is it sufficiently directional or non-directional??
Is it in the sweet spot?
Attic or outdoors?
What investigative tools do you have:
Handheld TV?
Length of coax?
Ladders?
Antennas?
Tuner or receiver?
Digital tuner or receiver?
Signal meter?
Digital signal meter?
Spectrum analyzer?
FCC website?
Topographic info?
Antenna forums?
"Helpful" individuals?
What mounting resources do you have:
Non Penetrating Roof Mount (for flat roofs)?
Tripod?
Wall mount?
Pole?
Chimney Mount?
Extension Mast?
Guyed Mast?
Tower?
Things you need to know before you write or call
(particularly with HTPC cards and HR10250s)
What is the best way to assemble the Televes DAT 75 and the Televes DAT 45 Mix?
Custom Arrays
Secret Weapons
Fiber Optical
Training
Professional Equipment
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