TV antenna amplifier question

[Ken Krawford]

I'm evaluating a couple of TV antenna amplifiers.  The signal range on one is from 50 - 2200 MHz, the other is 5 - 900.  Practically speaking, is one of these better than the other?
Thanks.

[Ron Hill]

Ken : Why don't you get a Hinkley TV antenna.  Doesn't take any power and mine works great.  Wrote a article in the Mainsheet about installing it. 
Figured if it was good enough for a Hinkley that it would surly work on a Catalina!!   

[Ken Krawford]

Ron, at your suggestion several years ago I got the Hinkley antenna.  In my never ending quest for a better picture, I tried the Radio Shack antenna amplifier (the 50-2000 MHz one) .  It did seem to improve the reception but then saw the 5-900 MHz amplifier and wondered if it would be better.  I guess the real question is "What frequency does TV broadcast over?"

[Ken Juul]

Channel 2 is 57mhz, channel 13 is 213 mhz.  Channel  20 is 509mhz.  When you get above channel 14 multiply the channel # by 6 add 389 = Freq in mhz. The amp you have should help with all the freqs including UHF channels.  The 5-900 is targeting standard ch 2-13.

Question for both of you.  Does the Hinkley antenna have any circuitry with it?  Trying to understand how other than for the name than can charge $108 for what looks to be less than $20 in material.   

[waterdog]

To find broadcast frequencies try this:

http://www.arrl.org/tis/info/catv-ch.html


All the UHF and VHF channels fall below 900MHz.   Wider frequency response (up to 2000MHz) in and of itself will do nothing for you.   Your best picture will come from an antenna with higher gain.    If your signal still isn't strong enough going into your TV you may have low signal to noise ratio.   An amplifier will improve it, but amplifiers always add noise and distortion to the signal as well.  Good connectors and good cables will help.    If your picture problem is snow or grainy picture, you have a signal to noise problem - higher gain antenna or an amplifier will help.   If you end up with rolling diagonal bars or other impairments (distortion), you've overdone it with the amplifier and you need a lower gain amplifier.   Almost all of the consumer grade amplifiers do not provide sufficient specifications to tell if you are really getting a good one and the relationship between price and quality is pretty weak.    Try a few and see what works.


Steve Dolling

[Craig Illman]

Ken - Where do the HDTV broadcast frequencies fall? Is this whole discussion moot come 2/19/2009?

Craig

[monasail]

OK, my day job is corporate engineering manager for a group of 38 TV stations, so I know something about this.

The highest occupied TV channel is presently 69, topping out at 806 MHz.  Higher channels were "reclaimed" years ago for cell phone and other "wireless communications" purposes.

Effective 17 February 2009 (by legislation), the highest broadcast channel will be 51 (698 MHz top) and all will be digital.  Those TV stations with digital (including HDTV) channels above 51 must relocate into the "core" (2-51) channels at that time (I have 5 in this situation).  There are very few stations ending up on the lower VHF channels, 2-6 (none of mine, thankfully).

A preamplifier good to 2000 MHz (2GHz) might be advisable for cable sources, but that bandwidth is wasted (and arguably problematic, due to the potential for preamp-generated interference) for off-air reception.  A rating topping out at 900 MHz will be more than adequate for off-air reception, now and in the future.

[Ron Hill]

Ken : To answer your question, the materials for the Hinkley antenna might be as high as $50? 
You can probably duplicate the phenolic blocks with starboard, but I've never seen such a heavy duty transformer.  The tubing for the omni directional antenna is available, and can be bent to the length of one wave length.  I don't recall that exact length, but it's about a 46 inch circumference? (I've got the exact figures on the boat - if you want).
Guess inflation has set is - as I recall paying about $86!! It does work well!! 

[Ken Juul]

Thanks Ron,
Been talking with some antenna experts off line.  theoretically the antenna should work well for only 1 channel depending on the wavelength of the tube.  Either the transformer electrically compensates for this or some other type of electronic magic is taking place.   I was thinking perhaps the tubes were actually carriers for several wire antenna sections sized to capture a wide spread of channels. 

The DIY is gettting too hard, stick is coming out this weekend.  Guess i had better get one on order.