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Old 19-Jan-2012, 8:33 PM   #9
RenoPaul
Junior Member
 
Join Date: Jan 2012
Posts: 12
In response to both of your replies:

Far be it from me to debate technical specifications, but from what little I do understand, a 3 dB gain is roughly equivilent to doubling signal strenghth. With this in mind, consider the additional 50 feet of low cost Radio Shack RG59u (2 - 25' with a connector to join them), and according to http://www.net-comber.com/cable-loss.html I've already lost 1 - 3dB over the frequency range , probably more with 10 year old, cheap cable. So, with that I figure the gain is more like 6db or more. Without proper test equipment, I really have no idea of the actual gain. Again, this is without the use of any type of amplification.

However, as far as topology goes, my house is at 4800 feet, and less than 500 feet south of me, there is a hill that is almost 5000 feet. The transmitting tower for the VHF HI channels is close to 20 miles south of me, and direcly blocking line of site to the transmitter. Hence, the 2Edge Path in the chart.

My signal strength is solely based on the "Antenna Setup - Digital) on my Sharp SB57 Series TV. and I have no idea of the relation of their "0 - 100" scale vs. dB, and/or AGC on the receiver.

What I do know, is that the ClearStream 2 mounted outdoors 20 feet above ground level, was able to get the lowest frequency, real channel 8 (KOLO. KTVN - 13 and KRNV - 7 were totally non-existant), at a maximum signal strength of 15 to 17 (totally undetectable with a channel scan), and my home made cardboard mounted "leoda" based design, sitting in my living room (farthest north part of my house) with 50 feet of cheap RG59u brought my signal meter to 52. Also, take into consideration that my house is full of EMF producing equipment; Surround receiver, appliances, cordless phones, WIFI, Bluetooth and more than 7 computers running full time, all sitting between my test antenna and the southernmost part of my house.

To make matters worse, sitting in the high desert of Nevada, we are prone to many high level wind storms. Some close to hurricane wind speeds. This makes it extremely difficult to safely mount a large antenna on my roof, or a tower. In fact, today the general area is experiencing wind gusts of over 40 mph, and at my house, I've recorded gusts of almost 60 mph.

So, in layman's terms, as it seems most of antenna questions aren't coming from engineering or technician minded people, I must restate my situation and opinion. Granted, this is in my case, but the thread title clearly implies that.

For MY situation:

1. Every retailer claims that reception is slightly possible with the best deep fringe antenna available, preferably with a stacked configuration, in order to get the 2Edge VHF HI stations.

1a. All of the LOS stations, KAME, KNPB work without any antenna, KRXI worked with simple rabbit ears (non-amplified). When using the amplified antenna, I had to turn the amplifier off for KAME. KAME also works with just exposing the F connector.

2. Weather conditions prohibit a heavy antenna without a tremendous amount of support.

3. Commercially available compact indoor/outdoor amplified antennas don't work well.

4. The William Ruckman design works pretty good both indoors and outdoors without an amplifier.

5. The leoDA version of the William Ruckman design works very well indoors (outdoor tests will be made when weather permits)

With that in mind, I honestly think that most people that can read a ruler and protractor, can afford a few feet of copper wire, a box of thumbtacks, a piece of cardboard or foamboard, 2 screws, 2 clothespins, a bit of masking tape, and a matching transformer with a short piece of coax cable, can build a quick test antenna in less than an hour. Much less expensive and less time consuming than climbing their roof with a helper, to install a large antenna.

To make matters even easier, it seems that exact measurements aren't all that critical, although I did correct the scale of the template from William Ruckman's image to match my printer. That made the need of using a ruler and protractor minimal.

Yes, I know that the techies will debate this point, but for a person to use either of these designs to see if a particular channel might work before spending a good chunk of cash on a quality commercial antenna...

A note on Dave's comment regarding "gross negligence":

My main concern was for the 3 channels in the VHF HI band, KRNV, KTVN and KOLO. And, taking into consideration of the frequent high wind conditions, the close proximity of the hill south of my house. Also, I aimed my test antenna for the best reception for KTVN, so the KAME signal level is not at its optimum.

BTW, when I purchased my home, the Antennacraft HBU33 was already mounted to the side of the house, and had zero signal for KOLO, KRNV and KTVN. Of course, there was already damage to the eaves, and the guy wire anchors in the roof that cost more to repair than the antenna was worth. It was only mounted on a 5 foot mast.

So, again in my situation, the leoDA's modification of the Ruckman design (despite any possible VSWR mismatch causing loss of gain) allowed me to receive the 3 channels that a commercial antenna couldn't.

And a side note regarding high winds at my location. The previous owner of my home told me that 3 years before I bought my home a wind storm had blown 1/3 of the roof off my house. Its very common to have wind gusts well over 100 Mph at my location.

In my case, a Magic Bullet!

Out of curiosity, how do the ClearStream 2 and the Radio Shack amplified rabbit ear antenna rate on VSWR? And, is there an inexpensive way to actually test my system's VSWR? I do remember the old CB radio days using an SWR meter to adjust for transmitting, but never saw much difference in reception with a CB antenna that was "out of tune".

A note on Dave's comment regarding my situation is not typical:

I know that I'm not the only person in the world where a mid or full-size outside commercial antenna isn't feasible or possible. And I also don't believe there are any antenna installers that will refund their labor charges if a commercial antenna doesn't work. I'd rather throw away a $10 experiment than a $50 - $150 antenna plus labor, and the cost to repair holes in my roof or siding from mounting hardware. Therefore, I do believe my situation is more typical than you suggest.

Again, I must stress that the LOS stations, less than 2 miles away, are no problem. Only the 2Edge stations that are roughly 20 miles and the geographic obstructions.

A cheap set of rabbit ears and a $10 A-B switch will easily eliminate any problems from over-driving my receiver for KAME.

The technical aspects can be debated for years, but so far, I've only spent $8.00 and have a working antenna that is capable of delivering the stations I want, and its still sitting indoors, without an amplifier.
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