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Old 24-Apr-2015, 2:46 PM   #21
sl1982
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I purchased the db8e. It is sitting somewhat underneath my back tree. It doesnt have leaves on it yet so it is not affecting things quite as much as it will. I do have a spot on my roof that seems like it will have a pretty good clear view to detroit. As for the suburban aspect I am right on the south end of my town with not much in the way behind me. No more houses just a few commercial buildings and a refinery a mile or two away.
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Old 26-Apr-2015, 12:28 AM   #22
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Ok so i managed to get this thing up without killing myself. Good news is where i placed it it has a clear view beyond my neighbours tree. Right now it is just the antenna with about 30 feet of rg6-quad hooked up to it.

Pictures

Picture 1

Picture 2

Channels I get (just showing the main channel):

4.1 - 100%
7.1 - 75%
20.1 - 80%
28.1 - 50%
29.1 - 60%
31.1 - 60%
38.1 - 80%
50.1 - 40%
51.1 - 85%
56.1 - 75%
62.1 - 75%

To be honest I wasnt expecting to get so many of these. According to the tvfool report some of these should be almost impossible. Anyways I had a couple of questions. The antenna bobs around a bit in the wind. Should I be putting guy wires on it? Also can anyone see any issues with my mounting method? And thirdly I am planning on connecting the antenna to the outside rg6 i had run for the satellite. I would estimate the total rg6-quad at about 70 - 100 feet. Is an amplifier needed for this length?

Thanks for all the help guys. I really appreciate all the information i have gotten so far.

Oh and does anyone think i can pull in fox if i add a c5?
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Old 13-May-2015, 6:50 PM   #23
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Hey guys i am planning on adding a c5 and a juice preamp. Where does the amp for the preamp go? Before the combiner?

Eg.
Antennas
Combiner
Amp
Power inserter
Tv
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Old 13-May-2015, 7:36 PM   #24
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It depends on whether you want to amplify just the VHF signals from the C5 or both the UHF signals from the DB8e and the VHF signals from the C5.

To amplify both, mount the preamp after the combiner.

To amplify just the VHF, mount the preamp between the C5 and the combiner. In this case you would have to make sure your combiner passes DC voltage on the VHF side so that the DC voltage from the power inserter is able to get to the preamp.
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Old 13-May-2015, 8:15 PM   #25
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Quote:
Originally Posted by sl1982 View Post
The antenna bobs around a bit in the wind. Should I be putting guy wires on it? Also can anyone see any issues with my mounting method?
I would either lower the antenna or attach guy wires. That is too much height without some kind of support.
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Old 13-May-2015, 8:42 PM   #26
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Quote:
mount the preamp between the C5 and the combiner.
Won't work, the provided combiner doesn't pass power out the VHF port.

Combine, then amplify both.

Here's the basic diagram: https://www.antennasdirect.com/cmss_...e_Antennas.pdf
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Old 13-May-2015, 9:22 PM   #27
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Ok and where would i put an FM Trap? Between the antenna and the the combiner?
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Old 13-May-2015, 10:56 PM   #28
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Install the filter between the U/V combiner and the input of the preamp.
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Old 14-May-2015, 1:06 AM   #29
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Quote:
Originally Posted by ADTech View Post
Won't work, the provided combiner doesn't pass power out the VHF port.
The Pico Macom and the Blonder-Tonque UVSJ combiners pass DC on the VHF side if that feature should be needed in an installation.
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Old 6-Jun-2015, 1:05 PM   #30
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Hey guys,

Had someone knock over my antenna while it was sitting in my backyard and it did some damage to it.

One of the bowties is broken off entirely and the other one is loose. Here are some pictures.

Broken bowtie

Loose bowtie

Is the antenna toast at this point? Or is it repairable? Should I just put it up and see how it performs?

Thanks for the help
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Old 6-Jun-2015, 5:47 PM   #31
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Call in Monday between 9-5 Central and ask for Melissa. She should be able to find you what you need.

We often scrap out antennas that are not resellable but we do keep some of the parts on hand.
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Old 15-Jun-2015, 3:30 AM   #32
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I managed to fix it (i hope). I used a vice to compess the pins holding the loose ones so they were tight and epoxied the boken one back on. Hopefully it works good
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Old 30-Aug-2015, 1:38 PM   #33
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Hi guys.
I just got my c5 and got it installed. I was having issues with picking up fox vhf channel 7). I found a local antenna shop and they suggested getting a preamp. Got it installed and all working. The problem is the signal quality on that channel is only around 50% and it cuts in and out. Any ideas? The preamp has a fm trap built in and it doesnt seem to make any difference having it on or off.



On another note, channel 45 which is in the same area as channel 7 comes in at 98% signal quality.
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Old 30-Aug-2015, 5:49 PM   #34
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The link to your image doesn't work.

Quote:
I found a local antenna shop and they suggested getting a preamp.
What preamp did you get?

Quote:
On another note, channel 45 which is in the same area as channel 7 comes in at 98% signal quality.
WDIV NBC is on real channel 45 which comes in on the DB8E; WJBK Fox on real channel 7 comes in on the C5.

How is your system hooked up; what is connected to what?

Quote:
The problem is the signal quality on that channel is only around 50% and it cuts in and out.
What are you using to measure signal quality, the HDHR for Signal Quality (SNR) and Symbol Quality (Inverse of Errors)?
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Last edited by rabbit73; 30-Aug-2015 at 6:44 PM.
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Old 30-Aug-2015, 7:23 PM   #35
sl1982
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Sorry, here is a link to the picture.

https://onedrive.live.com/redir?resi...nt=photo%2cjpg

DB8e + C5 to combiner then to amplifier

I am using the HDHR for signal readings.

edit: The preamp is an antennacraft 10G212

Last edited by sl1982; 30-Aug-2015 at 7:25 PM.
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Old 30-Aug-2015, 9:30 PM   #36
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A 30 dB preamp probably isn't a good idea when you have several FM stations within 10 miles of you, two of which are 50 kW stations. See if you can swap the amp for one of the 15-20 dB models.
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Old 30-Aug-2015, 9:35 PM   #37
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Well it is adjustable from 18 - 30. I could turn it all the way down maybe? The place i bought it from doesnt accept returns unless its broken. Could another fm trap help maybe?
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Old 31-Aug-2015, 7:27 PM   #38
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If you click on the pending button in your report you will see that you have not 2 but 3 local strong channels; CHCH on real channel 29 from London has been added.

ADTech suggested that you order the Juice preamp because he thought it would tolerate your strong local signals while providing amplification for the much weaker Detroit signals if you amplified UHF and VHF signals. As you found out the Juice is backordered because of a manufacturing parts shortage.

If you want to amplify just the C5 VHF signals and let the DB8E provide the extra gain for the UHF signals, you would need to use a UHF/VHF combiner AKA UVSJ, that would pass power to the VHF only amp. The AD combiner can't do that, but there are UVSJs that will as pointed out by Tim in post #29.

There is a test that you can do now to see if your preamp can receive Fox on real channel 7 if it is protected from the strong local UHF signals from Oil Springs and London.

I suggest you try just the C5 connected to the VHF input of the combiner with the DB8E not connected to the combiner.

C5 > combiner > preamp > coax > power inserter > tuner

You can also add an FM filter between the combiner and the input of the preamp if you think the FM filter in the preamp isn't enough to attenuate your strong local FM signals. See attachment for an FM report based on my estimate of your location. You can do your own report using your exact address to see how close I came (southern edge of Sherwood Village):
http://www.fmfool.com/index.php?opti...pper&Itemid=29

How does the DB8E do on the Detroit signals (Not including Fox) without the amp? Are you satisfied with the results?
Attached Images
File Type: jpg sl1982TVF FM est2.JPG (116.0 KB, 401 views)
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Last edited by rabbit73; 1-Sep-2015 at 11:54 PM.
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Old 31-Aug-2015, 7:42 PM   #39
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Ok i will test that out. London is on the back side of the antenna and I dont even pick it up. The one from Oil springs i do pick up but not with 100% signal quality as it is pretty off axis from where I have the antennas pointed. I would prefer to keep the db8e amplified as it does help a few problematic channels come in reliably. If i remember correctly i did have only the c5 hooked up at one points just to the amp but not though the combiner. Does that make a difference?
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Old 31-Aug-2015, 7:55 PM   #40
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Quote:
Does that make a difference?
Yes it does because the combiner protects the preamp from the strong UHF signals in the test that I suggested. The VHF input passes VHF signals but rejects UHF signals. The UHF input passes UHF signals and rejects VHF signals. Look at the UVSJ specs here:
http://www.hollandelectronics.com/ca...-Diplexers.pdf

Quote:
I would prefer to keep the db8e amplified as it does help a few problematic channels come in reliably.
That would be a balancing act to provide a little more gain for UHF without overloading the preamp which would harm the reception of your weak signals. It has to do with the Dynamic Range which is the difference between your strongest signals and your weakest desired signals. When the preamp is overloaded by strong signals it produces spurious signals from IMD (Intermodulation Distortion) within the preamp that wipe out your weakest desired signals.



There is a limit to the Dynamic Range that your system can handle. When the Dynamic Range is too great you must resort to exotic (expensive) measures like custom filters and separate antennas for problem channels.

There is a technique that I use when without a preamp doesn't give enough gain and with a preamp gives too much gain. It is to insert an attenuator between the antenna and the input of the preamp to find the happy medium.
Attached Images
File Type: jpg SFDRdiagramJ3.jpg (103.6 KB, 854 views)
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Last edited by rabbit73; 2-Sep-2015 at 12:01 AM.
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