Your wife dictates what the antenna should look like?

I thought the signal should dictate what the antenna looks like.

Yes, the coax between the preamp (near the antenna, I hope) and the power inserter should be one piece (except for the break for the grounding block) of high quality RG6 with a solid copper center conductor. I bought four different 100 FT lengths of coax and tested them for voltage drop:

http://www.highdefforum.com/1410658-post20.html

The 100ft Solid Signal Custom RG6 Quad with solid copper center conductor was the best.
http://www.solidsignal.com/pview.asp?p=sscblq

I then tested the coax for voltage drop and signal strength with increasing length, starting with worst 3 of 4:
http://www.highdefforum.com/1410662-post23.html

and:
http://www.highdefforum.com/1411096-post27.html

I didn't user the best SS Quad because I was trying to simulate a worst case for that OP, but it would have been the best.
I would consider 15 or 16 dB as a minimum.
Exactly what generic splitter did you use?
Maybe; try improving the coax first. Then try another splitter. Then, replace the passive splitter with a CM 3412 or 3414.

I noticed that problem with cable systems. The low channels would be weak, the higher UHF channels would be OK. The center conductor wasn't making good contact. The gap, as ADTech said, formed a capacitor that the UHF signals were better able to jump than the VHF signals (it's called capacative reactance, and is frequency dependent). It can also be caused by poor shield contact.

If you had that problem between the preamp and the power inserter, the preamp wouldn't get proper voltage, but it could happen after the power inserter.

I test F-81 adapters and other female connectors with a short length of bare copper wire to be sure it grabs the center conductor securely. Actually, I use a piece of copper clad steel center conductor from a short length of RG6 because it is more rigid, and file it to a point for easy insertion. I have found that some cheap F-81 adapters are really bad.

http://forum.tvfool.com/attachment.p...1&d=1501113484

http://forum.tvfool.com/attachment.p...1&d=1501113638

http://forum.tvfool.com/attachment.p...1&d=1501114030

http://forum.tvfool.com/attachment.p...1&d=1501114168

http://forum.tvfool.com/attachment.p...1&d=1501114294

Best pre-amp for long-distance run
 

So I have the opportunity to borrow a 70-foot boom-style man-lift to do some painting and roofing jobs around the house. While I have it, I figure I might as well put an antenna as high as I can in one of my tall pine trees. My TV fool report indicates about a 2.5 dB improvement in WFFF at 75 feet in the pine tree, vs. 30 feet AGL on my roof. I plan to vertically stack two HDB8Xs to get the most bang for my buck. With that stacked configuration, in the hottest hot spot on my roof, I have never been able to get better than 20% reception reliability for WFFF. I'm hoping I'll do better than that up in that pine tree.

My plan is to mount the two HDB8Xs onto a mast and then use conduit clamps to bolt the assembly to the tree. I will cut limbs as required to get a clear view to my Mt. Mansfield towers.

My question is in regards to pre-amp selection. From the antenna, down the tree, and into the house, this will be about a 300-foot run. I'm concerned about the voltage drop in terms of supplying power to the pre-amp. Is there a certain pre-amp that is well suited to such a long run?

Also, reliability is a major concern. It could be a long time (or never) before I have access to the lift again, so I also want a pre-amp with low odds of failure.

Finally, are there any mods I should make to the HDB8Xs to minimize chance of failure? I'm thinking mainly in terms of the baluns on this, but maybe there are other aspects I should be concerned with.

Thanks you guys.

Combining 2 antennas is hit or miss, sometimes it works as planned, sometimes it no different than one, sometimes it makes things worse. The sad part is, no way to predict which one you will get, you have to try it and see.

Also a vertical stack makes the vertical aiming very critical, as it makes a very narrow beam width in the vertical direction. You will need a method of adjusting the vertical angle in 1 degree increments to fine tune it.

I would take a small TV attached to a long extension cord up in the lift with you to use to fine tune your aiming. It's critical you get it right since you won't be able to get back up there again.

Mount the preamp down closer to the base of the tree so you can reach it if needed. The small sacrifice of noise figure is worth it. Same goes for tall towers. That was a lesson learned the hard way.

Micromanaging the elevation in the TVFool simulator, especially with 2-edge signals, is usually not a productive use of time. It's my hands-on observation that 2-edge signals, when actually measured, can differ from the calculated signal power by as much as 20 dB. The closer one the receiving antenna is located is to the last diffraction zone in the signal path, the wider the variance can be.

A vertical stack would be expected to cut the vertical beamwidth approximately in half, frequency dependent. Since a typical 4 or 8-bay antenna would be expected to have a vertical - 3dB BW in the 30-40° range, the vertical stack of two of them can be assumed to be in the 15-20°. Theoretically, that means there won't be a great deal of reception difference if the incoming signal path is within 7.5-10° of horizontal (assuming the mount is truly vertical). YMMV or, better yet, YAMWV (Your Actual Mileage Will vary).

If using a tree mount, stripping as many branches as you can will reduce sway in the wind (which you don't want). Try to balance the health of the tree, unless you want to sacrifice it to be a pole, with the need to reduce that swaying behavior.

I would expect that stacked antennas in a swaying tree would be counterproductive. The extra gain would help only on calm days. If the height helps, you may not need the extra stacking gain. If you want to try mounting the preamp lower on the tree, I'd suggest a run of RG-11 coax between the antenna and the preamp.

Running coax underground
 

Success! I mounted a DB8e and an MCM-30-2476 in the pine tree at 55-feet AGL and am now receiving all major networks from 70.5 miles (2-edge), even WFFF which is listed on my report to have an NM of about -5 dB. I combined the two antennas with an Antennas Direct UVSJ and confirmed signal strength over a few days at the end of the 50-ft RG-6 coax that leads to the base of the tree. Whereas my best roof-top hot spot only senses WFFF with an SNR=8 dB on average, my new tree-top arrangement is clearly receiving WFFF with an SNR of around 22 dB.

My last steps are the relatively simple tasks of amplification at the bottom of the down-lead at the base of the tree, and then running the coax from the base of the tree to the house. Per the requirements of my "domestic beautification committee", the coax must be routed underground.

I'm looking for any advice on trench depth, cable selection, conduit selection, etc. for completing this underground run of about 125 feet.

Thanks in advance!

Nice work on finding a hot spot for your signals.

There are two ways of running coax underground. RG6 in conduit, or direct burial coax without conduit.

With coax in conduit, there are two schools of thought. You can use water tight conduit or perforated conduit in a sand bed for drainage. When coax is run in water tight conduit, it will still be in a pool of water from natural condensation, hence the perforated conduit approach.

Keep in mind that you might have to pull a replacement length of coax in the future. Avoid sharp bends and hard pulls that can damage the coax inside.

http://forum.tvfool.com/attachment.p...0&d=1501114379

I haven't done it myself, so I suggest a Google research focusing on ham antennas on towers.

If you have a preamp at the base of the tree, then the preamp voltage will come from the power inserter inside. It will be necessary to take into consideration the voltage drop for the preamp. RG6 with a solid copper center conductor will have a lower voltage drop than coax with a copper clad steel center conductor. Since the DC current for the preamp also flows through the shield, quad shield coax has a lower resistance than dual shield coax.

Before digging a trench, lay the coax on the ground for a test to see the results.

A few updates...

I switched the downlead from RG-6 to RG-11 and gained about 1 dB on my worst channel (WFFF). I was surprised at how substantial that RG-11 coax is. I had to bore out the passthrough on the UVSJ enclosure to accommodate. I also switched to a continuous 150-ft length of RG-6 between the bottom of the tree and the house (instead of 100-ft of RG-6 coupled to a 50-ft of RG-59). I was pleasantly surprised to see that gain me about 2 more dB. Finally, I put in the very low noise pre-amp (KT-200, supposedly has only a 0.4 dB noise factor). I believe that gave me about 2dB more over my previous Channel Master CM-7778 pre-amp. So now I’m seeing an SNR of about 23-24 dB at the TV on WFFF. Threshold for reception is about 15 dB, so now I have some good margin. Atmospheric conditions can regularly steal 3-5 dB.

Next steps are to rent the ditch-witch and lay the coax and conduit, complete the grounding, and tidy-up the house-side distribution.

http://C:\Creare_Data\ZMisc\Pictures...s\DSCF6977.JPG

Thanks for the update telling us about the changes that improved the SNR of a weak marginal signal.

The link to your DSCF6977 image doesn't work.

Here are a few pictures. In the second photo, the branches look closer than they actually are. They are a good 15 or 20 feet away. I may do a bit more trimming before returning the man-lift, but it seems pretty clear when I'm actually up there.

http://forum.tvfool.com/attachment.p...1&d=1507303476

http://forum.tvfool.com/attachment.p...1&d=1507303487

Attachment 2928

Attachment 2929

Thanks for the photos. That lift looks ideal for the job.

Where is that building as related to the house, or is it part of the house?

http://forum.tvfool.com/attachment.p...1&d=1507315892

http://forum.tvfool.com/attachment.p...1&d=1507315892

That is my maple sugarhouse, which is part of my barn. The house is located about 100 feet off the left edge of the photo (130 feet between house and tree).

I buried the coax about 18" deep in a 1" black water-pipe and grounded the mast and coax this weekend. I was only able to get about 4-feet deep with the grounding rod, hopefully that is enough.

Question: Does it matter where the grounding block is located, with respect to my Kitz-tech KT-200 pre-amp (upstream or downstream from it). I currently have the grounding block downstream from the pre-amp, since that would be the prototypical configuration if the pre-amp were mast-mounted. But since my pre-amp is at the base of the tree, I appear to have a choice...

I did a bit of research on the mast and coax grounding.

Mast grounding: As I understand it, the main purpose is to prevent static charge build-up at the antenna, thereby reducing the likelihood of a lightning strike. Connection to any decent ground-stake should suffice for this.

Coax shield-grounding: This should be tied to the same ground that the house and its appliances (e.g. my TV) use. Anything else could result in a floating ground or a ground loop.

Therefore, I think I should move my grounding block to the house-side so that I can utilize the house ground-stake, rather than my ground-stake at the tree. Since the entry point of my coax into the house is on the opposite side of the house from my house ground-stake, would it be ok to just connect the grounding-block to the ground-wire (bare wire) of a convenient 110V outlet, such as the outlet that I'm using to power the preamp's power-inserter?

Thank you. I couldn't figure out where the antenna was located when looking at the satellite view.
You are in a gray area as far as the NEC is concerned. I would treat it like a ham antenna on a tower.
Antenna System Grounding Requirements
http://www.reeve.com/Documents/Artic...ents_Reeve.pdf

A strict interpretation requires a 6 gauge copper conductor between the ground rod at the base of the tree and the house electrical system ground. That would be inconvenient and expensive.

Most hams ground the antenna and the coax at the base of the tower, and ground the coax again at the house to the house electrical system ground. The coax shield then acts as a bond between the two grounds instead of the 6 gauge copper wire.

This is also the method used by many satellite installers. The dish and coax are grounded at the base of a ground mounted dish, and the coax shield is again grounded at the house to the house electrical system ground. The coax used is quad shield that has a lower resistance for a more effective grounding bond. Other dish installers use coax with a 17 gauge copper coated steel messenger wire for grounding the dish, but it is not grounded at the dish.
http://www.dbsinstall.com/diy/Grounding-2.asp

see other parts at that site

Todd Humphrey doesn't speak for the NFPA that publishes the NEC code, but he has some ideas that are helpful. The local electrical inspector (AHJ, authority having jurisdiction) has the final say if you are willing to get him involved. Some inspectors are more friendly than others; a local electrician could tell you.

You get to decide what method to use.

The google satellite view is about 4 years old. I built the barn/sugarhouse 3 years ago.

Thanks for the suggestions. I think I will ground the coax shield in both places (tree and house).

Thinking about ADTech's recommendation some more, I think I'm going to move my UVSJ from the top of the tree to the bottom of the tree, and use separate down-leads for UHF and VHF. I already have two downleads installed anyway: the original RG-6 downlead and my current RG-11. Extending this line of thought, I think my VHF signal is strong enough that I can get away without amplifying it, and only amplify my UHF feedline. Moving the UVSJ downstream of the amplifier could save me the insertion loss on the UHF side. Does that make sense?

Does the Antennas Direct UVSJ pass power on the UHF side? If not, is there a make/model that does?

Yes, it does. ;)

Since it's been pretty quite on the forum lately, I guess I'll report on the two amplification configurations I have tried recently.

Configuration #1: Amplify UHF-only upstream of UVSJ, by utilizing the UHF-power-pass capability of the Antennas Direct UVSJ (VHF stays unamplified)
Configuration #2: Amplify UHF+VHF downstream of Antennas Direct UVSJ

Configuration #1 gave me about a 1 dB stronger signal on WFFF (my weakest UHF station). But it came at the cost of about 7 dB on the VHF channel WVNY, which I had to leave unamplified for that configuration. Even though WVNY shows an SNR of 21 dB at the TV for configuration #1 (15 dB required for reception), I decided to use configuration #2 for now. Either one seems equivalent in terms of reception, and both provide about 6 dB more than the minimum needed for reliable reception of the weakest channel...

Current overall setup:
Antennas: DB8e and MCM-30-2476 at about 55-ft AGL in a pine tree. The DB8e uses 50-ft of RG-11 to base of tree, the MCM-30-2476 uses 50-ft of RG-6. Signals combined at base of tree using Antennas Direct UVSJ, then Kitztech KT-200 preamp, then 150-feet of direct-burial-grade RG-6 to house (in underground conduit, belt+suspenders), then KT power inserter, then 30-ft of RG-6 to TV.

My current actual reception report:
WVNY, Real 13, (TVFool NM=6.6 dB): SNR at TV= 29 dB
WPTZ, Real 14, (TVFool NM=9.2 dB): SNR at TV= 29 dB
WCAX, Real 22, (TVFool NM=8.2 dB): SNR at TV= 29 dB
WETK, Real 32, (TVFool NM=-2.2 dB): SNR at TV= 26 dB
WFFF, Real 43, (TVFool NM=-5.8 dB): SNR at TV= 22 dB


Just out of curiosity, does anyone know if there is a UVSJ that passes power on both ports? If so, does anyone know of a pre-amp system that can power two pre-amps using just one power inserter?

No, but it wouldn't be hard to modify ours so it would do so. It would involve opening it up and soldering a coil between the VHF in and the common port terminals, just like the internal UHF filter is bypassed.

You can also use two SAT/TV diplexers in a back-to-back configuration to bypass a non-power-passing component.

I have both a distribution amp in my attic and a preamp out on the mast running from a single power inserter in my living room. I'd have to go up in the attic and review how I did it, I just threw it together out of what I had in the "junk box" and it probably wouldn't be the "optimized" solution.

Channel Sharing
 

I have noticed that after the re-pack, WNNE real-25 from Mount Ascutney (which I believe is a local translator for WPTZ on real-14 from Mount Mansfield) will be entering a channel sharing agreement with WPTZ. On rabbitears.info, this shows as 25 --> Sh. 14 for WNNE.

What exactly does this mean? My guess is that the ch-25 signal from Mount Ascutney will cease, and that the periodically-displayed station-ID overlay for WPTZ will now say WPTZ and WNNE, instead of just WPTZ. Is that right? It doesn't mean that the tower that was broadcasting 25 on Mount Ascutney will switch to 14, which would be big co-channel interference problem, right?

What is the short summary of the reasons behind these so-called channel sharing agreements?

It means that the station currently transmitting on 25 will go off the air and they will become a "guest" on the "host's" post-repack channel and will be treated like a sub-channel as far as your tuner is concerned.

"Channel sharing" is exactly what it says. There will be two stations on one signal, sharing the bandwidth under the terms of their contractual agreement. The guest will pay the host for the right to use an allocated portion of the channel's bandwidth.

It's weird, because WNNE is already broadcasting the exact same content as as WPTZ 5.1 (NBC). In fact, I think WNNE is a translator for WPTZ. Also, WPTZ already has three channels on its signal: NBC (1080i), CW (720p), and MeTV (480i). Could they squeeze one more sub-channel channel into the signal? Even if they could, it wouldn't make any sense to have two subchannels with exactly the same content.

Clarification: (from Wikipedia)
WNNE serves as a full-time satellite of WPTZ (channel 5), the NBC affiliate for Plattsburgh, New York and Burlington, Vermont. WNNE airs the same broadcast schedule as its parent station, but airs some limited advertising specific to the Upper Valley (Hanover NH area) that is added to WPTZ's programming.

The Channel-sharing arrangement took effect last week. WNNE (real 25, virtual 31.1, NBC) which had the exact same content as WPTZ (real 14, virtual 5.1, NBC) ceased broadcasting from its tower on Mount Ascutney. On WPTZ's bundle, virtual channel 5.2 (CW) is gone- it has moved up to 31.1 on my virtual dial and now shows a WNNE word-mark at the top of each hour. So essentially, WNNE is now a CW affiliate instead of an NBC affiliate. Inspection of the channel 31.1 signal on my Sony Bravia shows it is being broadcast on Real-14 (WPTZ's frequency), which I guess is the essence of channel sharing.

At the end of the day, I personally didn't lose any programming content, since I was receiving both WNNE and WPTZ signals. But anyone who couldn't get WPTZ in my area (the vast majority of folks) essentially lost their NBC affiliate when WNNE stopped broadcasting locally as part of this "Channel Sharing" arrangement. Kind of a bum deal.

Yes On the solid signal HDB91 side by side 3ft apart feed line's the same length and
Beside free shipping on the HDB,91 I did and it work's well you will be happy with it
I was!!lol with my 150ft tower receive of channel's was right on the money lol
And yes one feed line for vhf&one for uhf and I suggest you use RG11.for best results.
Lol good luck with your antenna set-up and be safe on the roof and look out for power lines when installing an outdoor tv antenna!!!
PS,or maybe you should just go with the Winegrud,8200U
With a channel master 7777amp..And for get about that
OTHER mess and I am sure you will be happy as a pig,in sht.lol
And up north look out becuse BROADCASTING station for all
Of Boston Mass and so on for Over the aire Broadcasting
That thay say is going too nock your soxs off lol and besides
In this neck of the woods the fcc suggests that you use a combow outdoor tv antenna like the 8200u.I hope this put's
A good spin on things and up north dount for get the channel master 7777amp becuse their is no worries about over load.
With all IT'S Montana and so on lol

Yes and you should probably
 

Yes and you should probably start seeing low band vhf as well.
Up north in are neck of the woods in Boston and New York city.And so on
And that is why the Fcc.suggest you buy a combination hi&low band vhf/uh F like the 8200u.
Outdoor tv antennas not just a uhf or hi vhf outdoor tv antenna like the
DB8,the HDB91 and the antennas Direct,91XG,so dount cut your self short
When getting an outdoor tv antenna and I suggest that you use RG,11,for
Best results in installing an outdoor tv antenna,good luck and if you
Dount believe me go to Fcc, .com good luck with your antenna set-up and
What you choose to do.

I'd rather not have this discussion be derailed by antenna and preamp recommendations for a problem that is already solved. My setup is complete and working swimmingly, as described in posts #90 and #98.



Back to Channel Sharing...

Has anyone else experienced a so-called Channel Sharing agreement like what I have described in post #103? One in which, for most people, basically amounts to a station just going off the air? Is this common, and will it be more common as the Repack moves forward?

IT'S time too start a new thread ???
All you should probably do is go with Rg11,
Instead of the 6

https://www.fcc.gov/consumers/guides...tion?from=home

It is only common for the channels that agreed to that arrangement during the auction. The channel that stays on the air is called the Host (H); the channel that gave up its license is called the Guest (G).

In my hometown of Buffalo, NY, the longtime CBS affiliate, WIVB, turned in their license. They had always broadcast from Colden, NY, which is elevated and about 20 miles south of Buffalo. They are now "channel sharing" with the CW affiliate, WNLO, which broadcasts from Grand Island, about 5 miles
north of Buffalo. Grand Island is just about at sea level. All the folks in the southtowns who received the Colden signal cleanly either receive no signal at all or a very poor signal from Grand Island. In essence, many have lost CBS programming.

I have the opportunity to borrow my neighbor's 60-ft man-lift again this weekend to service my tree-mounted antenna array. This may be the last time I get to do any maintenance up there for several years. I'm planning to re-aim and re-secure my 30-2476 VHF antenna which has been blown off by 45-degrees. I was also planning on replacing some my non-UV-stabilized zip ties with UV-stabilized ones, and putting dielectric grease in the barrel connectors.

My questions are what kind of dielectric grease should I use, and is there anything else I should do while I'm up there, considering I probably wont have access again for several years?

Thanks in advance!

Hi jrgagne99: I use and would recommend Coax-Seal. It will stay put on your connections as long as you need it and does come off fairly easily when you want to remove it. I've only read a very few posters across the Net not liking it. The link below will give you their information and you can buy it off Amazon as well. (I am in no way affiliated with Coax-Seal. Just a hard core OTA enthusiast offering a tip).

http://coaxseal.com

As far as dielectric grease goes, I use Caig DeoxIT D5 spray to improve conductivity. But that's just been my preference. Although they do have grease too. Someone else may have the "cat's meow" on grease. You can find them at: www.caig.com

Stay safe up there in the trees and please post back your results as I would be interested in seeing how everything came out.

All the best!

Silicone grease is often used on O-rings. That is what Andrew (now Commscope) packaged with their connectors for high powered coax called Heliax. I never bought any silicone grease because I’ve always had some left over. Silicone based O-ring grease is available from Lowe’s.

https://www.lowes.com/pd/aqua-ez-o-r...iABEgK3APD_BwE

I prefer silicone fusing tape to the coax seal. It adheres to itself and fuses together. It leaves no residue when removed. You can simply slit it gently with a razor knife and peel it off easily if you have to remove it. The bond is permanent, waterproof, resists weathering and UV deterioration. It stretches around uneven shapes and forms a really tight seal. I use it for all my TV and ham radio antenna connections. I have opened up connections that are over 10 years old and found them just like the day I installed them. It is really great stuff.

I was reluctant to undo the coax connections up in the tree, for fear of messing something up unnecessarily. So rather than take the connections apart and applying grease, I decided to just use the silicone fusing tape that Tim recommended. I wrapped the tape tightly around each coax connection and it seemed like it would be a pretty water-resistant seal. I also replaced some of the zip-ties up there with UV-resistant versions and trimmed a couple of branches while I was there. Hopefully the setup will continue to function well (all five major networks from 72.5 miles away) for many years to come.