Winegard HD8200U VHF question
 

Hi, I'm new to this forum and also somewhat to the wonderful world of antenna theory and reality!

I have a cabin in a HOA governed gated community up in Show Low, AZ. There are only two TV channels relatively close retransmitting from Phoenix. Both Fox Channel 10 (transmits on real channel 7 VHF-High) and PBS KAET Channel 8 (transmits on real Channel 3 VHF-Low) transmitters are located at Porter Mountain about 8 miles away. Due to HOA requirements the antenna is installed in the attic at 115 degrees azimuth towards Porter Mountain.

http://www.tvfool.com/?option=com_wr...903872956fdaf7

I probably went over the top and bought/installed a Winegard 8200U in the attic together with (from memory) a Channel Master Pre-Amp. I get good reception with FOX on real channel 7 but can only occasionally lock into PBS on real channel 3.

While performing physical checks of the antenna I noticed that with the antenna combiner cartridge removed that resistance between the UHF terminals was >200 ohms but for VHF the resistance is <2 ohms which does not seem right to me? Physical inspection (in a very tight attic space) revealed no issues including high resistance between the VHF antenna rods and the central antenna rod used for mounting which is what I expected. I may be chasing a "non-issue" since FOX on real channel 7 comes in without problems. Question: Is there an electrical diagram for the Winegard 8200 antenna available? Thoughts/Comments on my findings?

Lastly, I've read that a Pre-amp does not help for VHF-Low channels and would do better with it removed? Thoughts?

Thanks in advance for your thoughts/comments,

Regards,
Peter J.
Phoenix, Arizona

Show Low is a really nice place. I was there last April when Run For The Fallen came through. I actually RAN through Show Low! Now, running at 7,000 elevation when you're used to 700 feet is hard enough, but throw in that I ain't as young as I used to be... well, let's just say I was really gasping! I'm the old guy on the right!


https://www.runforthefallen.org/wp-c...2-1024x683.jpg




Couple of things:

1. Re the HOA's governance of antennas: It is is probably unlawful (except under very narrow circumstances). See https://www.fcc.gov/consumers/guides...tellite-dishes

2. Remove the pre-amplifier and retest. For strong signal zones such as yours is calculated to be, they usually create new problems where none existed.

Try that and see what happens. VHF low is plagued with reception issues caused by local electrical noise so it might take some work to see if that's the case.

Winegard has a video floating around that shows how to test for a failed coupler board. It involves removing the board and making a substitute connection with a common matching transformer equipped with alligator clips. Rabbit73 probably has it bookmarked, hopefully he'll drop in and comment. I've never poked around inside their coupler box.

ADTech,

Show Low at 6300ft and the White Mountains are a great place to hide out during the Summer when we hit 110+ Fahrenheit down in Phoenix! ... You've got to acclimatize yourself to this altitude before doing any serious running!!

Many Thanks for your suggestions, I'll definitely remove the Pre-amp as a test next time I'm up at the Cabin. As for the concern mentioned regarding low resistance across the VHF poles, please note this low VHF resistance measurement was taken at the Antenna with the antenna combiner cartridge removed (hence the combiner cartridge is outside of the equation).

I've seen the Winegard video regarding a possible failed antenna combiner cartridge. In fact, the method recommended by Rabbit73 to test whether the cartridge is faulty or not by removing the cartridge and connecting a 300 ohm to 75 ohm impedance transformer directly to the VHF antenna rails is the primary reason why I question the approx 2 ohm reading I get across the VHF rails with my multimeter.

Thanks again,
Peter J.

Yeah, I only had two days to acclimate to the altitude on that trip as we got to Pinetop on Thursday afternoon. Needed more. By Sunday afternoon we were up in Holbrook and it was a lot easier.


I've never examined the Winegard arrangement so I don't know what to expect for a DC resistance. I also do not know if that is a valid and useful test or a red herring. You might contact them directly and ask their support staff and see if anyone knows.



Since it sounds like this is a location that is visited rather than a primary residence, I'd approach it with a two-step plan. Pick up or order the parts to make the test jig (balun & clips) so you have them if needed. Plan on removing the amp and its power inserter as your first step.


Best of luck!

Nice to see so many others enjoying Arizona!
I agree that your HOA most likely cannot legally enforce
having no visible outdoor antennas. I also agree that
VHF low is always going to have interference issues.
In your general area, do you see any antennas pointed
toward Flagstaff???? It is possible, in some areas to
receive KNAZ, NBC and in a few elevated pockets, with
few pines to the Northwest, some translators on Mt Eldon,
in Flagstaff. Those translators on Porter Mtn are extremely
weak, even for VHF. There are no really good or easy
solutions.......

Hello, Peter; welcome to the forum.

You need some kind of antenna for K03FB on VHF-Low channel 3. There aren't many choices; the 8200 was a good choice.

The signals will be attenuated by the attic location, but if you can receive K07OJ that is running only 33 watts ERP, you should be able to receive K03FB running 300 watts ERP.

Resistance measurements with a DC ohmmeter are inconclusive when you are working with RF.
You do have an issue, but we haven't figured it out yet.

There could be a problem with the antenna that allows it to receive 7 better than 3, or it could be, as ADTech mentioned, you have electrical interference on VHF-Low that raises the noise floor and reduces the SNR of 3.

I favor the second possibility because I have made noise measurements for indoor antenna locations that indicate much stronger signals are needed on VHF-Low than on VHF-High for good reception. Noise can come from LED and CFL lamps, electric motors, battery chargers, and switchmode power supplies (AC adapter) for laptops.

https://i.imgur.com/aAU1EBY.png

Not that I know of.

On VHF-Low, a preamp makes the signal and the noise stronger, so you end up right where you started with no improvement.

Try it.

Which CM preamp are you using?

Did you actually try to receive 3 and 7 with the balun attached to the VHF wires?

https://i.imgur.com/9dU9hYm.jpg

If you did, and 7 was better than 3, you can try a channel 3 folded dipole as an antenna for 3.

If you still can't receive 3, either they are running at reduced power or you have a high noise level on VHF-Low from electrical interference. I use a portable radio tuned to a vacant channel on the AM broadcast band, first the low end then the high end, to hunt for noise sources.

https://i.imgur.com/tcbmnmI.jpg

Rabbit73, Thanks for your response. See my initial comments below,

"Did you actually try to receive 3 and 7 with the balun attached to the VHF wires?"

Nope, but I'll be up at the cabin next weekend and will test.

"If you did, and 7 was better than 3, you can try a channel 3 folded dipole as an antenna for 3"

Good idea, I'll go looking for some 300 ohm twin-lead, make up an 88" folded dipole and test.

"Which CM preamp are you using? "

Not sure, I'll check while up at the cabin next weekend and report back.

Thanks again,
Peter J.
Phoenix, Arizona

Rabbit73 et all,

I made it up to Show Low for the weekend and made some additional tests based upon your recommendations:

"Did you actually try to receive 3 and 7 with the balun attached to the VHF wires?"

Testing completed this morning at the HD8200U antenna mounted in the attic with a portable Television connected directly to the balun (bypassing pre-amp and cabin coax) and a second test with the balun removed and VHF connected using crocodile clips with a 300 to 75 ohm converter.

In both cases, real channel 7 comes in with good quality but PBS on real channel 3 is not picked up during a scan. After tweaking antenna direction for real channel 7, I note through my main TV and PC that the Hauppauge signal monitor shows a SNR in the upper 20's to low 30's but again real channel 3 cannot be found during the scan.

"If you did, and 7 was better than 3, you can try a channel 3 folded dipole as an antenna for 3"

As suggested, I built a real channel 3 folded dipole (88") and tested both outside on the cabin deck and up in the attic. Both tests resulted in real channel 7 being scanned and providing a reasonable signal, real channel 3 however could not be found during scans.

"Which CM preamp are you using? "

I'm using a CM7777 pre-amp. But based on the above test results the pre-amp is not the cause of my real channel 3 reception problems :-)

*********************
The above results indicate to me that my HD8200U antenna is likely working just fine. The balun, pre-amp and cabin coax cabling are not causing problems. Antenna direction is fine since I was able to tweak against real channel 7 which is also located on Porter Mountain…… Other Thoughts Welcome!!

I do have the attic and trees in the LOS to Porter Mountain but would have thought channel 3 would have provided better penetration than channel 7?? Low power of 300 watts ERP bothers me compared to other stations around the nation on VHF-Low?? I guess that I now need to look at interference issues in the area but not sure how one would go about resolving (unless it is being generated from within the home).

One last comment, I have driven around my neighborhood and have not found other homes with external OTA antennas, all seem to be using cable or direct/dish satellite TV.

Thanks again,
Peter J.
Phoenix, Arizona

rabbitears.info shows K03FB on the air:
https://rabbitears.info//market.php?...callsign=K03FB

Either it isn't on the air or you have a high noise level on CH3.

I suggest you call the KAET station engineer at ASU.

Ian MacSpadden
Dir. Broadcast Engineering and Operations
Arizona State University
555 N. Central Avenue Suite 302
Phoenix, AZ 85004
US Phone:+1 (602) 496-1774
Email:Ian.MacSpadden@asu.edu

Greetings from Prescott, AZ!
I have found that the four KAET translators I receive from Williams,
Flagstaff, Mingus Mtn and Prescott are all unusual in their performance.
I receive the best signal when the antennas are turned about 45 degrees.
I also note that KAET's translators, of which there are many, do not seem
to be a priority for their engineer. Finally, I believe the Show Low translator
is 270 watts on a good day.

Rabbit73, Great comments, Thanks!

I ran a test this morning using the Hauppauge signal monitor and scanning real channel 3 with the Winegard HD8200U. I found there was NOT a measurable signal to lock onto for channel 3, same test with real channel 7 (FOX) worked fine.

I then took the channel 3 folded dipole (88") and a portable television out on the road and found that even below the transmitter at Porter Mountain there is not a signal on channel 3 (K03FB-PBS). Again real channel 7 transmitting from the same location was fine.

The last time I was in Show Low a month ago I'm certain the transmitter was operational. I'll contact the KAET station engineer tomorrow per your suggestion.

Regards,
Peter J.
Phoenix, AZ

JoeAZ,

Not sure I understand the need to move the antenna approx 45 degrees to receive a good signal on PBS??

I'll contact the PBS station engineer and try to find out why the Porter Mountain transmitter is apparently down.

Thanks,
Peter J

"Not sure I understand the need to move the antenna approx 45 degrees to receive a good signal on PBS?? "

Hi Johnsonbrits,

I have found that when I have UHF antennas mounted horizontal/
perpendicular to the ground, (+) the KAET signals are pretty marginal.
When I rotate the UHF antennas like an "X," the signals most always
improve. I believe it has to do with polarization but supposedly, most
all tv stations have the same polarization. I do not know if the low VHF
Show Low translator would follow suit but thought it might be worth
a try......... Good Luck!

Rabbit73, Great comments, Thanks!

I ran a test this morning using the Hauppauge signal monitor and scanning real channel 3 with the Winegard HD8200U. I found there was NOT a measurable signal to lock onto for channel 3, same test with real channel 7 (FOX) worked fine.

I then took the channel 3 folded dipole (88") and a portable television out on the road and found that even below the transmitter at Porter Mountain there is not a signal on channel 3 (K03FB-PBS). Again real channel 7 transmitting from the same location was fine.

The last time I was in Show Low a month ago I'm certain the transmitter was operational. I'll contact the KAET station engineer tomorrow per your suggestion.

Regards,
Peter J.
Phoenix, AZ
********************************************

Greetings, Just an update on my reception issues in Show Low of Channel 3 K0FB (KAET satellite re-transmitter from Phoenix).

The last time I was in Show Low at the cabin (last month) I found the K0FB transmitter on Porter Mountain to be down and hence no reception. After contacting the KAET operations engineer in Phoenix it was confirmed the transmitter was down and a crew would be up from Phoenix to fix within a day or two.

I came back up to Show Low this past weekend and after a false start, found K0FB to be up and transmitting, although I still could not receive a watchable channel at my location (very heavy pixalization). FOX on Channel 7, no problems.

I removed the CM777 pre-amp from the attic run to the TV since a concern was raised that that this particular pre-amp was likely overkill for a transmitter only 8 miles away and might be overloading the receiver. - no noticeable improvement.

I have a network router and OBI VoIP modem powered and physically close to the TV and Laptop Hauppauge stick. Removing the AC power from the same AC outlet and moving to a separate feed showed a reduction in pixalization for K0FB - Interesting!

I then powered down the laptop with the Hauppauge TV stick and boom, up came K0FB with minimal pixalizations. Not having the Hauppauge signal monitor I cannot read the SNR. However the TV signal monitor shows a consistent signal strength of "normal - yellow" vs Fox on channel 7 of "Good - Green".

I'm extremely pleased to finally receive VHF-Low channel 3 fairly consistently. I then purchased an EMI/RFI AC adapter from Radio shack for the television receiver but still receive noise which I'm thinking is also RF induced from the AC power wiring going to the laptop and other switching power supplies since as I move the AC power lines around by the TV pixalization pops up until I move the power cable to another location

Any thoughts on how to eliminate the noise induced into the AC power wiring? I was thinking of a 6 foot shielded AC extension cord to keep the various power supplies physically removed from the TV receiver would help?

Comments welcome!

Regards,
Peter Johnson
Phoenix, AZ

Thank you for the update, Peter. Glad to hear you were able to get them to put the transmitter back on the air.

You were able to reduce the noise interference that was reducing the SNR of the channel 3 signal, so you are almost there.

It is possible that you have some interference that is conducted through the power line, but you most likely also have some radiated (through the air) noise interference that is picked up by the antenna.

First, make sure that the coax is grounded with a grounding block that is connected to the house electrical system ground; it might help. Next, use a portable battery operated radio tuned to a vacant channel on the AM broadcast to hunt for sources of radiated noise interference, as I mentioned in post #7. Most AM portable radios have a loopstick antenna that is directional which will help you locate the interference source.

…"Any thoughts on how to eliminate the noise induced into the AC power wiring? I was thinking of a 6 foot shielded AC extension cord to keep the various power supplies physically removed from the TV receiver would help?"...

You could try some ferrite cores on your cables. I use them at work to stop noise from entering USB cables. Even the expensive, well shielded USB cables benefit from having one, (or two), installed on each end of the cable.

You can get them on Amazon cheaply enough to try them. They just snap on the cables/wires, so quite easy to try.

Most likely the noise is radiated and is being picked up by the antenna rather than the coaxial feedline. The ferrites on your coax cable will likely neither help nor hurt. Ditto for a shielded power cable for the "various power supplies". If those devices were appropriately tested for FCC Part B compliance, they would have been tested for both radiated and conducted emissions.

So what's a little noise

A little noise can make it impossible to receive a channel 3 signal which is on VHF-Low, your favorite band. And, Johnsonbrits who posted this thread, has one of your favorite antennas, the Winegard HD8200U.

Quote from rabbit73:

"It is possible that you have some interference that is conducted through the power line, but you most likely also have some radiated (through the air) noise interference that is picked up by the antenna.

First, make sure that the coax is grounded with a grounding block that is connected to the house electrical system ground; it might help. Next, use a portable battery operated radio tuned to a vacant channel on the AM broadcast to hunt for sources of radiated noise interference, as I mentioned in post #7. Most AM portable radios have a loopstick antenna that is directional which will help you locate the interference source. "

I had to return to Phoenix and won't be up to the Cabin in Show Low for a few weeks. However, based on some additional testing before I left these were my findings:- (Don't know if they make sense to anyone, I guess RF noise/interference stuff isn't necessarily logical :-)

1) Grounded the Antenna coax lead at the TV to house ground as suggested but noted no difference in signal quality.
2) With an old analog AM portable radio tuned to no station and just listening for static type noise I noticed :-
a. Major interference coming from my powered up laptop which is located below the television. Noise to the extent that Channel 3 K0FB is blocked and cannot be scanned (laptop is used for streaming - e.g. U-tubeTV, Netflix, remote access to Hauppauge on home computer etc.)
b. With Laptop powered down from keyboard but AC power supply still plugged in, significant noise is detected from both the TV (inexpensive older Scepter 40" LCD) and remote laptop switching power supply. However, moving the laptop switching power supply and it's AC/DC output wiring around from the proximity of the TV, K0FB channel 3 would pop-up but remain somewhat pixalized, moving the switching power supply in a certain direction and location reduced the pixalization to a watchable channel.
c. With Laptop powered down and switching power supply unplugged from the wall, interference was minimal until I moved the power supply and wiring in front of the TV when significant pixalization would return (note, no power is applied at this time), moving the Laptop switching power supply to it's previous location and signal improved with minimal pixalization.


I can live with powering down the laptop to reduce interference when watching OTA K0FB channel 3 but would like to find a decent solution to block interference from the laptop switching power supply and cabling (best location from my testing was to place the physical switching power supply in front of the stone fireplace which won't work long term for the wife :-)

Many thanks for all your feedback and comments/recommendations to date!

Regards,
Peter Johnson
Phoenix, AZ

Switching power supplies are a common culprit for creating interference into the VHF frequencies. https://en.wikipedia.org/wiki/Switch...e_power_supply

Is the power supply OEM to that laptop or an aftermarket replacement. If not OEM, then that's the first thing to consider replacing. Or, you could bring along a metal container to drop it into and see if you can suppress the radiated emissions that are interfering with reception.

Other options include maximizing distance between that laptop and its power supply relative to the antenna or, perhaps, relocating them (or the antenna) so they are at somewhat of a right angle to the antenna.

Perhaps a new laptop?

I’d try two of these:

https://www.mouser.com/ProductDetail...CABEgIC1PD_BwE

Put one on the power cord close to the power supply, the other on the DC cable; again close to the power supply end of the cord.

You may also find these on old VGA monitor cables.

Thanks for the recommendation, I've placed an order for ferrite core suppressors and will try them on my next visit to the cabin.

Peter

ADtech, The Laptop is an ASUS unit that was given to me by my son-in-law. I believe the power supply is original but will need to verify on my next trip up to the cabin.

Good idea! - I have an empty cookie/biscuit tin that I'll place the switching power supply into as a test on my next trip up to the cabin. Does the tin need to be grounded?

Peter

be 4 you do that by putting it in to a tin ask your
Local firer department be for it goes up in smoke and you loos ever thing
Including your cabin ask the manufacturer what they Suggest be 4 u put it in
A TIN!!!

Thank you for making the thorough tests; you are on the right track.

Interference problems can be difficult to solve. Interference can be conducted, radiated, or both and you can have more than one source of interference.
That's interesting. Am I understanding it right? With the laptop off and its power supply not plugged in, you still have interference? That would indicate another source of interference besides the laptop power supply.

My original thought was that the primary source of interference is from the laptop power supply.

Does the laptop have an internal battery? Does the laptop cause interference when it is running on its battery and the power supply is not plugged in to AC and not connected to the laptop?

Are you using the TV tuner or the Hauppauge tuner to receive channel 3?
There are two types of power supplies: linear and switching. The older linear power supplies are heavier because they have a power transformer, are less efficient, but don't create much interference. The newer switching power supplies are lighter, much more efficient, but can create a lot of interference if not properly filtered in the original design. In some countries, switching power supplies are required because of their better energy efficiency.

In theory, it is possible to substitute a linear power supply for the switcher; lower efficiency, but less noise interference.

Can you bring a newer laptop up to the Cabin for a test? The AC adapters for the newer laptops have better filtering.

How far away from the TV is the antenna, the direct distance, not the coax length?

Use a solar panel change or a battery backup pack like a jump box for back up POWER
To charge up the international battery on the laptop there is all kinds of stuff on the
Internet for like RV camping but it is all 12volts stuff and so is the labtop. I think that
Maybe something
like this will fix your problem.We'll good luck and have a good day.
HAPPY mother's day everyone on the form!!!

I'm betting the ferrite cores are going to help a lot. I use them at work when faced with un-explainable issues on computer equipment. Sometimes it's just like magic.