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Old 11-Apr-2016, 1:19 AM   #21
rabbit73
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If you are using the high and common ports and it blocks 13, they sent you the wrong thing or it is defective.

It doesn't need to be power passing if it is between the antenna and the input of a preamp if you use one.

I have never been impressed with that brand; why didn't you buy one that I suggested?

A good HLSJ doesn't block UHF coming in the high port.



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Last edited by rabbit73; 11-Apr-2016 at 1:25 AM.
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Old 11-Apr-2016, 4:49 AM   #22
chris1379
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I only had a few bucks in PayPal so I got the cheapest on Ebay. Who has the best shipping prices for a small item like this?

Do you happen to know what is inside an HLSJ? I found this thread on FM Traps. I'm just curious. I could probably make one, or at least the high-pass half. I'm trying an FM trap now.
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Old 11-Apr-2016, 10:42 AM   #23
rabbit73
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What good is cheap shipping if you got the wrong thing?

What FM trap are you trying?
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Last edited by rabbit73; 11-Apr-2016 at 10:52 AM.
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Old 11-Apr-2016, 3:09 PM   #24
chris1379
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Quote:
Originally Posted by rabbit73 View Post
What good is cheap shipping if you got the wrong thing?
Not much at all, lol. I didn't realize you were recommending that particular brand. I do plan on getting a couple of them as soon as I can.

Quote:
Originally Posted by rabbit73 View Post
What FM trap are you trying?
The one from MCM with the nice pictures and schematic in the thread. I didn't make a PCB. I just built it into a metal RF box from an old satellite receiver. I can't fine tune it without proper equipment but it works well enough to confirm that this HLSJ is not working properly. WOWK has a strong signal with some dropouts and WCHS has a weaker signal but about the same performance. I even pulled in WLPX, ION with the antenna aimed for WOWK. That's way down on the list. I was actually able to connect an amplifier without overloading it and it seems to help the RCA tuner a little.
Attached Images
File Type: jpg 20160411_111349.jpg (415.2 KB, 371 views)

Last edited by chris1379; 11-Apr-2016 at 3:24 PM.
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Old 11-Apr-2016, 3:16 PM   #25
rabbit73
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Good test to confirm that your HLSJ is NOT doing what it should.

The original MCM FM filter is a good one, but is hard to find now.
http://www.amazon.com/In-Line-Trap-N.../dp/B00EIAFHLK

Radio Shack discontinued their FM trap and Antennas Direct is running low on stock, and will not be replaced. Even HLSJs are getting hard to find. All that will be left is DIY or custom built.
https://www.google.com/?gws_rd=ssl#q...ematic+diagram

The Radio Shack FM filter has poor attenuation at the 88 MHz end to protect TV channel 6, but good attenuation at the 108 MHz end. The AD filter is just the opposite. Neither one would be good for you because you have strong signals at both ends.



Your test results sound like you are on the right track.
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Last edited by rabbit73; 11-Apr-2016 at 3:36 PM.
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Old 11-Apr-2016, 3:33 PM   #26
chris1379
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Rabbit73, I think I was editing when you sent that last post. I added a picture (wish I could show the picture or a thumbnail.
What I'm hoping to find out is I can raise the antenna higher now. I think maybe the FM interference was increasing with antenna height also and overloading the tuner.

Thanks everyone. I'll post updates when I find out.
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Old 11-Apr-2016, 6:15 PM   #27
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Quote:
I added a picture (wish I could show the picture or a thumbnail.
I can display it for you; nice job, chris.



This is what the MCM FM Trap looks like inside:



diagram



Quote:
Do you happen to know what is inside an HLSJ?
Inside is a low pass filter and a high pass filter, just as there is inside a UVSJ, but for different frequencies. The general term for these filters is a diplexer. All UVSJs are diplexers, but not all diplexers are UVSJs.

Here is a DIY 5-pole Diplexer, AKA UVSJ:



DIY photos
http://www.is0grb.it/duplexer/

DIY 3-pole HLSJ; 5-pole would be better:



source:
http://www.electro-tech-online.com/t...ircuit.122182/
post #12
http://www.electro-tech-online.com/t.../#post-1008775
Attached Images
File Type: jpg chris1379TVFdiyFMfilter2.jpg (225.9 KB, 2102 views)
File Type: jpg Inside%20MCM%20FM%20Trap%20#6%20&%20#8.jpg (115.7 KB, 1646 views)
File Type: jpg MCM FM Trap Sim.JPG (111.4 KB, 2136 views)
File Type: jpg VHF-UHF Diplexer SM0HX.jpg (22.8 KB, 3520 views)
File Type: jpg VHF Hi-Low Splitter Diag_1.jpg (142.7 KB, 1894 views)
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Last edited by rabbit73; 12-Apr-2016 at 11:32 AM.
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Old 14-Apr-2016, 2:38 AM   #28
chris1379
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Thanks for the information. I looked inside the HLSJ I got and the component values are more consistent with UHF/VHF splitter. I left the low side alone and put a 5 pole chebyshev on the high side. 160 MHz gave me convenient values.

Part Values
Part Chebyshev 0.1 DB
L1 0.048 uH
L2 0.048 uH
C1 10.19 pF
C2 5.92 pF
C3 10.19 pF


Attached Images
File Type: gif lchpf5.gif (2.2 KB, 1390 views)
File Type: jpg 20160413_221215a.jpg (338.6 KB, 1477 views)

Last edited by chris1379; 14-Apr-2016 at 2:47 AM.
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Old 14-Apr-2016, 6:43 PM   #29
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I'm not sure where to go from here. I can buy 2 HLSJ's to replace my homemade FM trap and modified HLSJ but I don't think it will matter . What works best is to have a filter, amplifier, and then a second filter. The amp is a RS 15-1108 that is supposed to have an outdoor amp, which I don't have. I'm still thinking of buying a better outdoor matching transformer. I can get all the channels I want on the RCA converter box but not without moving the antenna a few degrees. The strange part is that the direction doesn't correspond with the report. I'm going to use virtual channel numbers for a minute. If I have the antenna pointed at 3,13, and 29, I have to turn it counter clockwise to get 8 and 11. They should be clockwise. Channels 3 and 30 actually have 2 strong points. Raising the antenna higher decreases the weak signals. This still doesn't make sense unless the roof is acting as a reflector.

So, what is an easy way to rotate an antenna without digging it into the ground while rotating? Put it in a bigger pipe? I can reach it through an open window. If I added a second antenna, can I just use a splitter in reverse or do I need to separate the frequencies?

Last edited by chris1379; 14-Apr-2016 at 6:48 PM.
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Old 14-Apr-2016, 8:17 PM   #30
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Please limit the width of your photos to about 800 pixels. I have a hard time reading your posts when they are so wide.
Quote:
I'm not sure where to go from here.
Don't make any more tests until you ground the coax with a grounding block; you are wasting your time and money.
Quote:
The amp is a RS 15-1108 that is supposed to have an outdoor amp, which I don't have.
You are wasting your time with that, too. The outdoor part is the preamp; the indoor part is only an attenuator and power supply. Even if you had both parts, it wouldn't be the right amp for you. If you must use an amp, it should be one that is resistant to overload.
Quote:
I can get all the channels I want on the RCA converter box but not without moving the antenna a few degrees.
That means that you are on the edge of the "Digital Cliff: with barely enough signal for the weak ones because of the overload from the strong ones that raises the noise floor from spurious signals created by IMD.
Quote:
The strange part is that the direction doesn't correspond with the report. I'm going to use virtual channel numbers for a minute. If I have the antenna pointed at 3,13, and 29, I have to turn it counter clockwise to get 8 and 11. They should be clockwise. Channels 3 and 30 actually have 2 strong points.
I think that is because of the FM interference and WKAS. There is less overload when you turn away from them.
Quote:
Raising the antenna higher decreases the weak signals. This still doesn't make sense unless the roof is acting as a reflector.
It could be a reflection off the roof or it could be it is making the FM signals and WKAS stronger.
Quote:
So, what is an easy way to rotate an antenna without digging it into the ground while rotating?
Use the "Armstrong Rotator." Clamp a ViceGrip wrench to the mast and rotate it by hand. Setting the base of the mast on something hard and holding it in place with a wall bracket or U bolt would help.
Quote:
If I added a second antenna, can I just use a splitter in reverse?
No, you already have enough complications; don't add another one.
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Last edited by rabbit73; 14-Apr-2016 at 8:40 PM.
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Old 14-Apr-2016, 9:39 PM   #31
chris1379
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Thanks. I looked for a ground and didn't find anything close. The fence post wouldn't be very good so I guess I'll have to get a ground rod. On the bright side, I found some additional mast so I could easily go to 30 feet. I would be worried at anything higher because guy wires are not possible here.
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Old 14-Apr-2016, 11:27 PM   #32
rabbit73
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One time I did a test setup with the antenna and preamp connected to a 4-way splitter and then to two converter boxes, two 8-inch monitors, a Sony 22-inch LCD TV, and signal level meter. This was a temporary setup to compare the sensitivity of the tuners using a step attenuator to bring the signals to the digital cliff. The antenna coax was not grounded.

When I touched the coax and the metal strip on the edge of the counter I felt a mild shock. I investigated further and found that what I felt was the sum of the leakage currents from all of those AC operated devices. The leakage current measured about 200 uA; not a dangerous amount but enough to be felt.

I connected a wire only to the grounding pin of a 3-wire plug (no connection to the other pins), connected the other end of the wire to the splitter case, and inserted the plug into a properly wired 3-wire outlet. This connected the coax shield to the house electrical system ground. The leakage current then measured zero.

So, I'm very particular about grounding the coax shield to the house electrical system ground with a grounding block for personal electrical safety AND to reject interference.

Case history:
http://www.digitalhome.ca/forum/81-o...ml#post1457594
http://www.digitalhome.ca/forum/81-o...ml#post1457668
Attached Images
File Type: jpg Simpson229_1.jpg (37.0 KB, 286 views)
File Type: jpg Test Setup.jpg (176.4 KB, 298 views)
Attached Files
File Type: pdf LeakageCurrentTests.pdf (87.7 KB, 247 views)
__________________
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Last edited by rabbit73; 15-Apr-2016 at 12:17 AM.
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Old 15-Apr-2016, 4:30 PM   #33
chris1379
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I don't disagree with you on grounding, as I have a background in electronics and measurement. I just haven't found one yet. As a matter of fact, I found more problems. I did some checking with my multimeter and there is 60 VAC between my PC case and the LCD TV. Both are plugged in to different 3 prong outlets. There is no ground wire on either outlet. This is a very old house.

I'm hoping I will find a cold water pipe just inside the basement by the antenna. Hopefully, that's how the electric service is grounded. I'll ground the coax and mast and then see about the rest.

Last edited by chris1379; 15-Apr-2016 at 5:45 PM.
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Old 15-Apr-2016, 10:40 PM   #34
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Quote:
I have a background in electronics and measurement.
Me, too. Measurements are one of my favorite things to do, as you can see from the signature for my posts.
Quote:
I did some checking with my multimeter and there is 60 VAC between my PC case and the LCD TV.
Maybe you have leakage current. You probably don't have a Simpson 229 Leakage Current Tester, but you can build a simple circuit to make tests.
http://www.repairfaq.org/sam/safety.htm#saftes

Manual
http://www.simpsonelectric.com/image...9-2_manual.pdf
Quote:
there is 60 VAC between my PC case and the LCD TV. Both are plugged in to different 3 prong outlets. There is no ground wire on either outlet.
You have two 3 prong outlets, and neither one has the socket for the grounding pin of a 3-wire plug connected to ground?

Please make some leakage current tests soon.

http://www.mdsr.ecri.org/summary/det...px?doc_id=8285
Attached Images
File Type: jpg Leakage current testing diagram.JPG (66.8 KB, 329 views)
__________________
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Last edited by rabbit73; 15-Apr-2016 at 11:10 PM.
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Old 16-Apr-2016, 6:54 PM   #35
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I just realized that I can't find the answer to one of the questions I had early on. WVAH and WCHS appear to be on the same tower. They have the same ERP. Why does WCHS only have half of the signal strength?
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Old 16-Apr-2016, 8:06 PM   #36
rabbit73
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Good question. I don't know why; the specs look the same.
http://www.rabbitears.info/tvq.php?r...tems&facid=417
http://www.rabbitears.info/tvq.php?r...ms&facid=71280

The only difference I can see is the frequency of the transmitted signal.
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Last edited by rabbit73; 16-Apr-2016 at 8:16 PM.
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Old 16-Apr-2016, 8:37 PM   #37
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The TV Fool report is consistent with my actual reception, too. I wonder if one antenna is higher on the tower or if the different frequencies propagate differently.
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Old 24-Apr-2016, 3:52 AM   #38
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Well, I'm about to give up. I have moved this antenna up, down and even back a few feet. That is about 15 ft. in the picture but I have tried as high as 25 ft. It works better when the antenna is lower than the flue pipe. Some things just don't make sense. When cars go by, the signal changes. WCHS gets lost by lowering it. WOWK and WVAH get lost by raising it. WOWK has a decent signal when it breaks up or cuts out. I'm thinking multipath? Is there anything in the picture that screams "fix me"? If not, what antenna do I need that is reasonably priced?


By the way, I have looked this antenna over a few times and I'm still curious how it works. It looks like an LPDA but I'm not sure. I do know that each of the 3 sets of VHF elements is resonant at 2 frequencies. The first set is a full wave on channel 13 but 1/2 wave around 105 MHz. The third set is 1/2 wave at Channel 2 but a full wave at 108 MHz. It would probably be better for me to have an antenna that is made for UHF and High VHF that is not designed for VHF low at all. There would be less to filter out.
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Last edited by chris1379; 24-Apr-2016 at 7:32 AM.
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Old 24-Apr-2016, 6:56 PM   #39
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Quote:
Originally Posted by chris1379 View Post
Is there anything in the picture that screams "fix me"?
Yes! You need lot more metal in the air and more height to reliably receive the stations shown on the signal report in your first post on this thread. If you are aiming for the stations in the arc from 99 to 108 degrees magnetic, then you need a fair amount of gain for real channel 13 (VHF-Hi) and very high gain for the others (UHF). Even then you may encounter problems with the stations showing negative NM in your report. Some of the others on the board can make better suggestions than me, but if I were in your shoes I would probably try an 8 or 12 element VHF-Hi antenna and a long yagi or 8-bay bowtie for UHF.
Here are a few links to check out:
http://www.mcmelectronics.com/produc...-2475-/30-2475
http://www.mcmelectronics.com/produc...-2476-/30-2476
http://www.mcmelectronics.com/produc...-2370-/30-2370
http://www.mcmelectronics.com/produc...-2430-/30-2430
There are not many choices out there for VHF-Hi antennas, but there are other brands of the UHF antennas you could check out that may have better build quality. You could also look at a combination VHF-Hi/UHF antenna but I think you would be best served with the highest possible gain on UHF that you can get.
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Old 25-Apr-2016, 12:45 AM   #40
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Quote:
When cars go by, the signal changes.
That's normal; you are getting a reflection from the car. It's called dynamic multipath.
Quote:
Is there anything in the picture that screams "fix me"?
Yes, you are geting reflections off metal objects like the gutter, awning, and fence that can interfere with or enhance the direct signals. It's called static multipath.
Quote:
If not, what antenna do I need that is reasonably priced?
There is no sense in trying another antenna yet until you have done the things needed with this antenna like grounding, filters, and another antenna location.

What is your present connection system?

Ant > grounding block > HLSJ > tuner ? You should get WOWK with that.

Once you have that you can try some experiments with an antenna with more gain, another filter, and a preamp for WCHS.

Ant > UVSJ > NF-471 > preamp > grounding block > power inserter > tuner

The antenna would be a UHF antenna with more gain like the 91XG

The UVSJ blocks FM and VHF-High but passes UHF

The NF-471 Notch Filter blocks UHF channels 24-29 to make 26 much weaker to keep the preamp from being overloaded by 26
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Last edited by rabbit73; 25-Apr-2016 at 1:06 AM.
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