broken antenna question.

[carry2018]

I'm surprised that you manage to receive any channels at all using a discone.
Did you notice that your scanner listening also got worse, or if that is still as it was before the loss of TV signal, then it might be something wrong with the splitter you are using. Try to switch outputs or coaxes from splitter to TV./Ubbe

What splitter would you suggest if I were to split it off to my scanner. I can't even find the one I was using and forgot what it was. I would guess 25 to 2000 mhz if that exists.

Thanks

 

[Ubbe]

A passive splitter drops the signal to half. Don't know what type of connectors you have. When you mention BNC and not F for the adaptor I hope you still use RG6 coax and not RG58 to receive UHF signals.

If you plan to do some scanner and SDR listening then go for an antenna amplifier at the antenna and a 1-6 splitter to reduce the signal 10dB to not cause overload. The Antennas Direct PA18 seems like a reasonable amplifier with 15dB gain and 1.6dB noise figure. An even better amplifier are https://www.ebay.com/itm/Low-Noise-...SB-Power-ESD-protection-Bias-Tee/283270481375 or https://www.amazon.com/RTL-SDR-Blog-Wideband-Amplifier-Powered/dp/B07G14Q6XX/ used with a 5 volt power inserter that sends 5 volt up the coax. You'll need additional adaptors or pigtails with those to make it work.

/Ubbe

 

[rfradioconsult]

If you are using this antenna for TV reception almost exclusively why not replace it with a proper directional UHF/VHF TV antenna? You will gain better reception with correct polarity and directional gain. Also replace the coax with a good quality quad-shield RG-6 cable with the correct connectors.

 

[majoco]

Infact maybe you will increase the signal if you remove all bottom elements

Umm, err - no. If they were not necessary, why would the manufacturer put them on there?

The 'cone' element length determines the low frequency response.

See...

https://www.electronics-notes.com/articles/antennas-propagation/discone-antenna/discone-basics.php

 

[Ubbe]

Umm, err - no. If they were not necessary, why would the manufacturer put them on there?

Cause he is receiving horisontal polarised signals with a vertical polarised antenna. If it where a yagi antenna it would be something like a 20dB drop in signal strenght. Removing the bottom elements will convert it from a discone to some sort of multielement horisontal antenna by just using the top elements. If he wants to combine and also use it for scanner listening he could screw back those bottom elements but his televions signals would suffer.

/Ubbe

 

[prcguy]

If you remove the bottom cone I believe the Discone would still be a vertical pol antenna. The reason is when you have multiple horizontal elements of the same length heading out from a common point in different directions, they cancel radiation. The resulting antenna would be more of a super short vertical element with a capacity hat.

Cause he is receiving horisontal polarised signals with a vertical polarised antenna. If it where a yagi antenna it would be something like a 20dB drop in signal strenght. Removing the bottom elements will convert it from a discone to some sort of multielement horisontal antenna by just using the top elements. If he wants to combine and also use it for scanner listening he could screw back those bottom elements but his televions signals would suffer.

/Ubbe

 

[picscan]

You could goto the hardware store and get some allthread the same size.

 

[n5ims]

Two suggestions to resolve your issues.

1) Use a stainless steel rod (as was suggested above). They aren't hard to find (your local Home Depot for example --> Stainless Steel - Metal Sheets & Rods - Hardware - The Home Depot), but you'll need to know the correct size (you may want to simply remove a complete one and bring it with you and ask the sales folks "I need a stainless steel rod to replace this". You could also bring the broken one but you'll need both parts, the rod and the part that screws into the antenna so they can match the screw size. If you can't get an "all thread" rod in the correct size, you can get a solid rod and a "tap and dye" to thread it yourself. I recommend that since you'll be working on the antenna anyway, you get enough rods to replace them all so you won't have to do the task again next time a butterfly lands on one of those cheaply made RS element rods. This is what my RS Discone looked like after an ice storm. Most elements (including the top whip and coil) were intact prior to the storm.

2) One or more of your TV stations may have changed frequency in preparation for the latest update to how digital TV signals are being transmitted in the US. Often this is done in stages so you may need to rescan fairly often to keep up with the various stations making the necessary changes. Also note that during this change more stations will move to VHF (channels 2 - 13), unlike the previous digital TV migration when most stations moved to UHF channels for their RF signal (they nearly all kept their old channel number for the display even though they no longer actually transmit on their old channel frequency (e.g. what the station that displays 5-1 since their analog signal was transmitted on channel 5 may have transmitted on UHF channel 32 after going digital).

This link from the FCC web site has some details --> Broadcast TV Transition: What to Watch For

Some local TV stations in cities across the U.S. will be changing their over-the-air broadcast frequencies between now and July 2020.
People who watch free over-the-air television with an antenna will need to rescan their TV set each time a station moves to continue receiving the local channel. It's the same scan that you did to find your local channels when you set up your TV or converter box for the first time. Except in rare circumstances, no new equipment or services are required.

 

[cmdrwill]

TVfool.com should have TV channel information for your city. And YES they are still transmitted horizontally.

 

[carry2018]

Two suggestions to resolve your issues.

1) Use a stainless steel rod (as was suggested above). They aren't hard to find (your local Home Depot for example --> Stainless Steel - Metal Sheets & Rods - Hardware - The Home Depot), but you'll need to know the correct size (you may want to simply remove a complete one and bring it with you and ask the sales folks "I need a stainless steel rod to replace this". You could also bring the broken one but you'll need both parts, the rod and the part that screws into the antenna so they can match the screw size. If you can't get an "all thread" rod in the correct size, you can get a solid rod and a "tap and dye" to thread it yourself. I recommend that since you'll be working on the antenna anyway, you get enough rods to replace them all so you won't have to do the task again next time a butterfly lands on one of those cheaply made RS element rods. This is what my RS Discone looked like after an ice storm. Most elements (including the top whip and coil) were intact prior to the storm. View attachment 68337

2) One or more of your TV stations may have changed frequency in preparation for the latest update to how digital TV signals are being transmitted in the US. Often this is done in stages so you may need to rescan fairly often to keep up with the various stations making the necessary changes. Also note that during this change more stations will move to VHF (channels 2 - 13), unlike the previous digital TV migration when most stations moved to UHF channels for their RF signal (they nearly all kept their old channel number for the display even though they no longer actually transmit on their old channel frequency (e.g. what the station that displays 5-1 since their analog signal was transmitted on channel 5 may have transmitted on UHF channel 32 after going digital).

This link from the FCC web site has some details --> Broadcast TV Transition: What to Watch For

Hi again. Well, I survived our ice and snow storms, the ant is in one piece and still standing. I have a few issues that need to be taken care of before going at this antenna issue of fade out digital OTA tv. One, we need the electricians to come back and finish the job of installing the new power panel. Lots of the house is in ground fault conditions, no proper ground continuation. That will be corrected very soon.

Due to this ant being installed on roof edge, it itself doesn't seem to have any grounding. Would it help anyways if I run copper straight from the ant to a ground rod and where on the ant should that be connected?

And that picture is an exact match to my discone.