Brookville, MD: Reception just went to 0 for no apparent reason - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 7 Old 03-01-2020, 09:23 AM - Thread Starter
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Brookville, MD: Reception just went to 0 for no apparent reason

This is the OTA setup I've had for years with no problems. ChannelMaster 4228 on the roof. Radioshack 15-1170 inline preamp on both ends of the 50' coax from antenna to passive splitter. 3 different coax cables from splitter to 3 different TV's.

Yesterday all 3 TV's stopped getting OTA reception. I checked that the preamp is getting power. I got on the roof, all is connected and intact. My guess is the 1170 just went bad. Can that happen?

My antenna is strong enough to power 1 tv, I need the preamp because of the 3 way splitter. to debug I'm thinking I should bypass the preamp and splitter to see if I get reception on 1 TV. My question on this approach is to I have to remove the other part of the preamp that is on the roof right at the antenna?

Any other advice is appreciated.


Peter

http://www.tvfool.com/?option=com_wr...8e0384013be7ec
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post #2 of 7 Old 03-01-2020, 10:17 AM
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Hello, Peter

Go directly from the antenna to just one TV with one good piece of coax.

If the coax downlead from the preamp will not reach the antenna, you can use an F-81 adapter to join the short coax from the antenna with the coax downlead, but it would be better to use just one good length of coax for this test.



previous thread:
Brookeville, MD: Splitting my OTA signal
https://www.avsforum.com/forum/25-hd...ta-signal.html

If you can not measure it, you can not improve it.
Lord Kelvin, 1883
www.megalithia.com/elect/aerialsite/dttpoorman.html

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post #3 of 7 Old 03-01-2020, 11:58 AM - Thread Starter
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That works fine Antenna -> 1 TV. And it was my mistake before . Now that I got up there and removed both parts of the inline amp, I now see it's Radio Shack 15-1170. I guess I need a new one. With no moving parts, I don't understand how it "broke"

I do have a Channelmaster 0747 amp but I hesitate to use it because there is no power where it would go and it's a big ugly ivory brick. With the radio shack device I was able to cut the power wire, feed it through the wall of the house, splice it back, and plug it in.

Does anyone have an opinion on what is better? an inline with a part at both ends of the long run from antenna or the Channelmaster that has an in/out at the end of the long run?

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post #4 of 7 Old 03-01-2020, 01:23 PM
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Thank you for the report; you did a good test to find out that the Radio Shack preamp isn't working anymore.

You need some amplification when you split the signals for 3 TVs.

The Channel Master 0747 brick is just a power supply/power inserter, not an amp. You would need the preamp part that goes with it at the antenna. When you use a preamp, it comes in two parts: the preamp itself at the antenna and a power supply/power inserter down below inside. The power inserter sends the DC power up to the preamp at the antenna on the same coax that sends the signals down.

You have two choices: You can buy another preamp and put the amplifier near the antenna which will amplify the signals before they come down the coax to the power inserter and the splitter.

Your other choice is to use a distribution amp down below before splitting. You can use a Channel Master 3410 and then your 3-way splitter.

After looking at your TVFool report, I'm surprised that you need some amplification before splitting because your signals are very strong, so I favor the distribution amp solution. Perhaps your signals are not as strong as listed on the report because of objects in the signal path like trees or buildings.
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post #5 of 7 Old 03-01-2020, 02:15 PM - Thread Starter
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Thanks.

I used a 50' cable from antenna to splitter. WHo knows how long the 3 runs to the 3 TV's are. I ran them when we had the addition put on in 2008. 2 of them go pretty far like 25-30' each.
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post #6 of 7 Old 03-01-2020, 03:27 PM
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Quote:
Originally Posted by madeucre View Post
Thanks.

I used a 50' cable from antenna to splitter. WHo knows how long the 3 runs to the 3 TV's are. I ran them when we had the addition put on in 2008. 2 of them go pretty far like 25-30' each.
When you made the test of removing the inline anp and connecting the antenna directly to one TV and had good reception, did you also try connecting the antenna to the splitter to see how the signals would be on all 3 TVs without the help of the inline amp?







When you had the inline amp installed, did you insert the DC Block?

I used an earlier version of the RS In-Line amp, the 15-1115 (No. 9), as a preamp for my signal level meter. It failed, so I replaced it with a CM 3410, which has a gain of 15 dB.



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If you can not measure it, you can not improve it.
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www.megalithia.com/elect/aerialsite/dttpoorman.html

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post #7 of 7 Old 03-01-2020, 06:34 PM
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Quote:
Originally Posted by madeucre View Post
My antenna is strong enough to power 1 tv, I need the preamp because of the 3 way splitter. to debug I'm thinking I should bypass the preamp and splitter to see if I get reception on 1 TV. My question on this approach is to I have to remove the other part of the preamp that is on the roof right at the antenna?

Any other advice is appreciated.

Peter

http://www.tvfool.com/?option=com_wr...8e0384013be7ec
Your TVfool link doesn't work, but based on your report image, here is a report from rabbitears.info:

https://www.rabbitears.info/searchma...study_id=65293

After looking at your reports and your previous thread
Brookeville, MD: Splitting my OTA signal
https://www.avsforum.com/forum/25-hd...ta-signal.html

I don't understand why you would need an amp; your signals are so strong. Which way is your antenna aimed?

Would you be willing to tell me your address in a forum PM (Private Message) for privacy, so that I can look at a satellite view of your location?

If you can not measure it, you can not improve it.
Lord Kelvin, 1883
www.megalithia.com/elect/aerialsite/dttpoorman.html
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