Any suggestions on a low-loss splitter? (1 Viewer)

comfortably_numb

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I recently discovered that my RCA VH240R distribution amp was causing noise on most of my channels, resulting in signal loss. I believe this is because the signal is already being amplified by the preamp on the antenna mast. Once I removed the distribution amp, signal strength doubled. The problem is, I still need to split the feed three ways: to my Hopper 3, to my HD Homerun, and to a bedroom TV. Do all passive splitters have a 3.5 dB loss?
 

boba

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I recently discovered that my RCA VH240R distribution amp was causing noise on most of my channels, resulting in signal loss. I believe this is because the signal is already being amplified by the preamp on the antenna mast. Once I removed the distribution amp, signal strength doubled. The problem is, I still need to split the feed three ways: to my Hopper 3, to my HD Homerun, and to a bedroom TV. Do all passive splitters have a 3.5 dB loss?
The theoretical loss is 3.5dB you can measure the actual loss and will find variances but not drastic differences.. Two way splitters have a 3.5dB loss 3 way splitters have 3.5dB on one leg and 7dB on 2 legs.
 
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waylew

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Do all passive splitters have a 3.5 dB loss?
A 2 way split will -3.5 on each leg,a 3 way splitter will have one -3.5 and two -7,a 4 way would be -7 on all ports and so on.
You could use taps which come in a wide range of -db's.
Or just try padding down the signal going in to the distro,you can buy attenuators in various -db's,or just use splitters.
edit,boba beat me,buy I type slow :biggrin
 
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harshness

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There are three-way splitters that are 5.5dB on all outputs.

Splitters are voltage dividers so you're going to see less signal (along with the insertion losses of connectors) when you use them.

The signal quality won't be dropped by that much as the noise level will go down along with the good signal.

Using dB is kind of like using a sliderule: everything is in logarithms. 3.5dB loss leaves you with 44.7% of the original signal. 7db loss is 20% of the input signal.
 

primestar31

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I recently discovered that my RCA VH240R distribution amp was causing noise on most of my channels, resulting in signal loss. I believe this is because the signal is already being amplified by the preamp on the antenna mast. Once I removed the distribution amp, signal strength doubled. The problem is, I still need to split the feed three ways: to my Hopper 3, to my HD Homerun, and to a bedroom TV. Do all passive splitters have a 3.5 dB loss?

I use this one, and it's outstanding: Amazon product
Note: If you can't see the link from Amazon I've posted above, temp disable your ad blocker, and do a refresh...
 

harshness

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How is it passive if it’s amplifying the signal on all 4 legs?
A passive device wouldn't have a 12-15vdc input on it.
Won’t this just have the same effect as the VH240R?
Probably. Then again, it may have a much lower noise contribution.

I've used this balanced 3-way:

Amazon product
Amazon also offers a balanced 3-way two pack of a different brand for $8.99. The unbalanced ones are cheaper but they really whack the signal on the 7dB legs.
 

primestar31

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How is it passive if it’s amplifying the signal on all 4 legs? Won’t this just have the same effect as the VH240R?

It's not passive, but it's low noise and basically only amps it enough to account for the losses you'd have in a passive splitter. It's one of the best of it's kind out there.

I really doubt it'll have the same noise problems you saw with the VH240R.
 
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comfortably_numb

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It's not passive, but it's low noise and basically only amps it enough to account for the losses you'd have in a passive splitter. It's one of the best of it's kind out there.

I really doubt it'll have the same noise problems you saw with the VH240R.

Ok, I’ll give it a try. Thanks for the tip
 

comfortably_numb

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The PCT drop amp arrived from Amazon yesterday. I tried it out and unfortunately, it had the same exact effect as the RCA VH240R. It amplified the noise but lowered signal quality. So, it's getting returned. Was a nice experiment, though. ;)
 

harshness

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Since there is already a pre-amp involved you may be blowing things out with a distribution amp.

Then again, maybe it is time to concede that digital killed the DXing star. :oldno
 

comfortably_numb

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Since there is already a pre-amp involved you may be blowing things out with a distribution amp.

Then again, maybe it is time to concede that digital killed the DXing star. :oldno

My goal on this project isn’t so much as good DX’ing but better signal quality overall. Bought a Rocketfish passive 3-way splitter at Best Buy this afternoon; will see how it works
 

waylew

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Did you try knocking the signal down before going into the distro amp?You can use your 3 way and have a choice of 3.5 or 7 db cut,if it's a typical 3 way splitter.
Also how is the quality of the signal just coming out of the pre amp?
 

comfortably_numb

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Did you try knocking the signal down before going into the distro amp?You can use your 3 way and have a choice of 3.5 or 7 db cut,if it's a typical 3 way splitter.
Also how is the quality of the signal just coming out of the pre amp?

Signal strength and quality coming out of the preamp is great. It’s when I add a powered distribution amp that things get messy.
 

boba

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Did you try knocking the signal down before going into the distro amp?You can use your 3 way and have a choice of 3.5 or 7 db cut,if it's a typical 3 way splitter.
Also how is the quality of the signal just coming out of the pre amp?
Three way splitter has 7db of loss on 2 legs and 3.5db loss on the remaining leg, so your only choice is how much loss you pass to the TV. The amplified output of the preamp may be overdriving the front end of the distribution amp.
 
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Foxbat

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The amplified output of the preamp may be overdriving the front end of the distribution amp.
If you have a TV or FM station that is nearby, that signal could be high enough that adding the distribution amp causes clipping in the DA, generating harmonics that effectively wipe out the weaker signals of the distant TV stations. With digital, It isn't signal strength as much as signal quality and SNR. DA clipping equals more noise.

It would be nice if ATSC Receivers didn't label their bar graphs as "Signal Strength" but "Quality". You can have a strong signal, but if it isn't clean, it won't be decodable. Quality over Quantity.
 

comfortably_numb

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If you have a TV or FM station that is nearby, that signal could be high enough that adding the distribution amp causes clipping in the DA, generating harmonics that effectively wipe out the weaker signals of the distant TV stations. With digital, It isn't signal strength as much as signal quality and SNR. DA clipping equals more noise.

It would be nice if ATSC Receivers didn't label their bar graphs as "Signal Strength" but "Quality". You can have a strong signal, but if it isn't clean, it won't be decodable. Quality over Quantity.

My meter shows signal strength, signal quality, and symbol quality. When adding the powered distribution amp, signal strength increases while signal quality decreases. There aren’t any FM transmitters in the area, but there is one LP tv station within LOS. I think it’s like boba said: the signal from the preamp overloads the input on the distro amp.
 

harshness

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My goal on this project isn’t so much as good DX’ing but better signal quality overall.
When your metrics involve the signal quality on stations too many miles away, you're kind of fooling yourself.

Overall signal strength when you've got such a variance can be too much for AGC to accommodate for. Amps don't look at each frequency individually, the look at the whole band and trying to combine faint signals with booming locals is a recipe for compromise.
 

primestar31

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The PCT drop amp arrived from Amazon yesterday. I tried it out and unfortunately, it had the same exact effect as the RCA VH240R. It amplified the noise but lowered signal quality. So, it's getting returned. Was a nice experiment, though. ;)

Sorry about that. Amazon is real good at returns, so you can go into your account there, and start one real easy on that.

On the other hand, if you have some 3db attenuators laying around, you can try using them on the outputs of the PCT amp, and see if that makes a difference. They use to come with the dish receivers to be used if needed for the UHF remote.

Even if you only have one, you could try that on the INPUT, and see if it brings up the signal levels. I know it sounds counter-intuitive, but in certain cases it can work.

Whoops, guess I should have read all the way through the extra posts before posting. I see others have already mentioned the above. Yes, you can use a splitter as an attenuator in a pinch
 
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