Missing OTA Channels?

[Lone Gunman]

Sounds like a balun, but most I’ve seen are round, about as thick as a cigar and half as long.

Yeah, I've been looking for something that is similar to what is on it now but haven't seen anything close at this point.

Say, is there another name for those things besides balun?

Thanks all!!!

 

[comfortably_numb]

Yeah, I've been looking for something that is similar to what is on it now but haven't seen anything close at this point.

Say, is there another name for those things besides balun?

Thanks all!!!

Matching transformer?

 

[harshness]

Home Depot sells a Channel Master Balun/Matching Transformer for pretty cheap. Amazon carries many options.

Electronic component shops usually carry one.

The goal is to convert from the 300 ohm impedance that most outdoor antennas feature to the ~75 ohm impedance of TV cable and tuners demand.

 

[waylew]

Yeah, I've been looking for something that is similar to what is on it now but haven't seen anything close at this point.

Say, is there another name for those things besides balun?

Thanks all!!!

Open up the black box and make sure everything is clean,no corrosion, and tight,loose screws.It's likely just a circuit board with copper traces on it.
A number of 8 bays I got came with the balun assembled wrong or with loose screws.Not the brand you have,but similar.
You might want to take the antenna down and work on it in the shop,lots of little bits to lose.

 

[Lone Gunman]

Purchased some new parts, matching transformer, 2 way splitter and a 3 way splitter, both of which are Rocketfish brand name for the system and I'm contemplating replacing the coax while I'm at it just to eliminate that as the problem.

I do have a question though, does anyone know if a Rocketfish 3 way splitter is balanced or not? I've been looking online but haven' t seen any info on that?

Is there a way to test these splitters with a regular volt/ohm meter? Reason I ask is because some of them show open and others show a reading?

Also looking for suggestions on a distribution amp since I seem to have had a fair amount of signal loss to the other two TVs I previously had connected to this system in other rooms.

Looks like it's going to be a week or two before I can get up on the roof to work on that end. We had snow last weekend and we're going to get snow again tonight?? DAYUMNIT, I HATE WINTER!!

 

[navychop]

Yep. Looks like no spring this year. Just winter, BAM, summer.

 

[comfortably_numb]

Purchased some new parts, matching transformer, 2 way splitter and a 3 way splitter, both of which are Rocketfish brand name for the system and I'm contemplating replacing the coax while I'm at it just to eliminate that as the problem.

I do have a question though, does anyone know if a Rocketfish 3 way splitter is balanced or not? I've been looking online but haven' t seen any info on that?

Is there a way to test these splitters with a regular volt/ohm meter? Reason I ask is because some of them show open and others show a reading?

Also looking for suggestions on a distribution amp since I seem to have had a fair amount of signal loss to the other two TVs I previously had connected to this system in other rooms.

Looks like it's going to be a week or two before I can get up on the roof to work on that end. We had snow last weekend and we're going to get snow again tonight?? DAYUMNIT, I HATE WINTER!!

What do you mean by balanced? One output is -3.5 dB and the other two would be -7 dB

 

[harshness]

I do have a question though, does anyone know if a Rocketfish 3 way splitter is balanced or not?

That depends on what you mean by "balanced". If you want to know if all three outputs have equal signal loss numbers, you're going to be disappointed as Rocketfish hasn't seen fit to make that information available nor do they number the outputs.

Is there a way to test these splitters with a regular volt/ohm meter?

No. The impedance matching is done with chokes and/or capacitors so a typical VOM won't help you there.

 

[comfortably_numb]

That depends on what you mean by "balanced". If you want to know if all three outputs have equal signal loss numbers, you're going to be disappointed as Rocketfish hasn't seen fit to make that information available nor do they number the outputs.No. The impedance matching is done with chokes and/or capacitors so a typical VOM won't help you there.

On a 3-way splitter, what I do is hook my HD Homerun device up to each port one at a time, then measure signal strength and quality on each one. It’s usually pretty easy to tell which output is the -3.5 dB leg and then you know the other 2 are -7.

 

[harshness]

One output is -3.5 dB and the other two would be -7 dB

While that's a safe assumption, there are three-way splitters that have the same loss on all outputs. I have one of these:

 

[comfortably_numb]

I have that Rocketfish 3-way splitter. I will test it out afterwhile and post my results here.

 

[Lone Gunman]

So how about the distribution amp? Any particular brand that is better than others? From what I've seen, some are made where you can actually replace a multiport splitter with them, yes/no?

 

[harshness]

On a 3-way splitter, what I do is hook my HD Homerun device up to each port one at a time, then measure signal strength and quality on each one..

If the tuner has Automatic Gain Control (AGC, as most do), signal strength could be misleading depending on whether or not AGC is active. I suppose that if the tuner reports its numbers pre-AGC, then it would be a valid measure. I don't expect that's how it works at this level of sophistication though I could certainly be wrong.

 

[comfortably_numb]

So how about the distribution amp? Any particular brand that is better than others? From what I've seen, some are made where you can actually replace a multiport splitter with them, yes/no?

My experience has been that distro amps actually reduce signal quality if there is a preamp in the mix. If you don’t use a preamp, you can replace your splitter with a distro amp. Most are +10 dB on each leg.

RCA VH240R Four-Way Video Signal Amplifier & Splitter, 5-42MHz | eBay

 

[harshness]

So how about the distribution amp?

One step at a time. If the splitter doesn't get you where you need to go, then you start worrying about how you're going to replace it. With less than five splits, DAs are pretty drastic measure and the problem might better be addressed with a more powerful preamp.

 

[harshness]

If you don’t use a preamp, you can replace your splitter with a distro amp.

I submit that the best DA isn't going to give as good a result as a fair to midlands preamp. DAs are designed to take a good signal and split it many ways. If the signal isn't good to begin with, neither are its multiples.

A preamp gets the best possible signal (near the antenna) and boosts it down the line. A DA gets its signal after the downlead has had its pound of flesh.

 

[Lone Gunman]

I submit that the best DA isn't going to give as good a result as a fair to midlands preamp. DAs are designed to take a good signal and split it many ways. If the signal isn't good to begin with, neither are its multiples.

A preamp gets the best possible signal (near the antenna) and boosts it down the line. A DA gets its signal after the downlead has had its pound of flesh.

Preamps go outside at the antenna and I don't want to go there, ie, I'm too damn old to be climbing a 20ft ladder to get on the roof so the less equipment I have up there to hork up, the better IMHO.

As far as the distribution amp goes, I have a fair amount of signal loss to the 2 other rooms because the TVs in those rooms won't scan in squat now. Used to be that they'd get enough channels to get by but now they get none to 3 or 4 whereas the TV next to where the cable comes into the house will currently get 19 when connected directly to that TV and got 29 before this problem came up. I figure the distribution amp will boost the signal to those other rooms to compensate for the loss for the cable run and I can mount it on the wall next to the cable entrance behind the TV in that room.

 

[comfortably_numb]

As far as the distribution amp goes, I have a fair amount of signal loss to the 2 other rooms because the TVs in those rooms won't scan in squat now. Used to be that they'd get enough channels to get by but now they get none to 3 or 4 whereas the TV next to where the cable comes into the house will currently get 19 when connected directly to that TV and got 29 before this problem came up. I figure the distribution amp will boost the signal to those other rooms to compensate for the loss for the cable run and I can mount it on the wall next to the cable entrance behind the TV in that room.

I think the distro amp sounds reasonable in your situation. Check out that VH240R. It's a good one.

As for as the Rocketfish 3-port splitter, I tested it and all legs appear to have the same level of loss ("balanced" as you say). So, I'm assuming 5.5 dB loss on all 3 legs.

For comparison, I tested it against my 2-port splitter, which says on the sticker -3.5 dB on both legs. The 3-port signal level was just slightly lower than the 2-port, but consistent across all 3 legs.

 

[Lone Gunman]

OK so I got to ask, what is the difference between the RCA VH140 and the RCA VH240R besides the "wall wart" on the 240R?

 

[comfortably_numb]

OK so I got to ask, what is the difference between the RCA VH140 and the RCA VH240R besides the "wall wart" on the 240R?

Nothing really, the 240R is just a newer version of the 140