Signal Amplifiers (Amps, Preamps, Distro Amps) - See Chart in Post #1 - Page 144 - Canadian TV, Computing and Home Theatre Forums

paulbelanger · 2010-09-30, 06:12 PM

Stampeder,

I tried attenuating the input signal as you suggested, using a high quality 3.5dB splitter (one from Rogers).

My setup currently looks like this:

Terk -> CM7778 pre-amp -> CM7778 power -> 3.5dB splitter (one output terminated) -> Leviton 1x6 splitter -> TVs

With this setup I'm getting 77% for CBC, 72% for SRC, 60% for SunTV and nothing for Omni1 and CityTV. So CBC stayed about the same (not surprising since it's so powerful), but the rest of them all went down compared to when I just had the cheap Terk distribution amp.

Is it possible I got a bum CM7778, or should I try attenuating its signal even further? Stupid question maybe, but should the CM7778's power unit come before or after the Leviton splitter?

I guess I'm going to go buy some more attenuators, or maybe remove the CM7778 and try that Leviton distribution amp like I said earlier. I just hate going in the attic.

elmsley · 2010-10-04, 12:22 PM

I checked out HD, FutureShop, Source for amps and these things don't look like they've been updated since they were invented from their look and color styles. (That's not my question, just an observation.)

1. Anyways, when a 4-way says 10db gain, does that mean +2.5db per output or 10db per output?

2. Also, not sure exactly what shops carry CM Amps in my area. I can go online, but returning them is a pain. I want to do some experimenting with different configs for my setup.

3. Does an amp always require a power source? I got this cheap inline amp (with no plug) and I can't tell if it's broken or if maybe my signal isn't strong / (stable ?) enough for it to work. It said 30db gain but I think I just wasted my $6.

ota_canuck · 2010-10-04, 12:44 PM

Do you have a model# and manufacturer name for that inline amp/booster? It should also show a frequency range. I think they are only helpful with satellite and cable signals.

ProjectSHO89 · 2010-10-04, 07:10 PM

Quote:

1. Anyways, when a 4-way says 10db gain, does that mean +2.5db per output or 10db per output?

It means that EACH output is expected to be 10 dB more powerful than the input. A four-way distribution amp with a stated 10 dB of gain would be expected to be the combination of a 17 dB amplifier module with a 4-port splitter (7 dB insertion loss) built into the same shell.

Quote:

3. Does an amp always require a power source?

Yes, always.

flavoie · 2010-10-04, 07:17 PM

paulbelanger, depends how long of a run you have.
With no splitters and a short run, i usually add 12dB of attenuation after my Kitz preamp and it works better. You must have a longer run, so you'd be between 3-12dB... 2 x 6dB attenuators should be all you need, less if you use splitters to do the same job.

ota_canuck · 2010-10-04, 09:32 PM

Quote:

Stupid question maybe, but should the CM7778's power unit come before or after the Leviton splitter?

It is not recommended to have anything in the downlead cable between the power supply and the mast preamp unit.

ProjectSHO89 · 2010-10-05, 08:02 AM

Quote:

It is not recommended to have anything in the downlead cable between the power supply and the mast preamp unit.

It is completely permissible to have a splitter with "DC PASS" (select the correct port!) between a power inserter and its preamplifier module. Perhaps Channelmaster recommends against such a splitter location since their CM32xx line doesn't offer the DC PASS function....

HWP · 2010-10-05, 09:50 AM

Hello,

If I'm installing a 7778 or 7777 and I want to have the aparatus properly grounded, the electrical source of my pre-amp will be inside. Before that though, ouside on the wall the RG6 coax cable is going to have been cut as it passes through the grounding block.

Do all of these grounding blocks come with DC pass-through?

stampeder · 2010-10-05, 12:57 PM

HWP and all, see the Grounding thread over in the Home Theatre Design, Construction and Setup forum:

Grounding Info & Standards: OTA/Dish/CATV/Telecom

Everything you need to know about Grounding is already in there.

Grounding blocks allow DC Power Pass.

byebye_cable · 2010-10-05, 09:26 PM

Thinking about getting another pre-amp. Are the RC ones still the reigning champs?

Jase88 · 2010-10-05, 09:42 PM

In terms of low noise, yes I believe RC is likely the best. Though I'm not too sure how they hold up to static buildup due to impending storm activity.

Fortunately, if you go with RC, the company appears to support their product exceptionally well.

PanaMark · 2010-10-06, 05:59 AM

I just got around to putting my RC preamp back up on the mast (took all of 5 minutes). Dang this little amp does help for the fringe signals and is pretty tolerable towards local transmitter signals.
In the past two days of having it back up near the mast I have been receiving three channels from Erie Pa (90 miles) relatively solid most of the day.
With my KitzTech I would lose them from 8AM to 6PM.

@Jase
When I was putting the amp back up I took a look at the balun on my XG91 and I don't remember doing this, but I had already covered the hole in the balun (must have done this during the install).

Research Communications does have excellent customer service and quick turn around for warranty issues. I highly recommend if you are serious about your OTA system.

Mark

byebye_cable · 2010-10-06, 08:48 AM

I guess I'll get one. I also have a Kitztech, but I bought mine before they came out with their new .4 db low noise preamp. I have the Kitztech 1db noise preamp - works quite well.

Wondering if anyone compared the "new" Kitztech .4 noise preamp with the .4 noise preamps from RC. I suspect the RC is better, but that's pure guessing on my part. PanaMark, which type of Kitztek are you comparing to?

Edit: Looks like the RC1962 is the one, but it includes VHF-LO. If there's a better choice let me know. Alot of the weaker stations I'm interested it are VHF-HI.

intravino · 2010-10-06, 12:19 PM

I tested a RC preamp last year for Ch13 fringe setup here in the Richelieu Valley.

I can't really say it was better then the Kitz at my location. I did not test every model they sell.

They only thing I can say so sure it's very very sensitive to static but the Kitz has the same problem.

I'm using my CM7777 for my main setup and it's been on for two years without any problems.

My Kitz is connected to a Modified CM4221HD that I turn-on once a week.

byebye_cable · 2010-10-06, 03:55 PM

Quote:

Originally Posted by intravino

My Kitz is connected to a Modified CM4221HD that I turn-on once a week.

What do you mean by that - you "reboot" the Kitz once a week?

Also - how does this senstivity to static appear? I've never noticed an issue with my Kitz, then again, not sure what I'd be looking for.

2010-10-04, 12:22 PM	#2147
elmsley Join Date: Aug 2010 Location: Markham @ Major Mackenzie Posts: 30	Amp spec questions I checked out HD, FutureShop, Source for amps and these things don't look like they've been updated since they were invented from their look and color styles. (That's not my question, just an observation.) 1. Anyways, when a 4-way says 10db gain, does that mean +2.5db per output or 10db per output? 2. Also, not sure exactly what shops carry CM Amps in my area. I can go online, but returning them is a pain. I want to do some experimenting with different configs for my setup. 3. Does an amp always require a power source? I got this cheap inline amp (with no plug) and I can't tell if it's broken or if maybe my signal isn't strong / (stable ?) enough for it to work. It said 30db gain but I think I just wasted my $6.

2010-10-04, 12:44 PM	#2148
ota_canuck Veteran Join Date: Mar 2009 Location: Dunnville, Ontario on the Grand River, North shore Lake Erie Posts: 2,405	Do you have a model# and manufacturer name for that inline amp/booster? It should also show a frequency range. I think they are only helpful with satellite and cable signals. __________________ 3D SSH III with ZZ4 refl. http://imageshack.us/user/jmsdigital

2010-10-05, 09:50 AM	#2153
HWP Join Date: May 2010 Location: Toronto, East York (Greenwood & Mortimer) Posts: 1,143	mast-mounted pre-amps & grounding blocks Hello, If I'm installing a 7778 or 7777 and I want to have the aparatus properly grounded, the electrical source of my pre-amp will be inside. Before that though, ouside on the wall the RG6 coax cable is going to have been cut as it passes through the grounding block. Do all of these grounding blocks come with DC pass-through? __________________ OTA, HD7697P, CM7778, Rotator, CM3218, TiVo, HDHomeRun Apple TV, Netflix, Teksavvy, Unblock-us, Wind, MagicJack

2010-10-05, 09:42 PM	#2156
Jase88 Moderator Join Date: Jan 2009 Location: Kitchener, ON Posts: 4,105	In terms of low noise, yes I believe RC is likely the best. Though I'm not too sure how they hold up to static buildup due to impending storm activity. Fortunately, if you go with RC, the company appears to support their product exceptionally well. __________________ DMX 68' tower, HyGain HAM 5 rotator, Antennas Direct 91-XG & C5, Channel Master 7777 preamp, Siemens surge protection

2010-10-06, 05:59 AM	#2157
PanaMark Join Date: Jan 2009 Location: London, Ontario Posts: 818	I just got around to putting my RC preamp back up on the mast (took all of 5 minutes). Dang this little amp does help for the fringe signals and is pretty tolerable towards local transmitter signals. In the past two days of having it back up near the mast I have been receiving three channels from Erie Pa (90 miles) relatively solid most of the day. With my KitzTech I would lose them from 8AM to 6PM. @Jase When I was putting the amp back up I took a look at the balun on my XG91 and I don't remember doing this, but I had already covered the hole in the balun (must have done this during the install). Research Communications does have excellent customer service and quick turn around for warranty issues. I highly recommend if you are serious about your OTA system. Mark __________________ roof mounted 35ft UHF Antennas Direct XG91, VHF Delhi VIP 302SR, RC 6292, Tii Coaxial Lightning Surge Protection

2010-09-30, 06:12 PM	#2146
paulbelanger Join Date: Sep 2010 Location: Kanata North (Beaverbrook) Posts: 52	Stampeder, I tried attenuating the input signal as you suggested, using a high quality 3.5dB splitter (one from Rogers). My setup currently looks like this: Terk -> CM7778 pre-amp -> CM7778 power -> 3.5dB splitter (one output terminated) -> Leviton 1x6 splitter -> TVs With this setup I'm getting 77% for CBC, 72% for SRC, 60% for SunTV and nothing for Omni1 and CityTV. So CBC stayed about the same (not surprising since it's so powerful), but the rest of them all went down compared to when I just had the cheap Terk distribution amp. Is it possible I got a bum CM7778, or should I try attenuating its signal even further? Stupid question maybe, but should the CM7778's power unit come before or after the Leviton splitter? I guess I'm going to go buy some more attenuators, or maybe remove the CM7778 and try that Leviton distribution amp like I said earlier. I just hate going in the attic.

2010-10-04, 07:17 PM	#2150
flavoie Join Date: May 2007 Location: Orleans, ON Posts: 1,236	paulbelanger, depends how long of a run you have. With no splitters and a short run, i usually add 12dB of attenuation after my Kitz preamp and it works better. You must have a longer run, so you'd be between 3-12dB... 2 x 6dB attenuators should be all you need, less if you use splitters to do the same job.

2010-10-05, 12:57 PM	#2154
stampeder OTA Forum Moderator Join Date: Jan 2005 Location: North Delta, BC (96Av x 116St) Posts: 23,338	HWP and all, see the Grounding thread over in the Home Theatre Design, Construction and Setup forum: Grounding Info & Standards: OTA/Dish/CATV/Telecom Everything you need to know about Grounding is already in there. Grounding blocks allow DC Power Pass.

2010-10-05, 09:26 PM	#2155
byebye_cable Join Date: Nov 2009 Location: Toronto Posts: 434	Thinking about getting another pre-amp. Are the RC ones still the reigning champs?

2010-10-06, 08:48 AM	#2158
byebye_cable Join Date: Nov 2009 Location: Toronto Posts: 434	I guess I'll get one. I also have a Kitztech, but I bought mine before they came out with their new .4 db low noise preamp. I have the Kitztech 1db noise preamp - works quite well. Wondering if anyone compared the "new" Kitztech .4 noise preamp with the .4 noise preamps from RC. I suspect the RC is better, but that's pure guessing on my part. PanaMark, which type of Kitztek are you comparing to? Edit: Looks like the RC1962 is the one, but it includes VHF-LO. If there's a better choice let me know. Alot of the weaker stations I'm interested it are VHF-HI.

2010-10-06, 12:19 PM	#2159
intravino Join Date: Jan 2008 Location: Beloeil Posts: 585	I tested a RC preamp last year for Ch13 fringe setup here in the Richelieu Valley. I can't really say it was better then the Kitz at my location. I did not test every model they sell. They only thing I can say so sure it's very very sensitive to static but the Kitz has the same problem. I'm using my CM7777 for my main setup and it's been on for two years without any problems. My Kitz is connected to a Modified CM4221HD that I turn-on once a week.

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