: Signal Amplifiers (Amps, Preamps, Distro Amps)



tjones357
2010-01-27, 07:22 AM
Hi,
I put on an Amp. the other day to boost the signal and what happened was that I lost All the Channels except for channel 5 and it was coming and going. This Amp. was am ANT-1005 when I took it off I got my channels back again. I don't really wanna try any other ones as I might have the same problem. As I did say before from the Antenna ( Tower ) to the T.V.it's approx. 100' I have HDTV DTV. It's a L.G. T.V. I bought several years ago. Please help and advise. Thank you in advance.
Ted+:confused:

Marbles_00
2010-01-27, 08:12 AM
Sounds like your overloading your tuner. The ANT-1005 is a 29dB amplifier. If you don't want to replace it with another, then add a simple splitter (cap the non-used output with a load) between the amps power inserter and the TV input. This should knock down between 3.5 to 4dB (tuner will be hit with 25dB).

You may have to add more splitters or attenuators to knock the signal down more until the tuner is no longer overloaded.

ProjectSHO89
2010-01-27, 08:37 AM
Hi,
I put on an Amp. the other day to boost the signal and what happened was that I lost All the Channels except for channel 5 and it was coming and going. This Amp. was am ANT-1005 when I took it off I got my channels back again. I don't really wanna try any other ones as I might have the same problem. As I did say before from the Antenna ( Tower ) to the T.V.it's approx. 100' I have HDTV DTV. It's a L.G. T.V. I bought several years ago. Please help and advise. Thank you in advance.
Ted+

Remove the amp. Installing it was the wrong thing to do since, as noted, it is overloading.

Indiscriminately "boosting" signals usually results in worse problems than the issues you were trying to solve (if there were any in the first place).

Using a "junk" amplifier usually makes it even worse.

mlord
2010-01-27, 10:41 AM
Yes, it's junk. The maker quotes a 5db NF for that pre-amp, which is just at the threshold which makes them generally useless.

Below 5dB NF might actually help, if the gain isn't cranked up to ghetto blaster volumes like that one was.

Your LG TV has a very good (XC5000) tuner chip inside, and the only way you'll help that, is if the pre-amp has a *very* low NF, like 1dB or less.

Cheers

mlord
2010-01-27, 10:47 AM
So their profit margin is pretty high then, based on just the hardware. :) I don't know what their sales volume is like though.;)
I know that you are kidding there, but for the benefit of non-techies in the crowd..

I'm amazed that Kitztech is making any kind of a living off of their pre-amps. Figure they cost about $15 in parts (wholesale), then another $10/minimum wage to assemble+test each one, and there's barely a 100% markup over cost there.

Minus all of the expenses of running a business, web site, etc..

Just enough, I suppose.

Cheers

Jase88
2010-01-28, 07:33 PM
Both amps generate about 5dB of noise. That's simply too high. Definitely not recommended.

GeoStar
2010-01-29, 01:31 PM
new kitz
The noise figure should be about .4 db with again of 26 db to 22 db.

mmm and since my kitz pre amp is in the basement ( = easy swapout) when this new lil baby comes out I may buy it and swap it for the one that is there now. The orginal would become my backup just in case.( or I'll upgrade my dad's system , he would like the better signal and OTA would grow ) -:D

Yes and with a roof top tenna maybe I could start to see the light of pbs 23 :cool:

can't be more than say $125.00 could it ?
what is the optimum price based on elasticity to sales figure for a product in this catagory , any economists out there ?

meanwhile the home automation with misterhouse slowly grows in the dark.......anyone know were to buy a good touchscreen panel pc with xp embedded 1 gig ram 10 inch screen ?

balm
2010-01-29, 01:50 PM
dont be surprised for HUGE price jump, given RCs amps are over $200, with similar specs, and more demand now

also, im sure, at $40-$60 with their previous amps, and probably very low volume, they werent making HUGE profits..

so this means catch-up time! just my opinion ;)

GeoStar
2010-01-29, 03:05 PM
Huge price jump mmmmm maybe , for short run sucess

but a product like that sure makes for a nice target for some off shore manufacturer to take advantage of the price differential, once the market is there ie all the dirty work is done.. and --- I'd really rather buy local ..

when the honda civic was a hit, they introduced the accord-- grow with us they said , what was the adjusted price variance on that product ?

mlord
2010-01-29, 05:54 PM
dont be surprised for HUGE price jump, given RCs amps are over $200, with similar specs
RC pre-amps are priced at exactly UK45/each, which is less than CDN$100.

Of course, one can spend (a lot) more on that with pricey accessories, like their tank-like PSU and similarly overengineered enclosure. But much cheaper solutions exist too.

Cheers

Muus
2010-01-30, 05:26 PM
I have a Winegard MS-1000 (un-amplified omnidirectional) antenna above the peak of my house (about 30' above ground). I'm considering installing an HDP-269 but I want to be sure I don't overload the amp or my TV tuner (Sharp Aquos).

You may be thinking I have nothing to worry about since the MS-1000 has very little gain but the problem is, I'm 5 miles from a tower with strong VHF and FM transmitters. The HDP-269 does have an FM trap but hopitup2000 has indicated that it isn't very effective between 88-100 Mhz. Unfortunately, there are many strong stations that fall in this range. (Why does the Preamplifier Comparison Chart found on the first page indicate that the HDP-269 does NOT have an FM trap???)

Fortunately, I have an old Jerrold signal meter that I used to get the strength of the strongest stations (only channels over 1 mV);

CH 4 - 14 mV
CH 6 - 3 mV
FM 88.5 - 3 mV
FM 89.9 - 10 mV
FM 90.7 - 16 mV
FM 91.5 - 18 mV
FM 93.9 - 14 mV
FM 94.9 - 10 mV
FM 97.1 - 10 mV
CH 9 - 6 mV
CH 13 - 4 mV
CH 24 - 1 mV
CH 30 - 2 mV
CH 34 - 1 mV

If I only count the ones over 5 mV that's 8 channels which means the HDP-269 has a maximum input of -22.6 dBm (-14.6-8) or 20.3 mV. Seeing as the strongest station is 18 mV I should be OK right?

Now what about the tuner in the TV? I have an CA-8800 FM Band Separator so that should reduce some of the FM signals from getting to the TV. The strongest VHF station is CH 4 @ 14 mV or 23 dBmV. Do I simply add the amplifier gain (12 dB) to get 35 dBmV or 56 mV? Will that overload the TV tuner?

In case you were wondering, the reason I need the amplifier is that there's a digital channel on 66 which I am unable to receive. I'm hopping that the pre-amplifier will be able to help pull it in. The channel is broadcast from a tower 20 miles LOS from which I can receive all other analogue and digital channels.

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2010-01-30, 09:20 PM
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roger1818
2010-02-01, 12:20 PM
Muus, since most (and the strongest) of your strong stations are on VHF/FM, my suggestion would be to only amplify UHF. You can do this either with an amplifier that passes VHF unamplified (such as the Winegard AP 4700) or by using two UVSJs (one before the pre-amp to split VHF and UHF and one to combine them together again after the pre-amp). The biggest problem with the second solution is the UVSJ won't pass power on UHF, so you will need to put the second one after the power injector. Also, the UVSJ will give you a small amount of insertion loss on UHF before the pre-amp, which could be a problem.

holl_ands
2010-02-01, 02:32 PM
I have a Winegard MS-1000 (un-amplified omnidirectional) antenna above the peak of my house (about 30' above ground). I'm considering installing an HDP-269 but I want to be sure I don't overload the amp or my TV tuner (Sharp Aquos).

You may be thinking I have nothing to worry about since the MS-1000 has very little gain but the problem is, I'm 5 miles from a tower with strong VHF and FM transmitters. The HDP-269 does have an FM trap but hopitup2000 has indicated that it isn't very effective between 88-100 Mhz. Unfortunately, there are many strong stations that fall in this range. (Why does the Preamplifier Comparison Chart found on the first page indicate that the HDP-269 does NOT have an FM trap???)

Fortunately, I have an old Jerrold signal meter that I used to get the strength of the strongest stations (only channels over 1 mV);

CH 4 - 14 mV
CH 6 - 3 mV
FM 88.5 - 3 mV
FM 89.9 - 10 mV
FM 90.7 - 16 mV
FM 91.5 - 18 mV
FM 93.9 - 14 mV
FM 94.9 - 10 mV
FM 97.1 - 10 mV
CH 9 - 6 mV
CH 13 - 4 mV
CH 24 - 1 mV
CH 30 - 2 mV
CH 34 - 1 mV

If I only count the ones over 5 mV that's 8 channels which means the HDP-269 has a maximum input of -22.6 dBm (-14.6-8) or 20.3 mV. Seeing as the strongest station is 18 mV I should be OK right?

Now what about the tuner in the TV? I have an CA-8800 FM Band Separator so that should reduce some of the FM signals from getting to the TV. The strongest VHF station is CH 4 @ 14 mV or 23 dBmV. Do I simply add the amplifier gain (12 dB) to get 35 dBmV or 56 mV? Will that overload the TV tuner?

In case you were wondering, the reason I need the amplifier is that there's a digital channel on 66 which I am unable to receive. I'm hopping that the pre-amplifier will be able to help pull it in. The channel is broadcast from a tower 20 miles LOS from which I can receive all other analogue and digital channels.
I happen to be looking at the HDP-269 right now...it has a couple of inductors on the input, but certainly
won't be attenuating the FM band all that much. And even a purpose-built FM Trap has limited effectiveness,
since most of the inexpensive ones are simple notch filters that only take out a small portion of the FM Band.
If the FM stations are truly keeping you from receiving some weak stations, you should be looking at the more
expensive FULL-BANDSTOP filters....which will also attenuate your Ch6....fortunately, it's strong to begin with....

Your old (NTSC only) Jerrold Signal Level Meter probably only measures a limited bandwidth,
and then there is the NTSC Peak to ATSC Average power conversion.
For the Potomac FIM-71/72, readings are reduced by 12 dB:
http://www.pi-usa.com/pdf/dtva.pdf

So why do you think you NEED a Preamp, esp for VHF??? At 20-mi LOS, Ch66 isn't going to be helped.
What will help is a more directional antenna to suppress MULTIPATH....
Those high signals are also going to clobber adjacent, next-adjacent and perhaps even further away.....

Charles Rhodes has a new article re FM Interference (FMI) to DTV in TV Technology Magazine.
http://www.tvtechnology.com/article/93086
Here are some earlier articles:
http://www.tvfmtranslators.com/PastPapers/2009/CharlesRhodesNTA2009FMixtoTV.pdf
http://www.tvtechnology.com/article/82716
http://www.tvtechnology.com/article/88282

roger1818
2010-02-01, 03:11 PM
So why do you think you NEED a Preamp, esp for VHF???

In Muus's original post he said:

In case you were wondering, the reason I need the amplifier is that there's a digital channel on 66 which I am unable to receive. I'm hopping that the pre-amplifier will be able to help pull it in. The channel is broadcast from a tower 20 miles LOS from which I can receive all other analogue and digital channels.

So he doesn't need a pre-amp for VHF. He does want one for UHF however, which is why I recommended the AP 4700 instead.

This is, of course, assuming that his setup justifies the use of a pre-amp (more than about 50 feet of coax or at least one splitter).

roger1818
2010-02-01, 03:22 PM
The HDP-269 does have an FM trap but hopitup2000 has indicated that it isn't very effective between 88-100 Mhz.

What makes you think the HDP-269 has an FM trap? The Spec Sheet (http://www.winegard.com/kbase/upload/WC-809%20_HDP-269.pdf) doesn't say anything about one and the HDP/AP Series Manual (http://www.winegard.com/kbase/upload/2451964.pdf) says "FM TRAP OPERATION (Not applicable to Models AP-4700, AP-4800, or HDP-269)."

holl_ands
2010-02-01, 03:24 PM
In Muus's original post he said:



So he doesn't need a pre-amp for VHF. He does want one for UHF however, which is why I recommended the AP 4700 instead.

This is, of course, assuming that his setup justifies the use of a pre-amp (more than about 50 feet of coax or at least one splitter).
It is also likely that the MS-1000 antenna just isn't providing much gain on Ch66 due to it no longer being an "OMNI"
at that extremely high freq....plus whatever LOSS is inherent in that antenna. Rotating to find the "peak" may help some....

What were the signal strength reading for Analog Ch60 & 65??? Were they significantly lower than Analog Ch40 & 43???
I ran the Lat/Long for Hull, QC through www.tvfool.com, which found them be about the same signal strength.
There is also the possibility that Ch66 isn't running with the power levels assumed by tvfool, making it susceptible to
adjacent channel interference from Ch65.

Bottom Line: Try a better antenna. Multipath may be the culprit....

hoopitup2000
2010-02-01, 03:49 PM
What makes you think the HDP-269 has an FM trap? The Spec Sheet (http://www.winegard.com/kbase/upload/WC-809%20_HDP-269.pdf) doesn't say anything about one and the HDP/AP Series Manual (http://www.winegard.com/kbase/upload/2451964.pdf) says "FM TRAP OPERATION (Not applicable to Models AP-4700, AP-4800, or HDP-269)."
If you contact Winegard directly, they will verify that there is indeed an FM trap in the HDP-269. I spoke with Hans who is one of their engineers who confirmed this. I am hoping the error will be corrected in the literature at some point.

roger1818
2010-02-01, 04:40 PM
It is also likely that the MS-1000 antenna just isn't providing much gain on Ch66 due to it no longer being an "OMNI"
at that extremely high freq....plus whatever LOSS is inherent in that antenna. Rotating to find the "peak" may help some....

All very true. Omnidirectional antennas do not provide equal gain in all directions and need to be tweaked for maximum gain.

What were the signal strength reading for Analog Ch60 & 65??? Were they significantly lower than Analog Ch40 & 43???
I ran the Lat/Long for Hull, QC through www.tvfool.com, which found them be about the same signal strength.

I would ignore Ch40 as it is coming from a different tower, but Ch43, Ch60, Ch65 and Ch66 all come from the same tower. For his location (found in an old post of his) Ch43 should be about 4dB lower than Ch65.

There is also the possibility that Ch66 isn't running with the power levels assumed by tvfool, making it susceptible to adjacent channel interference from Ch65.

There is something funny about Ch66 as many people have troubles with it. I wonder if it could be adjacent channel interference with Ch65. They are broadcast from the same tower, but not the same antenna (Ch65 is higher) despite the fact that Rogers now owns both stations (and the tower). My hope is the problem will go away after the analog shutdown and it moves to its final allotment.

Bottom Line: Try a better antenna.

I am starting to think the same thing. Normally a fixed, directional antenna wouldn't work well when the broadcast towers are about 135 degrees apart, but he is so close to Camp Fortune that pretty much any antenna pointed in any direction should pick up all those channels, and the increased gain would help pick up the channels from Hebert's Corners (namely Ch66).

ProjectSHO89
2010-02-01, 06:46 PM
Muus, since most (and the strongest) of your strong stations are on VHF/FM, my suggestion would be to only amplify UHF. You can do this either with an amplifier that passes VHF unamplified (such as the Winegard AP 4700) or by using two UVSJs (one before the pre-amp to split VHF and UHF and one to combine them together again after the pre-amp). The biggest problem with the second solution is the UVSJ won't pass power on UHF, so you will need to put the second one after the power injector. Also, the UVSJ will give you a small amount of insertion loss on UHF before the pre-amp, which could be a problem.

Roger,

It's a lot simpler is you simply select a U/V diplexer with power pass-through on the UHF port if you wish to amplify UHF only.

Radio Shack and Antennas Direct have units that do so. The common Holland and Pico Macom UVSJ units are DC-Pass on the VHF port.