Question: Radioshack inline amplifier

#1
Anyone know anything about the RadioShack inline amplifiers? #15000528 It is two pieces with the "amplifier" piece going close to the antenna and the "power injector" close to the TV. The instructions state a couple times to not mount the amplifier piece outside but you want it close to the antenna and not far down the line. My problem is I have to run about 40 feet of coaxial before I can get inside and am afraid that might be too far from the antenna. What is the threat of mounting the amplifier piece outside? It is sealed up pretty good and I could just wrap it in rubber or something to water proof all the way.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#2
Do you mean this one? RadioShack Inline Antenna Signal Amplifier - RadioShack.com ?

It is common practice to place the amplifier as close as possible to the antenna. In most cases, this means OUTDOORS. I was taken aback reading the manual where it says "Do not install outdoors"! Also, the noise figure is awfully high (4 dB!)

You would be better to get this: RCA TVPRAMP1R Outdoor Antenna Preamplifier : Antenna accessories | RadioShack.com - but they don't stock them in-store. Also available online at Amazon and Walmart for cheaper than Radio Shack.
 
#3
Thanks! That is the one. I already bought it so going to try and make it work. Sucks about the extra noise but I got it cheap on eBay and it picks up the channels I was trying to get. I just can't figure out what the big deal is with mounting this outside when it needs to be close to the antenna anyways. I am going to wrap it to keep rain and snow off and give it a try. Just hope a potential short at the amplifier does not send some kind of surge down the line or something and ruin my tv.
 
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MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#4
Seal it with silicone seal and hope for the best. It should last for a while - long enough to purchase a good one as a backup for when that one fails. I doubt there is any real danger, it's a low voltage DC device.
 
#6
Very little information is available on that little amplifier. I did read the instructions, and the 3 product reviews. I would guess there is a reason they say not to put it outside. The instructions would indicate that it has no FM or out of band filtering, and is simply a single broadband amplifier. That could cause problems in some areas. There are better pre-amp choices available for the money like the RCATVPRAMP1R. I would probably try to weather proof it, and use it, but keep in mind I am a person that does everything wrong at least three times before I get it right. I learn a lot that way, but waste a lot of time, and money in the process. Reading the reviews I would guess that the one negative reviewer wasn't getting power to the amp because of bad coax connectors. A very common problem I've experienced. An amplifier should never be looked at as a magic solution to signal problems as they can often times create more problems. When properly selected and installed an amplifier can be useful, and sometimes necessary part of an antenna system.
Steve
 

Antennafreak

DTVUSA Jr. Member
#7
I've got the rca tvprampr1 and it works so good that without it I get one channel and with it I get 32. I've also had a channel master cm-7777 and even with the higher gain on the cm-7777 the rca kicks its butt. Rca's little pre amp has the best noise margin I've see.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#8
I've got the rca tvprampr1 and it works so good that without it I get one channel and with it I get 32.
Antennafreak,

In my 40+ year experience with OTA reception, I've never seen anything like your report (above).

I suspect you are using waterlogged or otherwise damaged coaxial cable and your amplifier is 'compensating'.

Jim
 

Jim5506

DTVUSA Member
#9
That little RS pre-amp has its F connectors exposed to the weather, you'll notice all the weather proof ones have the f connectors nestled up under a cap that sheds water away from them.

Unless you seal the F connectors with silicone or similar, moisture will work its way into the amplifier and corrode the connections, you may have to replace the pre-amp and your coax.
 
#10
I have to agree with Jim. I know from experience that high SWR from a damaged balun, feed line, or antenna can selectively filter out some frequencies causing missing channels even when signal levels are high. This is a phenomenon that caught me by surprise the first time I suddenly had one missing channel. An ohm meter and a continuity check of the coax solved the mystery. ATSC signals do some strange things when SWR on a feed line goes through the ceiling. Having the preamp close to the antenna provides a good impedance match between the amplifier and the receiver which can help make up for the mismatches on the antenna side of the amplifier. I personally have no experience with the RCA preamp, but in my reading have read many good reports including independent test done by a competitor, a few product failures, and a lot of user error. I am also one who has over 40 years experience working with radio and television antennas, and I'm not done yet I'm still just a beginner with a lot to learn.
Steve
That should be both Jims I'm slow to post.
 
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Antennafreak

DTVUSA Jr. Member
#11
Yeah I thought it was weird too. I do have one older coax cable still, otherwise the rest are all brand new quad shield. I will have to replace the remaining coax when I get some time.
 
#12
Antennafreak what you reported is highly unlikely, and could only happen if something else is damaged on the antenna side of the amplifier. Amplifiers do not magically pull signals out of the air when no signal is present. Amplifiers always decrease the reliability, and increase the complexity of an antenna system. More parts to fail. More parts to be installed incorrectly, or if there are switches involved incorrectly set. More connectors, and components to trouble shoot when something does go wrong. Amplifiers are known to over load from near by broadcast, or other radio service signals. Channel Master has warnings on there web site about over amplification when using the CM7777. I have successfully used both pre-amplifiers, and distribution amplifiers to solve reception problems. I've also experienced most of the problems that an incorrectly selected, and installed amplifier can cause.
Steve
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#13
Steve is SO right about his preferrence to not use any amplifiers whenever possible and that is my position. If an additional 3db of signal is all it takes to stabilize a signal, I would install an antenna that has 3db or more gain beyond the existing antenna and never have to worry about added 'noise' to the received signals or amplifier failures.

In another scenerio, point-to-point OTA TV reception is like a bicycle riden from A to B. My one-speed bicycle gets me there and rarely breaks down, but you can be "cool" if you have a special 18-speed Italian racing bike that accomplishes the exact same thing as the one-speed ... but "your bike" will need continual tuning and work to keep it going and "my bike" hasn't needed any work in 6 years.

Jim
 

Antennafreak

DTVUSA Jr. Member
#14
Well in all the years I've used amps I've rarly rarly had to replace them. And even thou it seems unlikely that the amp helps so much, believe it or not I am not a magical story teller. I don't pull lies out of my butt. Come over sometime so I can show you. I love company. I'll feed you even. If you remember my tv fool report you will see that all but channel rf 12 are low db and unlikely to be picked up in my area. But I have a large number of signals coming from the same tower that are all low power that I am well outside of the service contour map. Past the point they are supposed to cover. To me that makes sense that adding and amp would pull them all in. Lik it or not, amps help. Sure it's something else to go bad, but in many cases, you just need one.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#15
Yes, amps can help. But I use them only as a last resort, or to overcome long cable runs or multiple splits of coax. NEVER start with one. See how the system functions first, and look for all other things that may be interfering with reception. I've had to remove amps several times to make a system work, either because it wasn't needed or it was a bad amp.

If an amp gets you the channels you want, it's probably because you should have installed a higher gain antenna to begin with.
 
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#16
I've no problem receiving low power UHF translators from 30 miles away with a home built single bow tie antenna 50 feet of RG6, and no amplifier.
TV Fool
UHF Bowties - NO Reflector
You seem to have totally missed the statements I made about the usefulness of both preamplifiers, and distribution amplifiers.

When properly selected and installed an amplifier can be useful, and sometimes necessary part of an antenna system. - See more at: http://www.dtvusaforum.com/dtv-hdtv...0-radioshack-inline-amplifier.html#post135698
I have successfully used both pre-amplifiers, and distribution amplifiers to solve reception problems - See more at: http://www.dtvusaforum.com/dtv-hdtv...0-radioshack-inline-amplifier.html#post135698
At my previous location.TV Fool I had used a Radio Shack VU90-XR, 75 feet of RG6, and a Radio Shack 15-321 amplifier. On that installation at that location combined with my lack of knowledge at the time the amplifier was needed to make things work. Yes in the right situation an amplifier can solve reception problems. In the past I had tried different amplifiers with different antenna combinations I've had over the years, and most of the time had found them to be a total waste of money. Most of the television antenna work I've done over the years has been with low, and high band VHF NTSC signals with less then 50 feet of coax. Both UHF and ATSC signals are pretty new to this part of the world. I'm not against the use of signal amplifiers, but I do want to make people aware that they are not a cure all for reception problems. I make mention of all the problems one can run into when using an amplifier because I have personally experienced them, and spent the time trouble shooting the antenna system, making repairs, and waiting for parts.
 
#17
We have answered the OP's original question. Now let's move on while I dream up my latest amplified, multi-directional, compact home brew super antenna, that uses NASA and military technology and can be built for less than $40 using junk box, Walmart, and Dollar store parts.
Steve
 

Antennafreak

DTVUSA Jr. Member
#18
I agree. In my system I did only use it as a last resort. Trust me, I don't like that I need an amp. If I had the money and a less slanted better access roof, I could get a bigger antenna higher up, over the neighbors tree,and it would function without an amp. And I'll take one of your nasa antennas when done.
 

Tim58hsv

DTVUSA Member
#19
I agree. In my system I did only use it as a last resort. Trust me, I don't like that I need an amp. If I had the money and a less slanted better access roof, I could get a bigger antenna higher up, over the neighbors tree,and it would function without an amp. And I'll take one of your nasa antennas when done.
I couldn't agree more. I don't know why people love to demonize preamps so much but they do. I've said before on here that I live 3.5 mile from the Dayton, Ohio TV towers (you can see them out the back door) and use a preamp on my outdoor Antennacraft U4000 antenna to pick up channels from the Cincinnati TV market 45 miles away.

AND THE DAYTON CHANNELS DO NOT CAUSE MY PREAMP TO OVERLOAD!
Sorry, but I had to scream that. :)

Without the preamp I can't pick up any channels out of Cincinnati except channels 5 and 9 so a preamp is necessary unless I use a bigger and more powerful antenna and raise it maybe 50 feet or more in the air? No thanks. I'll use a preamp instead.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#20
Tim,

I liked your post (only) because you understand how your personal antenna systems works in your specific location.

I am writing this to Forum readers, not to you: however, the casual 'drop-in' Forum reader here may already think (or be encouraged to think) 'bigger is better' ... stronger signals are necessary and that is often, false.

Clean, weak TV signals always trump noisy high-level signals and all amplifiers add 'noise'. Its always best to establish reception using one antenna feeding one TV and move the antenna around to find the 'best' (most dependible) signals. Antenna height and location - up/down/right/left. Once you have determined the best location for your antenna, try splitting the received signals.

Depending on your results, it might be time to try an antenna pre-amplifier to see if there is a difference.

The next step might be a distribution amplifier.

Jim

PS Of course, I'm talking about a home and not an apartment building or a condo ...
 
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