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Reviews For: Radio Shack In-Line Signal Amplifier

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Review Summary For : Radio Shack In-Line Signal Amplifier
Reviews: 3MSRP: 29.99
50 MHz - 2.2 GHz In-line signal amplifier (10 dB gain) utilizing F-type connectors for 75-ohm cable. Amplifier mounts at the antenna and a power injector supplies the power at the "receiver end" of the cable.
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
N4WCQ Rating: 2010-01-31
Good preamp for scanners Time Owned: 0 to 3 months.
This is a nice inexpensive preamp for scanners. I use one to boost the signal before I split it to feed multiple scanners. The first time I put the preamp at the antennae (disconne) it lasted less than 24hrs and a small storm took it out. I replaced the rf amp ISL55007 and put it inside at the splitter.
KB1MVZ Rating: 2005-12-15
OK... below 800MHZ Time Owned: more than 12 months.
For the money, this is a pretty decent pre-amp, which is surprising considering where you buy it. I've owned several over the past (maybe five?) years, and typically used them to overcome coax signal loss, particularly in the VHF bands.

Though this pre-amp is supposedly rated through the gigahertz range, I find mine to actually insert significant signal LOSS at 800MHZ.

One final note: Though they look identical externally, the parts (and voltages) used in this product have changed over time... so, it's hard to know the exact performance of the device you're buying at any given time... so your mileage with this part may vary.
N4UE Rating: 2005-12-05
great! Time Owned: 0 to 3 months.
I was in the local RS the other day poking around for accessories to use with my latest "toy", a Icom R7000. They have a neat little in-line preamp for around $13, but they do NOT have a power injector which would allow this to work.

BTW, even Lowes sells the in-line preamps but NO DC injector.

Looking further, I noticed this preamp which has the DC injector, and a DC block.
I already have an older Channel Master in-line preamp which covers 50-900 Mhz. Since the R7000 goes to 2 Ghz, I thought this preamp would be a good match.


This amp has a very small advantage over the CM, but the coverage is much more broad.
Using a RS Discone and either amp, I can hear AM Aircraft signals very clearly that are 'in the noise' without the amps.
Using the RS and CM amps to listen in on an Es opening on 6 Meters yesterday, revealed a dramatic increase in the reability of the signals. Although the Discone antenna is great for what it is, it IS a ZERO gain antenna, so some help is necessary. I would liked to put the preamp AT the antenna where it would do the most good, but since I use the antenna to transmit on (for now), it's a big NO.

It took me a while to figger out the 'manual'. Never having had a scanner before (or a preamp such as this), it was a little confusing.

I couldn't figure out why they put a DC block on the antenna side of the amp. I later realized it was there in case you use a 75 ohm to 300 ohm transformer at the antenna. In this case, it would present a short.
I ended up leaving that DC block there and putting another on the input side. That way, there is NO possibility that a reverse connection will produce a DC voltage into the radio. With my luck, this would be likely!!! Checking several different very weak signal UHF stations, the DC block had NO effect on the signal. Cheap insurance!

BTW, the DC block is a 1000 pf cap in series with the center conductor.

I asked if I could return the unit if I was unhappy with it. I was told "certainly" which made me feel good. The unit works so well, I'm keeping it.

When I get my 'real antennas' up, the preamp will go UP at the antenna. That way, the feedline loss will not add to the system noise figure....

I like it!