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Reviews For: Radio Shack 2 Line Telephone RFI Line Filter

Category: Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI

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Review Summary For : Radio Shack 2 Line Telephone RFI Line Filter
Reviews: 7MSRP: 14.49
Description:
Reduce radio interference on both lines. Radio Shack's 2-Line Telephone Line Filter eliminates most broadcast, CB and amateur radio interference by reducing RF current on telephone wiring before it reaches your equipment. Convenient modular (RJ-11 type) connections allow use at your phone or wall jack. Can also be used for single line telephone. 25dB Rejection from 3-30MHz range. Insertion Loss from 300Hz to 3KHz: <1dB. Open Circuit DC Impedance: >5M Ohms.
Catalog #: 279-151
Product is in production
More Info: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F008%5F008%5F001%5F007&product%5Fid=279%2D151&hp=search
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0074.3
K8SDK Rating: 2006-12-27
Works Great Time Owned: 3 to 6 months.
I bought 2 of these for my neighbor's phones, which had VERY long cords (antennae), and which were picking up my transmissions on 15M SSB. Cleaned it right up.
WB1AEX Rating: 2006-12-26
Open it up and look inside... Time Owned: 0 to 3 months.
Well, I hate to throw cold water on this filter, but it did not make the slightest difference at my location, where 75 meter and 160 meter operation caused one of my phones to ring when I keyed the amplifier. Opening the filter up revealed what appeared to be a resistive decoupling network and two unmarked capacitors. There are no RF chokes in this filter. I cured my problem with 2 inline 200 microhenry chokes (one in series with red and one in series with green) and a .01 across red and green at the terminal behind the phone. Consider doing it yourself before dropping money onto one of these.
N4OGW Rating: 2006-11-20
works with DSL Time Owned: 0 to 3 months.
I had a problem with rf taking out the DSL connection on our phone line, although there was no audible interference when using the telephone. The problem was especially bad when transmitting on the low bands, 80m/160m. Installing the filter completely eliminated the problem. So far I haven't seen any reduction in DSL speed either.
KB1IKD Rating: 2006-01-20
Performs as Advertised Time Owned: more than 12 months.
My cordless phone would ring whenever I transmitted 100 W RTTY on 40M into a coax fed dipole or vertical. No more problems after installing RS filter. Too bad they cannot be used a on touch lamp that turns on when I transmit.

de KB1IKD
K0ZL Rating: 2006-01-20
Thumbs up!!! Time Owned: more than 12 months.
Neighbor complaining of telephone RFI from my 100 watt AM station when operating on any band, particularly 75 meters. Vtech 2.4 gig cordless fones were ringing incessintly (sp?) and driving the lady nuts. Clear audio from my station on her fone line, more clear and louder than the "party to whom I am speaking"!!!

Purchased 3 each of the Rat Shack 279-151 filters, and put them on each fone one at a time, while Bonnie KB0HTC transmitted with the Heath Apache on 75 meters, 100 watts carrier and about 400 watts PEP voice modulated AM. I established that the new filter outperformed the older radio shack rectangular filter, by substituting one, then the other. The new one is more effective at removing rectified RF from the phone line.

Each time I added a filter to yet another of the neighbor's fones, the interference reduced, until it was no longer detectable. And her fones don't ring anymore! We have not tried 40 or 20 or 10 meters yet, but that will come later. I am sure that I will hear about it, if those bands are still a problem!

Well spent $48.00. I know the neighbor should pay for this stuff, but she is on a fixed imcome and likes to bake us cakes and stuff when we do work for her, so it's cool! Problem solved, anyway.

We clicked "more than 12 months" for ownership based on the older rectangular-looking filter that we have been using.

Way to go, Radio Shack!!!

K5ENA Rating: 2005-03-08
Solved our problem Time Owned: 0 to 3 months.
After reading Rob's review, I bought one hoping it would prevent my wife's computer from disconnecting on-line while I am on 75 meters. Solved the problem completely.

John, K5ENA
K6RSG Rating: 2005-03-04
Solved my Phone and Modem RFI Problems Time Owned: 0 to 3 months.
A few of these inexpensive Radio Shack 2 Line RFI filters did the job for me!

Having recently moved my HF All-mode/All-band rig into my study, with the computer's internal modem, GE 4-Line telephone, Toshiba FAX machine, and GE answering machine nearby, there were RFI problems when transmitting on 20, 40, and 80 meters. The 4-Line phone system would sound the electronic ringers, the computer's internal modem would drop the line, etc. With the problems persisting after the wiring runs were shortened and isolated as best as posible, I began to research filters.

The K-com filter units are well reputed, but much more expensive. Their single line units sell for about $17, and their two line units cost about $23. Moreover, the only place I know which sells them locally is HRO on the other side of town. The K-Y Filters reveiwed on e-ham were another alternative, but they involved an order/ship/delivery process. Plus, for my situation I'd be throwing lots of dollars at those as well.

On Radio Shack's website, I found these 2-line filters for less than the single line products offered from either of the other companies. I bought four at the Radio Shack about a mile from my QTH.

With these units inline, the phones do not false, the modem holds the line, and all the equipment happily coexists in close quarters. They work just as well on a single line wired RJ-11, and since they're cheaper than either competitor's single line filters, I simply standardized with these.

If you need RFI filters, check them out. They work for me. And, best of all on four of these 2-Line RFI filters, I saved over $30!

Very 73,

Rob
AK9G
(Previously K6RSG)