LTE Filter for TV Antennas, 4G 5G LTE Signals to Reduce Interference and Pixelation, for Clear Digital HD TV Reception, 5-608MHz Frequency Range, Indoor Outdoor Installation, SDW1520/27

他社製品で2個$14.99と、もっとお安くて170〜695MHz対応のものがあったのだが、米アマのレビューコメントでオシロの計測画面とともに丁寧に競合比較をしている人がおり、本品がベストとしていたので選択。 米アマの単価$9.40x2個の$18.80に、送料手数料$10.97の合計$29.77(2023年7月28日現在で約¥4150)で購入した。 輸入(米アマからみて輸出)だと米国消費税相当の小売売上税はかからない。総額で安いと日本の輸入消費税もかからないから、まずまず良いディール。 日アマでの販売価格は¥3265と、1個買うだけだと輸入するメリットはないが、2個以上または他にも一緒に買うものがあれば、到着まで約1週間かかるものの、悪くないと思う。 アメリカでの600MHz帯5Gの放送波への干渉を抑止するフィルタであるため、通過上限周波数の公称値が608MHz(日本の物理チャンネル35あたり)になっているのがキモ。 例えば、スカイツリーからの関東広域なら、最もハイバンドなNHK総合でさえ物理チャンネル27だから、余裕でカバーできる。 地域によって地デジ視聴に必要な物理チャンネル(周波数帯)は異なるから、フィルタ上限が710MHz以下の海外製品を購入する際は、自分の環境に注意する必要がある。

電波が良くなった(^^♪60～75までしか無かった電波が90まで出るようになった('艸｀*)

急にブロックノイズが出始めたので、LTEが、原因と思い、取り付けたが改善せず、後日別の原因とわかり、現在は改善 しました。とりあえずそのまま取り付けています。

NHKとNHK Eテレと関西テレビが映らなくなりました。

جيد

Works great, it definitely amplified my television antenna’s reception. I am now able to pick up additional television channels that I once wasn’t able to pick up. I would highly recommend this television antenna amplifier which works with other television antenna brands.

Installed on my setup and hope it work as expected

For those who don't know what this product is about, a quick (simplified) summary of major changes to Over-the-Air Television in the United States. UHF TV reception in the US originally consisted of channels 14 to 83 (460 to 890 MHz) introduced through FCC regulation in 4/11/1952. The 800 MHz portion (channels 70 to 83) of the UHF TV band were reallocated already back in 1983 for other services (including but not exclusively to mobile telephone service). Effective 6/12/2010 (immediately following the Analog to Digital TV conversion) the 700 MHz portion of the UHF TV band (channels 52 to 69) were auctioned off by the FCC of which AT&T (band 12, 699 to 746 MHz) and Verizon (band 13, 746 to 787 MHz) were the major winners. Since then the FCC conducted a "repack" requiring TV broadcasters to move from upper UHF channels to lower UHF channels or back to VHF (were many stations were broadcasting prior to the Analog to Digital TV conversion), including to the low-VHF band that was originally deemed unsuitable for digital television. In 2017 the FCC then auctioned off the 600 MHz portion of the UHF TV band (channels 38 to 51) of which T-Mobile was a significant winner (band n71, 617 to 698 MHz). TV broadcasters had until June 2020 to complete their relocation and to free up the 600 MHz spectrum. TV channel 37 has been and continues to be a reserved channel for radio astronomy which means that the usable UHF TV band has shrunk to channels 14 to 36 (460 to 608 MHz). All of the above refers to the actual RF channels on which your local stations really transmit (which has absolutely nothing to do with the channel numbers your TV will display). Depending on how old your TV tuner is, it will be designed to receive signals from the 600, 700 and possibly (so less likely) 800 MHz ranges which no longer contain any TV programming. The mostly mobile phone transmissions on those bands can interfere with the TV programming you are actually interested in. To prevent nearby cell towers and even your own cellphones from interfering with your TV reception, a number of companies make filters to block the unwanted signals from getting into your TV. This product (Philips SDM1520/27) is one of those products. It was half as expensive as a similar product (ChannelMaster CM-3201 also here at Amazon) which I also purchased. Needless to say, I was curious whether or not the higher price of the CM-3201 was worth it and I wanted to rely on science instead of subjective testing (e.g. how many times a particular channel pixelates within an hour). I therefore used a NanoVNA-H4 to measure the filter characteristics. I'll state upfront that using test equipment for 50 Ohm impedance with 75 Ohm impedance filters does introduce some errors into the measurements, however since this is the same impedance mismatch in both cases it still results in a valid comparison. An ideal (impossible) filter would have no attenuation below the cut-off frequency and infinity attenuation for any frequency above it (meaning that there would be no transition band at all). Real filters reveal their quality by how much they attenuate unwanted signals and how wide the transition range is (the frequencies between start of attenuation and full attenuation). Both filters showed a start of attenuation at 606 MHz (first visible sign of attenuation in the LogMag trace, not the 3dB attenuation commonly used to characterize filters) which is still within the frequency range for TV channel 36 (I subsequently tested the filters on a local station that uses RF channel 36 and the reception was fine). Also both filters showed reasonably low figures for insertion loss (the attenuation of a good signal just because the filter is being added). The ChannelMaster CM-3201 showed a transition band of 36 MHz (less is better) and attenuation of nearly 60dB (more is better, but 60dB is already excellent). The Philips SDM1520/27 (this product) showed a transition band of 72 MHz (a bit disappointing that it is so wide) and attenuation of about 30dB (which is good, but higher would be better). In-line filters are often symmetrical and can be used in either direction. Both the CM-3201 and the SDM1520/27 have explicit input and output markings but I did not test whether the filters behave any different when used backwards. The Philips SDM1520/27 is significantly smaller in diameter which may be an advantage on some TVs with recessed antenna connectors. Bottom line, this filter does work and while it is not as impressive as the more expensive one I compared it with, keep in mind that it only costs half as much. I don't see any reason to deduct a star in rating just because a more expensive product has better test results. Not everybody may need these filters (locations of TV and cell transmitters play a big role) and if you do, you may get satisfactory results from this cheaper filter. If you are concerned about getting the best results spend the extra money on the ChannelMaster CM-3201. However beware of any filters that are still sold which are based on the 2010 elimination of the 700 MHz band since those are not blocking cell transmissions in the 600 MHz range.

We have moved into a rental property while waiting for our new home to be completed; the property only has an older style analogue antenna and we were constantly getting 4g and 5g signal interference making free to air TV stations unwatchable. We purchased the filter, Amazon delivered it less than a week, it took 2 minutes to install and our reception is interference free. We are very happy.