Band Pass filter review by WL7CLA
Eham review by WL7CLA
Where I live I get blasted by broadcast stations and I have very limited antenna room, so isolation between 6M, 2M and 70cm antennas is an issue as well. I have 6M and 2M high power TX bandpass filters, as well as RX only 2M and 70cm filters installed in front of my LNAs. (I have 6 or 7 filters total make by YU1CF)
All are very nice build quality and measure out exactly to published specs.
You can read full review here.
Testing band pass filters
Received the filter weeks back.
Overall sweeps look just like yours. 50-54 sweep matches yours as well.
Compared to a silver plated amphenol barrel with multiple measurements across multiple days I get .09 to .1 db loss (50 solidly at .09, 53-54 flipping back/forth .09/.1 reading to reading (2 digit after decimal display limit, so around .093 to .097.
Was not surprised it was a good quality filter, but was very surprised to get readings that close.
The 6M and 2M TX bandpass filters are installed inline after amps and doing well.
The 2M and 70cm receive only bandpass filters are installed in my terrestrial LNA assemblies protecting the LNAs from broadcast/business band overload and from my antennas being too close. I keep one 2M and 70cm filter in the shack on the test bench.
Very, very happy with all of them.
Picture of some band-pass filters WL7CLA purchased:
Link of all band pass filters is here.
List of all band pass filters purchased by WL7CLA:
- 2 meter Receiving band pass filter
- 70 cm Receiving band pass filter
- 50 – 54 MHz 4 kW band pass filter
- 144 – 148 MHz 4 kW band pass filter
- 430 – 440 MHz 4 kW Band pass filter
What are band pass filters used for:
If you are new at Ham Radio you might want to read bit more about what band pass filers are used for:
Band pass filters are widely used in transmitters and receivers. The main function of such a filter in a transmitter is to limit the bandwidth of the output signal to the band allocated for the transmission. This prevents the transmitter from interfering with other stations. In a receiver, a band pass filter allows signals within a selected range of frequencies to be heard or decoded, while preventing signals at unwanted frequencies from getting through.
Signals at frequencies outside the band which the receiver is tuned at, can either saturate or damage the receiver. Additionally they can create unwanted mixing products that fall in band and interfere with the signal of interest. Wide-band receivers are particularly susceptible to such interference. A band pass filter also optimizes the signal-to-noise ratio and sensitivity of a receiver.
In both transmitting and receiving applications, well-designed band pass filters, having the optimum bandwidth for the mode and speed of communication being used, maximize the number of signal transmitters that can exist in a system, while minimizing the interference or competition among signals.
We have wide range of band pass filters. You can find them here.