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Reviews For: PAR Electronics, Inc BCST-HPF MW Eliminate Filter

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

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Review Summary For : PAR Electronics, Inc BCST-HPF MW Eliminate Filter
Reviews: 12MSRP: 67.95
Description:
The BCST-HPF is a RX only 7 pole elliptic filter featuring very low loss from 1.8-->30 MHz (under 2dB worst case). Average MW loss 50dB. Features die cast enclosure, stainless hardware, gold/teflon SO-239 connectors and a bypass switch that effectively takes the filter out of line.
Product is in production
More Info: http://parelectronics.com/swl_filters.htm
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00125
SDP69 Rating: 2007-05-09
A Valuable Addition to the Shack Time Owned: 0 to 3 months.
When I recently moved from semi-rural Massachusetts to northern New Jersey, I figured there would be "challenges" to shortwave listening. I was too optimistic by half. Now I'm 14 miles from New York City and its numerous blowtorch BCB stations. When I set up my 97.5-foot Inverted-L antenna that worked so well in MA and turned on my Ten-Tec Rx-320, I heard WOR 710, WABC 770, and Bloomberg Radio 1130 on the 31, 25, and 19-meter bands. Utter SWL hell.

So I threw up a 60-foot Inverted-L. Some of my favorite world broadcasters were more copyable, but so was "77, WABC," Hoping to capture still less interference, I turned to a 9-foot CB whip, which was a bit better even though it lowered SW reception slightly. All antennas were grounded and impedance matched. I was stalemated.

Enter the Par Electronics's BCST-HPF. It does what Dale Parfitt says it will do. Installed before my preamp, the filter severely attenuates BCB interference, reducing it to more-than-manageable background noise. I expect that in a less congested rf environment, it would be effectively eliminated. The bypass switch is a nice touch, too.

The takeaway is this: if you're an SWL living near BCB transmitters, move. Failing that, get a Par BCST-HPF. Much cheaper. Oh, and try shortening your antenna, use your preamp with care, and follow the rest of the recommendations Dale includes on the accompanying spec sheet

This filter is a winner, definitely a 5.
K0YW Rating: 2005-04-21
thie unit is very effective on 160-80m Time Owned: 0 to 3 months.
I installed a 160m beverage receiving system here at my Southwest Colorado QTH. It consists of 3 Misek SWA two wire beverages each 660' long, giving 6 directions. The front to back ratio averages 20-25 db depending on wave angle of the signal arrival. While the receive gain was excellent at 40 and 80 meters, it was a bit low on 160M with my K2 and TS 850 receivers. I built a high dynamic range low gain(9db)pre-amp using a 2n5109 CATV amp transistor in a Broadband circuit with lots of feedback. The result was a desired improvement in the receive gain on 160. Weak DX signals that were whisper copy at full audio volume on the K2 were now comfortable Q5 copy at 1/3 to 1/2 audio gain. On 80 and 40M it was necessary to turn off the internal K2 preamp to end up with the same levels on 80 and 40 as I was seeing on 160 with the new preamp. There was a problem however.While no spurious signals were noted during daytime testing (No local strong AM broadcast signals)Some unwanted carriers were found on 160m at night. They were AM modulated and appeared to be AM Broadcast band harmonics arriving on the beverages via skywave. Switching my beverages in different directions brought the signals up and down depending upon their direction. Since my preamp didn't have any selectivity built in, I was pretty sure this was going to happen. I tried a couple of filters that I had on the shelf. While both had some positive effect,one high pass filter had excessive insertion loss almost 10db.While it got rid of the harmonics, it also effectively eliminated the beneficial effect of my preamp on 160M. I swept the filter and found that it was a high pass filter alright, but one whose roll off was at 3.4 MHz! At 1.8 Mhz its loss was over 10 db. The other filter was a 160 BP unit, but didn't have enough poles to be effective below the band...the source of my problem. I then spoke with Dale, W4OP who sent me his BCST-HPF filter. When placed in series in front of my pre-amp..all of the BC Harmonics completely dissapeared! It was easy to check on them as the filter has an IN-OUT switch on its front panel. Using a modified metal Hammond chassis box, The unit is a tiny package, but the filter components are good sized toroids that allow exact adjustment of the filter poles for optimum BC band nulls (up to 80 db)while precisely setting the filters knee at 1.8MHz where the insertion loss is slightly less than 1 db. Other than the ubiquitous "Fish Buoy Beacons" and in band intruders, 160M is now a pleasure to listen to signals on. I highly recommend The Parr BCST-HPF filter as standard equipment for the serious 160M-80M operator. 73 Bruce Clark K0YW