re_nelson
2011-05-30, 03:47 AM
Unlike many of you, I'm not a very good DIY'er so my interest in antennas is largely confined to comparing the "as shipped" factory models. As noted elsewhere, I got extremely lucky several weeks back when I came across a classic CM-4228a that was about to be discarded.
My streak of good fortune continues as I recently obtained a refurbished AntennasDirect ClearStream C4 at a bargain price.
So I decided to put them to the test via a shootout in the attic (I know...I know) using the same short run of Monoprice RG-6 to the trusty Sencore SLM-1456. The smaller (and lighter) C4 appears to hold its own against the unmodified CM-4228a (the one with the 7-7/8" bowtie whiskers).
The performance (based on measured relative gain) seems to favor the CM-4228 on the low end of the UHF band. They both are very close as the frequencies increase with a slight edge to the C4 toward the upper channels.
Here's the TV Fool at my location (and note that KVFW/38) has been off the air for 2 months, so it's excluded from the measurements. We fortunate in that the extremes of the post-transition UHF band is used here in the Dallas area and there's a good dispersion of facilities in between 14 and 51.
ClearStream C4
+----+-----+-----+------+----+
! CH.!LEVEL! MER ! BER !DIG.!
+----+-----+-----+------+----+
! 14 ! -3.3! 31.2!2x10-7!PASS!
! 18 !-19.8! 29.0! <10-9!PASS!
! 19 ! -1.2! 35.2! <10-9!PASS!
! 20 !-19.6! 33.4! <10-9!PASS!
! 23 ! -0.9!>36.0! <10-9!PASS!
! 25 !-21.9!>36.0! <10-9!PASS!
! 27 !-22.1! 34.7! <10-9!PASS!
! 28 !-23.0! 32.7! <10-9!PASS!
! 29 ! 0.4!>36.0! <10-9!PASS!
! 30 ! 2.6!>36.0! <10-9!PASS!
! 31 !-20.8!>36.0!1x10-8!PASS!
! 32 ! -0.3!>36.0! <10-9!PASS!
! 34 !-20.6!>36.0! <10-9!PASS!
! 35 ! -1.9!>36.0! <10-9!PASS!
! 36 ! -1.6!>36.0! <10-9!PASS!
! 39 ! 2.9! 34.5! <10-9!PASS!
! 40 ! 0.7! 34.4! <10-9!PASS!
! 41 ! 1.2!>36.0! <10-9!PASS!
! 42 ! -0.9!>36.0! <10-9!PASS!
! 43 ! -5.5!>36.0! <10-9!PASS!
! 44 ! -9.4!>36.0! <10-9!PASS!
! 45 ! -4.5!>36.0! <10-9!PASS!
! 46 ! -8.1!>36.0! <10-9!PASS!
! 48 ! -1.7!>36.0! <10-9!PASS!
! 50 !-23.2!>36.0! <10-9!PASS!
! 51 !-24.8! 34.7! <10-9!PASS!
+----+-----+-----+------+----+
CM-4228a
+----+-----+-----+------+----+
! CH.!LEVEL! MER ! BER !DIG.!
+----+-----+-----+------+----+
! 14 ! -0.6! 32.8!2x10-8!PASS!
! 18 !-17.4! 30.1! <10-9!PASS!
! 19 ! 1.7!>36.0! <10-9!PASS!
! 20 !-18.3! 35.8! <10-9!PASS!
! 23 ! 2.8!>36.0! <10-9!PASS!
! 25 !-19.8!>36.0! <10-9!PASS!
! 27 !-21.0! 35.2! <10-9!PASS!
! 28 !-20.4! 33.3! <10-9!PASS!
! 29 ! -0.3!>36.0! <10-9!PASS!
! 30 ! 2.6!>36.0! <10-9!PASS!
! 31 !-21.7!>36.0!1x10-8!PASS!
! 32 ! -1.4!>36.0! <10-9!PASS!
! 34 !-20.8!>36.0! <10-9!PASS!
! 35 ! -2.0!>36.0! <10-9!PASS!
! 36 ! -1.7!>36.0! <10-9!PASS!
! 39 ! 3.5! 34.5! <10-9!PASS!
! 40 ! 1.0! 32.7! <10-9!PASS!
! 41 ! 1.3!>36.0! <10-9!PASS!
! 42 ! -1.4!>36.0! <10-9!PASS!
! 43 ! -6.0!>36.0! <10-9!PASS!
! 44 !-13.3!>36.0! <10-9!PASS!
! 45 ! -5.9!>36.0! <10-9!PASS!
! 46 ! -8.5!>36.0! <10-9!PASS!
! 48 ! -2.4!>36.0! <10-9!PASS!
! 50 !-24.8!>36.0! <10-9!PASS!
! 51 !-27.0! 33.6! <10-9!PASS!
+----+-----+-----+------+----+
My streak of good fortune continues as I recently obtained a refurbished AntennasDirect ClearStream C4 at a bargain price.
So I decided to put them to the test via a shootout in the attic (I know...I know) using the same short run of Monoprice RG-6 to the trusty Sencore SLM-1456. The smaller (and lighter) C4 appears to hold its own against the unmodified CM-4228a (the one with the 7-7/8" bowtie whiskers).
The performance (based on measured relative gain) seems to favor the CM-4228 on the low end of the UHF band. They both are very close as the frequencies increase with a slight edge to the C4 toward the upper channels.
Here's the TV Fool at my location (and note that KVFW/38) has been off the air for 2 months, so it's excluded from the measurements. We fortunate in that the extremes of the post-transition UHF band is used here in the Dallas area and there's a good dispersion of facilities in between 14 and 51.
ClearStream C4
+----+-----+-----+------+----+
! CH.!LEVEL! MER ! BER !DIG.!
+----+-----+-----+------+----+
! 14 ! -3.3! 31.2!2x10-7!PASS!
! 18 !-19.8! 29.0! <10-9!PASS!
! 19 ! -1.2! 35.2! <10-9!PASS!
! 20 !-19.6! 33.4! <10-9!PASS!
! 23 ! -0.9!>36.0! <10-9!PASS!
! 25 !-21.9!>36.0! <10-9!PASS!
! 27 !-22.1! 34.7! <10-9!PASS!
! 28 !-23.0! 32.7! <10-9!PASS!
! 29 ! 0.4!>36.0! <10-9!PASS!
! 30 ! 2.6!>36.0! <10-9!PASS!
! 31 !-20.8!>36.0!1x10-8!PASS!
! 32 ! -0.3!>36.0! <10-9!PASS!
! 34 !-20.6!>36.0! <10-9!PASS!
! 35 ! -1.9!>36.0! <10-9!PASS!
! 36 ! -1.6!>36.0! <10-9!PASS!
! 39 ! 2.9! 34.5! <10-9!PASS!
! 40 ! 0.7! 34.4! <10-9!PASS!
! 41 ! 1.2!>36.0! <10-9!PASS!
! 42 ! -0.9!>36.0! <10-9!PASS!
! 43 ! -5.5!>36.0! <10-9!PASS!
! 44 ! -9.4!>36.0! <10-9!PASS!
! 45 ! -4.5!>36.0! <10-9!PASS!
! 46 ! -8.1!>36.0! <10-9!PASS!
! 48 ! -1.7!>36.0! <10-9!PASS!
! 50 !-23.2!>36.0! <10-9!PASS!
! 51 !-24.8! 34.7! <10-9!PASS!
+----+-----+-----+------+----+
CM-4228a
+----+-----+-----+------+----+
! CH.!LEVEL! MER ! BER !DIG.!
+----+-----+-----+------+----+
! 14 ! -0.6! 32.8!2x10-8!PASS!
! 18 !-17.4! 30.1! <10-9!PASS!
! 19 ! 1.7!>36.0! <10-9!PASS!
! 20 !-18.3! 35.8! <10-9!PASS!
! 23 ! 2.8!>36.0! <10-9!PASS!
! 25 !-19.8!>36.0! <10-9!PASS!
! 27 !-21.0! 35.2! <10-9!PASS!
! 28 !-20.4! 33.3! <10-9!PASS!
! 29 ! -0.3!>36.0! <10-9!PASS!
! 30 ! 2.6!>36.0! <10-9!PASS!
! 31 !-21.7!>36.0!1x10-8!PASS!
! 32 ! -1.4!>36.0! <10-9!PASS!
! 34 !-20.8!>36.0! <10-9!PASS!
! 35 ! -2.0!>36.0! <10-9!PASS!
! 36 ! -1.7!>36.0! <10-9!PASS!
! 39 ! 3.5! 34.5! <10-9!PASS!
! 40 ! 1.0! 32.7! <10-9!PASS!
! 41 ! 1.3!>36.0! <10-9!PASS!
! 42 ! -1.4!>36.0! <10-9!PASS!
! 43 ! -6.0!>36.0! <10-9!PASS!
! 44 !-13.3!>36.0! <10-9!PASS!
! 45 ! -5.9!>36.0! <10-9!PASS!
! 46 ! -8.5!>36.0! <10-9!PASS!
! 48 ! -2.4!>36.0! <10-9!PASS!
! 50 !-24.8!>36.0! <10-9!PASS!
! 51 !-27.0! 33.6! <10-9!PASS!
+----+-----+-----+------+----+